S-4

      AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 9, 1999

                                                      REGISTRATION NO. 333-
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549
                            ------------------------

                                    FORM S-4

            REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
                            ------------------------

                           IRON MOUNTAIN INCORPORATED

             (Exact name of registrant as specified in its charter)

                                                        
          DELAWARE                         4226                        04-3107342
(State or other jurisdiction   (Primary Standard Industrial         (I.R.S. Employer
             of                 Classification Code Number)        Identification No.)
      incorporation or
        organization)



                                 CO-REGISTRANTS

                                (See next page)

                     745 ATLANTIC AVENUE, BOSTON, MA 02111

                                 (617) 535-4766

  (Address, including zip code, and telephone number, including area code, of
                   registrant's principal executive offices)
                         ------------------------------

                                C. RICHARD REESE
                            CHAIRMAN OF THE BOARD OF
                     DIRECTORS AND CHIEF EXECUTIVE OFFICER
                           IRON MOUNTAIN INCORPORATED
                              745 ATLANTIC AVENUE
                                BOSTON, MA 02111
                                 (617) 535-4766

 (Name, address, including zip code, and telephone number, including area code,
                             of agent for service)
                         ------------------------------

                                    COPY TO:

                             WILLIAM J. CURRY, ESQ.
                            SULLIVAN & WORCESTER LLP
                             ONE POST OFFICE SQUARE
                                BOSTON, MA 02109
                                 (617) 338-2800

    APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:  As soon as
practicable after this Registration Statement becomes effective.

    If the securities being registered on this form are being offered in
connection with the formation of a holding company and there is compliance with
General Instruction G, check the following box. / /

    If this form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, check the following box and
list the Securities Act registration statement number of the earlier effective
registration statement for the same offering. / /

    If this form is a post-effective amendment filed pursuant to Rule 462(d)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. / /

                        CALCULATION OF REGISTRATION FEE



                                                     PROPOSED MAXIMUM    PROPOSED MAXIMUM
TITLE OF EACH CLASS OF SECURITIES   AMOUNT TO BE      OFFERING PRICE    AGGREGATE OFFERING      AMOUNT OF
        TO BE REGISTERED             REGISTERED          PER UNIT             PRICE          REGISTRATION FEE
                                                                                
8 1/4% Senior Subordinated Notes
  Due 2011.......................   $150,000,000            --             $150,000,000          $41,700
Guarantees of the 8 1/4% Senior
  Subordinated Notes Due 2011....   $150,000,000           (2)                 (2)                 (2)


(1) Pursuant to Rule 457(f)(2) of the Securities Act of 1933, as amended, the
    registration fee has been estimated based on the book value of the
    securities to be received by the Registrant in exchange for the securities
    to be issued hereunder in the Exchange Offer described herein.

(2) Pursuant to Rule 457(n), no separate registration fee is required as no
    additional consideration is being paid for Guarantees.
                         ------------------------------

    THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

                                 CO-REGISTRANTS



                                                                              STATE OR OTHER
                                                                             JURISDICTION OF          FEDERAL
                                                                             INCORPORATION OR      IDENTIFICATION
        EXACT NAME OF CO-REGISTRANT AS SPECIFIED IN ITS CHARTER                ORGANIZATION            NUMBER
- -----------------------------------------------------------------------  ------------------------  --------------
                                                                                             

Arcus Data Security, Inc...............................................              Delaware          94-2148675

Arcus Data Security LLC................................................              Delaware          04-3462538

Arcus Staffing Resources, Inc..........................................              Delaware          94-3229868

Carter Media Management, Inc...........................................              Kentucky          61-1311186

Criterion Atlantic Property, Inc.......................................              Delaware          04-3102768

Datavault/United States Safe Deposit Company...........................            California          95-3769759

DSI Technology Escrow Services, Inc....................................              Delaware          77-0154485

HIMSCORP of Cleveland, Inc.............................................              Delaware          36-4072100

HIMSCORP of Detroit, Inc...............................................              Delaware          36-3994880

HIMSCORP of Houston, Inc...............................................              Delaware          36-4072098

HIMSCORP of Los Angeles, Inc...........................................              Delaware          36-4027036

HIMSCORP of New Orleans, Inc...........................................              Delaware          36-3994882

HIMSCORP of Philadelphia, Inc..........................................              Delaware          36-3998771

HIMSCORP of Pittsburgh, Inc............................................              Delaware          36-3994877

HIMSCORP of Portland, Inc..............................................              Delaware          91-1826931

HIMSCORP of San Diego, Inc.............................................              Delaware          36-4024320

IM-AEI Acquisition Corp................................................              Delaware          33-0486463

IM Billerica, Inc......................................................         Massachusetts          04-3373720

Iron Mountain Consulting Services, Inc.................................              Delaware          04-3241466

Iron Mountain of Maryland LLC..........................................              Delaware          52-2140928

Iron Mountain/National Underground Storage, Inc........................              Delaware          25-1016055

Iron Mountain Records Management, Inc..................................              Delaware          04-3038590

Iron Mountain Records Management of Michigan, Inc......................              Delaware          04-3346223

Iron Mountain Records Management of Ohio, Inc..........................              Delaware          31-1419399

Iron Mountain Records Management of San Antonio, Inc...................              Delaware          04-3376180

Iron Mountain Records Management of San Antonio--FP, Inc...............              Delaware          04-3377554

Iron Mountain Records Management of Utah, Inc..........................              Delaware          04-3402733

Iron Mountain Safe Deposit Corporation.................................              Michigan          04-3402751

Iron Mountain/Safesite, Inc............................................              Delaware          04-3071673

Recordkeepers, Inc.....................................................              Delaware          52-1578272


THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. WE MAY
NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION IS EFFECTIVE. THIS PROSPECTUS IS NOT AN OFFER
TO SELL THESE SECURITIES AND IT IS NOT SOLICITING AN OFFER TO BUY THESE
SECURITIES IN ANY STATE WHERE THE OFFER OR SALE IS NOT PERMITTED.

                   SUBJECT TO COMPLETION, DATED JULY 9, 1999

PROSPECTUS

                               OFFER TO EXCHANGE
                                ALL OUTSTANDING
                   8 1/4% SENIOR SUBORDINATED NOTES DUE 2011
                  ($150,000,000 PRINCIPAL AMOUNT OUTSTANDING)
                                      FOR
                   8 1/4% SENIOR SUBORDINATED NOTES DUE 2011
                                       OF

                           IRON MOUNTAIN INCORPORATED

    This is an offer to exchange our outstanding, unregistered 8 1/4% Senior
Subordinated Notes due 2011 you now hold for new, substantially identical 8 1/4%
Senior Subordinated Notes due 2011 that will be free of the transfer
restrictions that apply to the old Notes. This offer will expire at 5:00 p.m.,
New York City time, on             , 1999, unless we extend it. You must tender
your old, unregistered Notes by this expiration date to obtain new, registered
Notes and the liquidity they offer.

    We agreed with the initial purchasers of the old Notes to make this offer or
register the resale of the old Notes following the closing pursuant to a
registration rights agreement. An aggregate of $150 million in principal amount
of the old Notes is currently outstanding. We sometimes refer to the old Notes
and the new Notes together as the "Notes." This exchange offer applies to any
and all old Notes tendered by the expiration date.

    The new Notes will not trade on any established exchange. The new Notes have
the same financial terms and covenants as the old Notes and will continue to be
entitled to the benefits of the same indenture that governs the old Notes. The
Bank of New York will continue to act as trustee under the indenture.

    Below is a summary of the terms of the new Notes we are offering. For more
detail, see "Description of the New Notes."

    - The new Notes have a fixed annual interest rate of 8 1/4% that we will pay
      every six months on January 1 and July 1, commencing January 1, 2000.

    - The new Notes will mature on July 1, 2011.

    - The new Notes and the subsidiary guarantees are subordinated to some of
      our existing indebtedness and future indebtedness that we are permitted to
      incur under the indenture governing the new Notes. The new Notes will rank
      equally with our and our guarantor subsidiaries' other senior subordinated
      indebtedness.

    - If we sell certain assets or experience specific kinds of changes in
      control, we must offer to repurchase the new Notes.

    - We may, at our option, redeem the new Notes at any time prior to July 1,
      2004 at the make-whole price set for in this prospectus. At our option, we
      may also redeem the new Notes at any time after July 1, 2004 at the prices
      set forth in this prospectus. Before July 1, 2002, we may redeem up to 35%
      of the new Notes with the proceeds of certain types of public offerings of
      our equity.

    - If we cannot make payments on the new Notes when due, our guarantor
      subsidiaries must make them instead. Not all of our subsidiaries will be
      guarantors.

    SEE "RISK FACTORS" BEGINNING ON PAGE 12 TO READ ABOUT CERTAIN RISKS THAT YOU
SHOULD CONSIDER BEFORE INVESTING IN THE NEW NOTES.

    Neither the Securities and Exchange Commission nor any other regulatory body
has approved or disapproved of these securities or passed upon the adequacy or
accuracy of this prospectus. Any representation to the contrary is a criminal
offense.

               The date of this prospectus is             , 1999.

    WE HAVE NOT AUTHORIZED ANY PERSON TO GIVE YOU ANY INFORMATION OR MAKE ANY
REPRESENTATIONS TO YOU OTHER THAN THOSE CONTAINED IN THIS PROSPECTUS AND THE
ACCOMPANYING LETTER OF TRANSMITTAL, AND, IF GIVEN OR MADE, YOU MUST NOT RELY ON
SUCH INFORMATION OR REPRESENTATIONS AS HAVING BEEN AUTHORIZED BY IRON MOUNTAIN.
NEITHER THIS PROSPECTUS NOR THE ACCOMPANYING LETTER OF TRANSMITTAL, NOR BOTH
TOGETHER, NOR ANY SALE MADE HEREUNDER WILL UNDER ANY CIRCUMSTANCES CREATE AN
IMPLICATION THAT THERE HAS BEEN NO CHANGE IN THE AFFAIRS OF IRON MOUNTAIN SINCE
THE DATE HEREOF. NEITHER THIS PROSPECTUS NOR THE ACCOMPANYING LETTER OF
TRANSMITTAL, NOR BOTH TOGETHER, CONSTITUTE AN OFFER TO SELL OR SOLICITATION OF
AN OFFER TO BUY ANY OF OUR SECURITIES OFFERED HEREBY BY ANYONE IN ANY
JURISDICTION IN WHICH SUCH OFFER OR SOLICITATION IS NOT AUTHORIZED OR IN WHICH
THE PERSON MAKING SUCH OFFER OR SOLICITATION IS NOT QUALIFIED TO DO SO OR TO ANY
PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH OFFER OR SOLICITATION.

                               TABLE OF CONTENTS



                                                                                                                PAGE
                                                                                                                -----
                                                                                                          
Incorporation of Certain Information by Reference..........................................................           i
Where You Can Find Additional Information..................................................................          ii
Prospectus Summary.........................................................................................           1
Risk Factors...............................................................................................          12
Use of Proceeds............................................................................................          19
The Exchange Offer.........................................................................................          20
Selected Consolidated Financial and Operating Information..................................................          29
Description of Other Debt..................................................................................          31
Description of the New Notes...............................................................................          33
Material Federal Income Tax Considerations.................................................................          68
Plan of Distribution.......................................................................................          73
Transfer Restrictions......................................................................................          74
Legal Matters..............................................................................................          74
Experts....................................................................................................          75


               INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

    The SEC allows us to "incorporate by reference" the information we file with
them, which means that we can disclose important business and financial
information to you by referring you to those documents rather than including the
information directly herein. The information incorporated by reference is
considered to be part of this prospectus and information that we subsequently
file with the SEC will automatically update and supersede this information. We
incorporate by reference the documents listed below filed with the SEC (File No.
0-27584) under the Exchange Act.

    - Annual Report on Form 10-K for the fiscal year ended December 31, 1998,

    - Quarterly Report on Form 10-Q for the fiscal quarter added March 31, 1999,

    - Current Reports on Form 8-K dated October 30, 1997, November 25, 1997,
      March 9, 1998, September 18, 1998, January 19, 1999, March 3, 1999, April
      16, 1999, April 22, 1999, May 7, 1999, May 11, 1999 and July 9, 1999.

    - Current Reports on Form 8-K/A dated August 7, 1998 and March 22, 1999 and

    - Registration Statement on Form 8-A dated April 16, 1999.

    We also incorporate by reference each of the following documents that we
file with the SEC after the date of this prospectus but before the termination
of the exchange offer.

    - Reports filed under Section 13(a) and (c) of the Exchange Act,

                                       i

    - Definitive proxy or information statements filed under Section 14 of the
      Exchange Act in connection with any subsequent stockholders meeting and

    - Reports filed under Section 15(d) of the Exchange Act.

    You may request a copy of any of the filings, excluding exhibits unless the
exhibits are specifically incorporated by reference into this prospectus at no
cost, by writing or telephoning us at the following address:

                               John F. Kenny, Jr.

                          Executive Vice President and

                            Chief Financial Officer

                           Iron Mountain Incorporated

                              745 Atlantic Avenue

                          Boston, Massachusetts 02111

                                 (617) 535-4766

    To obtain timely delivery, you must request the information by no later than
five business days before you make your investment decision.

    Any statement contained in a document incorporated or deemed to be
incorporated by reference herein will be deemed to be modified or superseded for
purposes of this prospectus to the extent that a statement contained herein (or
in any other subsequently filed document which also is or is deemed to be
incorporated by reference herein) modifies or supersedes such statement. Any
such statement so modified or superseded shall not be deemed, except as so
modified or superseded, to constitute a part of this prospectus.

                   WHERE YOU CAN FIND ADDITIONAL INFORMATION

    We are subject to the informational requirements of the Securities Exchange
Act of 1934, and, accordingly, file annual, quarterly, and current reports,
proxy statements and other information with the SEC. You may read and copy
material filed by us with the SEC at the Public Reference Section of the SEC
located at Room 1024, Judiciary Plaza, 450 Fifth Street, N.W., Washington, D.C.
20549 and at regional public reference facilities maintained by the SEC located
at Citicorp Center, 500 West Madison Street, Suite 1400, Chicago, Illinois 60661
and Seven World Trade Center, Suite 1300, New York, New York 10048. Copies of
these materials can be obtained from the Public Reference Section of the SEC at
prescribed rates. Please call the SEC at 1-800-SEC-0330 for further information
on the Public Reference Section. You may access our electronic filings on the
SEC's Internet site, http://www.sec.gov which contains reports, proxy and
information statements and other information regarding issuers, including Iron
Mountain, that file electronically with the SEC.

    We have filed with the SEC a registration statement on Form S-4 under the
Securities Act with respect to the new Notes offered hereby. This prospectus
does not contain all of the information set forth in such registration statement
and the exhibits thereto, parts of which are omitted in accordance with the
rules and regulations of the SEC. For more information with respect to Iron
Mountain and the new Notes offered hereby, we refer you to the registration
statement, including the exhibits thereto, which is available for inspection and
copying as set forth above. Statements contained in this prospectus as to the
contents of any contract or other document referred to herein or therein are not
necessarily complete, although to the extent of the provisions referred to
herein, such statements are complete in all material respects, and in each
instance we refer you to the copy of such contract or other document filed as an
exhibit to the registration statement or such other document, each such
statement being qualified in all respects by such reference.

                                       ii

                               PROSPECTUS SUMMARY

    THIS SUMMARY HIGHLIGHTS INFORMATION CONTAINED ELSEWHERE IN THIS PROSPECTUS.
THIS SUMMARY IS NOT COMPLETE AND DOES NOT CONTAIN ALL OF THE INFORMATION THAT
YOU SHOULD CONSIDER BEFORE INVESTING IN THE NEW NOTES. YOU SHOULD READ THE
ENTIRE PROSPECTUS CAREFULLY, ESPECIALLY THE RISKS OF INVESTING IN OUR NOTES
DISCUSSED BELOW UNDER "RISK FACTORS." WE HAVE RESTATED ALL SHARE AND PER SHARE
AMOUNTS IN THIS PROSPECTUS TO REFLECT A THREE-FOR-TWO STOCK SPLIT EFFECTED IN
THE FORM OF A STOCK DIVIDEND ON OUR COMMON STOCK ON JULY 31, 1998.

                                 IRON MOUNTAIN

    Iron Mountain Incorporated is the world's largest records and information
management services company, as measured by its revenues. We are an
international, full-service provider of records and information management
services, enabling customers to outsource these functions. We have a diversified
customer base that includes more than half of the Fortune 500. We provide
storage for all major media, including paper, which is the dominant form of
records storage, and magnetic media, including computer tapes. Our principal
services provided to our storage customers include courier pick-up and delivery,
filing, retrieval and destruction of records, database management, customized
reporting and disaster recovery support. We also sell storage materials,
including cardboard boxes and magnetic media, and provide consulting, facilities
management and other outsourcing services.

    We believe that we are the industry leader in business records management
services, off-site data security services, which is the management of electronic
records, and healthcare information management. As of March 31, 1999, giving
effect to our 1999 acquisitions completed through April 30, 1999 and Britannia
Data Management Limited's acquisition of MAP, S.A. and its operating subsidiary
Memogarde S.A., we operated over 300 records and information management services
centers in 66 domestic markets, four markets in the United Kingdom and one
market in France, servicing over 70,000 customer accounts. Giving effect on a
pro forma basis to our 1999 acquisitions completed through April 30, 1999 and
Britannia Data Management's acquisition of Memogarde, we had revenues from
continuing operations of approximately $126 million for the quarter ended March
31, 1999 and EBITDA from continuing operations of approximately $31 million for
the same period. We use the term EBITDA to refer to earnings before interest,
taxes, depreciation, amortization, extraordinary items and other income. For the
same period, after adjustments for specific identified cost reductions from the
integration of our 1999 acquisitions completed through April 30, 1999 and
Britannia Data Management's acquisition of Memogarde, our pro forma EBITDA from
continuing operations would have been approximately $32 million for the quarter
ended March 31, 1999. We have included in pro forma revenues and EBITDA from
continuing operations 100% of the consolidated results of our 50.1% owned
subsidiary, Britannia Data Management Limited, and its wholly owned subsidiary
Memogarde. Britannia Data Management had revenues of $8.1 million and EBITDA of
$2.1 million for its quarter ended January 31, 1999, based on an average
exchange rate of $1.6530 per L1 for such period. Memogarde had revenues of $1.1
million and EBITDA of $0.5 million for its quarter ended May 31, 1999, based on
an average exchange rate of 6.1079 French francs per $1 for this period.

                              RECENT DEVELOPMENTS

INTERNATIONAL ACTIVITY

    On January 4, 1999, we purchased a controlling 50.1% interest in Britannia
Data Management for consideration of $49.3 million. Mentmore Abbey plc is our
partner in this venture, holding the remaining 49.9% interest. As of December
31, 1998, Britannia Data Management operated 16 data storage facilities in the
United Kingdom and had over 1,500 customer accounts. Britannia Data Management
had revenues of $30.3 million for its fiscal year ended October 31, 1998, based
on an average exchange rate of $1.6622 per L1 for this period.

                                       1

    On June 2, 1999, Britannia Data Management acquired Memogarde and related
companies for aggregate consideration of $16.9 million, based on an exchange
rate of 6.2699 French francs per $1 on June 2, 1999. Memogarde, headquartered
and operating in Paris, France, is a leading provider of data security services
in France. Memogarde had revenues of $4.3 million for its fiscal year ended
February 28, 1999, based on an average exchange rate of 5.8448 French francs per
$1 for this period.

    The acquisition of Britannia Data Management marked our first large
international investment. We believe there are significant opportunities to
acquire records and information management services companies internationally,
and expect to continue our international expansion. Europe and Latin America are
our primary areas of focus for our international expansion at this time, and we
are actively pursuing opportunities in these areas. We intend to use Britannia
Data Management as our primary vehicle for acquisitions in Europe, as was the
case with our Memogarde acquisition. As we expand internationally, we expect
that some of our acquisitions will be in the form of joint ventures or
acquisitions of less than 100% ownership of companies, as we did with Britannia
Data Management. This will allow us to reduce the risks of entering new markets
and to work with local partners who can provide local market knowledge and
regional management expertise and have an established presence within the
community.

RECENT EQUITY OFFERING

    On May 17, 1999, we completed an underwritten public offering of 5,750,000
shares of our common stock at a price to the public of $28.00 per share
(including 750,000 as a result of the underwriters' exercise of their
overallotment option). We used a portion of the net proceeds from this offering
to repurchase all of the 1,476,577 shares of our common stock issued in our
acquisition of Data Base, Inc. at a price of $26.74 per share and to repay debt.
We will use the remainder of the net proceeds for general corporate purposes,
including future acquisitions.

DATA BASE ACQUISITION

    On April 8, 1999, we acquired all of the outstanding capital stock of Data
Base, Inc. and certain related real estate for aggregate consideration of
approximately $116 million, including estimated transaction costs. This amount
consisted of (a) approximately $70 million of assumed indebtedness and cash
payments to Data Base's stockholders and to the owner of the real estate and for
related expenses and (b) 1,476,577 shares of our common stock. On May 18, 1999,
we repurchased all 1,476,577 shares of our common stock that we issued to Data
Base's stockholders at a price of $26.74 per share from a portion of the net
proceeds of our May 1999 equity offering. We believe that Data Base is a premier
provider of data security services, with over 3,000 customers. Data Base's
services are comprised primarily of off-site data security services, including
secure transport, handling and storage of electronic media, and disaster
recovery support services which facilitate the restoration of corporate data at
a recovery site. As of April 8, 1999, Data Base operated in 12 markets in the
United States. Data Base had revenues of $26.6 million for the year ended
December 31, 1998.

FIRST AMERICAN RECORDS MANAGEMENT ACQUISITION

    On April 1, 1999, we acquired First American Records Management, Inc. for
consideration of $41.5 million. First American Records Management provides
records and information management services, including data security services,
in several locations in California and the Pacific Northwest. As of April 1,
1999, First American Records Management operated in five markets, serving
approximately 1,000 customer accounts. First American Records Management had
revenues of $9.9 million for the year ended December 31, 1998.

                                       2

OTHER 1999 ACQUISITIONS

    Through June 30, 1999, we acquired five additional records and information
management services companies, including one in Puerto Rico, for total
consideration of $9.1 million. These companies had total revenues of $7.4
million for the year ended December 31, 1998.

ARCUS STAFFING

    In order to focus on our records and information management services
business, we have decided to sell our information technology staffing business,
Arcus Staffing Resources, Inc. We acquired Arcus Staffing in January 1998 as
part of our acquisition of Arcus Group, Inc. We intend to complete this
transaction in the second half of 1999, though we can give no assurance in this
regard. In 1998, Arcus Staffing had EBITDA of $1.5 million on revenues of $39.6
million.

    We will account for the sale of Arcus Staffing as a discontinued operation.
Accordingly, Arcus Staffing has been segregated from our continuing operations
and reported as a separate line item on our consolidated statements of
operations. We expect to report a loss on the sale of Arcus Staffing in our
second quarter results. We cannot determine the amount of the loss at this time.
We will report the loss separately from the results of our continuing
operations.

                          ADDRESS AND TELEPHONE NUMBER

    Iron Mountain was incorporated in Delaware in 1990 but its operations date
from 1951. Our principal executive offices are located at 745 Atlantic Avenue,
Boston, Massachusetts 02111. Our telephone number is (617) 535-4766.

                                       3

                   SUMMARY OF THE TERMS OF THE EXCHANGE OFFER

                             
THE EXCHANGE OFFER............  We are offering to exchange $1,000 in principal amount, and
                                integral multiples in excess thereof, of new Notes for each
                                $1,000 in principal amount, and any integral multiples in
                                excess thereof, of old Notes that you validly tender
                                pursuant to the exchange offer. We will issue the new Notes
                                promptly after the expiration date of the exchange offer.
                                The exchange offer is not conditioned upon any minimum
                                principal amount of old Notes being tendered for exchange.
                                As of the date of this prospectus, $150,000,000 in aggregate
                                principal amount of old Notes are outstanding.

RESALE........................  We believe, based on no-action letters issued by the SEC to
                                third parties, that the new Notes issued pursuant to the
                                exchange offer generally will be freely transferable by you
                                without registration or any prospectus delivery requirement
                                under the Securities Act. If, however, you are a "dealer" or
                                our "affiliate," as such terms are defined under the
                                Securities Act, and you exchange old Notes held for your own
                                account, you may be required to deliver copies of this
                                prospectus in connection with any resale of the new Notes
                                issued in exchange for such old Notes. See "The Exchange
                                Offer-- General" and "Plan of Distribution."

EXPIRATION DATE...............  The exchange offer will expire at 5:00 p.m., New York City
                                time, on             , 1999, unless we extend it, in which
                                case the term "expiration date" means the latest date and
                                time to which we extend the exchange offer. We will accept
                                for exchange any and all old Notes that you validly tender
                                in the exchange offer prior to 5:00 p.m., New York City
                                time, on the expiration date.

ACCRUED INTEREST ON THE NEW
  NOTES AND THE OLD NOTES.....  Each new Note will bear interest from the last interest
                                payment date on which interest was paid on the old Notes. We
                                will pay such interest with the first interest payment on
                                the new Notes. Accordingly, interest which has accrued since
                                the last interest payment date on the old Notes accepted for
                                exchange will cease to be payable upon issuance of the new
                                Notes. Untendered old Notes that you do not exchange for new
                                Notes pursuant to the exchange offer will continue to bear
                                interest at a rate of 8 1/4% per annum after the expiration
                                date of the exchange offer.



                                       4


                             
TERMINATION...................  We may terminate the exchange offer if we determine that our
                                ability to proceed with the exchange offer could be
                                materially impaired due to any legal or governmental action,
                                any new law, statute, rule or regulation or any
                                interpretation by the SEC staff of any existing law,
                                statute, rule or regulation. You will have certain rights
                                against us under the registration rights agreement should we
                                fail to complete the exchange offer. See "The Exchange
                                Offer-- Termination." We are not required to comply with any
                                federal or state regulatory requirements or to obtain any
                                approvals in connection with the exchange offer, other than
                                applicable requirements under federal and state securities
                                laws.

PROCEDURES FOR TENDERING
  OLD NOTES...................  If you wish to accept the exchange offer, you must complete,
                                sign and date a letter of transmittal, or a facsimile
                                thereof, in accordance with the instructions contained
                                herein and therein, and mail or otherwise deliver such
                                letter of transmittal, or such facsimile, together with your
                                old Notes and any other required documentation to The Bank
                                of New York, our exchange agent, at the address set forth
                                herein and therein, or effect a tender of old Notes pursuant
                                to the procedure for book-entry transfer as provided for
                                herein. By executing the letter of transmittal, you will
                                represent to us that, among other things, you are obtaining
                                the new Notes pursuant to the exchange offer in the ordinary
                                course of your business, whether or not you are the holder,
                                that neither you nor any such other person has an
                                arrangement or understanding with any person to participate
                                in the distribution of such new Notes and, except as
                                otherwise disclosed in writing to us, that neither you nor
                                any such other person is an "affiliate," as defined in Rule
                                405 under the Securities Act, of Iron Mountain.

SPECIAL PROCEDURES FOR
  BENEFICIAL OWNERS...........  If you are a beneficial owner whose old Notes are registered
                                in the name of a broker, dealer, commercial bank, trust
                                company or other nominee and you wish to tender such old
                                Notes in the exchange offer, you should contact the
                                registered holder promptly and instruct such registered
                                holder to tender on your behalf. If you wish to tender on
                                your own behalf, you must, prior to completing and executing
                                the letter of transmittal and delivering your old Notes,
                                either make appropriate arrangements to register ownership
                                of the old Notes in your name or obtain a properly completed
                                bond power from the registered holder. The transfer of
                                record ownership may take considerable time and may not be
                                able to be completed prior to the expiration date of the
                                exchange offer.

GUARANTEED DELIVERY
  PROCEDURES..................  If you wish to tender your old Notes and they are not
                                immediately available or you cannot deliver them, the letter
                                of transmittal or any other documents required by the letter
                                of transmittal to our exchange agent prior to the expiration
                                date, you must tender your old Notes according to the
                                guaranteed delivery procedures set forth in "The Exchange
                                Offer--Guaranteed Delivery Procedures."



                                       5


                             
WITHDRAWAL RIGHTS.............  You may withdraw your tender of old Notes at any time prior
                                to 5:00 p.m., New York City time, on the later of       ,
                                1999 or the expiration date of the exchange offer.

ACCEPTANCE OF OLD NOTES AND
  DELIVERY OF NEW NOTES.......  Subject to certain conditions as summarized above in "--
                                Termination" and described more fully in "The Exchange
                                Offer-- Termination," we will accept for exchange any and
                                all old Notes that are validly tendered in the exchange
                                offer prior to 5:00 p.m., New York City time, on the later
                                of       , 1999 or the expiration date of the exchange
                                offer. The new Notes issued pursuant to the exchange offer
                                will be delivered promptly following such date. See "The
                                Exchange Offer--General."

MATERIAL FEDERAL INCOME TAX
  CONSIDERATIONS..............  The exchange pursuant to the exchange offer will generally
                                not be a taxable event for federal income tax purposes. For
                                a discussion of material federal income tax considerations
                                relating to the exchange of the old Notes for the new Notes,
                                see "Material Federal Income Tax Considerations."

ACCOUNTING TREATMENT..........  We will record the new Notes at the same carrying value as
                                the old Notes, and we will not recognize any gain or loss
                                for accounting purposes upon completion of the exchange
                                offer.

APPRAISAL/DISSENTERS'
  RIGHTS......................  You do not have any appraisal or dissenters' rights under
                                the Delaware General Corporation Law or the indenture in
                                connection with the exchange offer.

EXCHANGE AGENT................  The trustee is also our exchange agent. The mailing address
                                of the exchange agent and the address for deliveries by
                                registered or certified mail is: The Bank of New York, 101
                                Barclay Street--7E, New York, New York 10286, Attention:
                                Noriko Miyazaki, Reorganization Section. Hand deliveries or
                                overnight deliveries should be directed to The Bank of New
                                York, 101 Barclay Street, Corporate Trust Services Window,
                                Ground Level, New York, New York 10286, Attention: Noriko
                                Miyazaki, Reorganization Section. For information with
                                respect to the exchange offer, the telephone number for our
                                exchange agent is (212) 815-6333.

USE OF PROCEEDS...............  We will not receive any proceeds from the issuance of the
                                new Notes pursuant to the exchange offer. The net proceeds
                                received by us from the sale of the old Notes were used to
                                repay indebtedness under our revolving credit facility.



                                       6

                     SUMMARY OF THE TERMS OF THE NEW NOTES

    The exchange offer applies to an aggregate principal amount of $150.0
million of the old Notes. The form and terms of the new Notes will be the same
as the form and terms of the old Notes except that the new Notes will not bear
legends restricting the transfer thereof. The new Notes will be obligations of
Iron Mountain entitled to the benefits of the indenture. See "Description of the
New Notes."

                             
ISSUER........................  Iron Mountain Incorporated.

NOTES OFFERED.................  We are offering a total of $150.0 million in principal
                                amount of 8 1/4% Senior Subordinated Notes due 2011.

MATURITY DATE.................  July 1, 2011.

INTEREST......................  We will pay interest on the new Notes at a fixed annual
                                interest rate of 8 1/4%. We will pay the interest due on the
                                new Notes every six months on January 1 and July 1. We made
                                our first interest payment on the old Notes on July 1, 1999
                                and we will make our first interest payment on the new Notes
                                on January 1, 2000.

SUBSIDIARY GUARANTORS.........  Each guarantor is one of our wholly owned subsidiaries.
                                However, not all of our subsidiaries are guarantors. If we
                                cannot make payments on the new Notes when they are due, the
                                guarantor subsidiaries must make them instead.

RANKING.......................  The new Notes and the subsidiary guarantees are unsecured
                                senior subordinated debts. They rank behind all of our and
                                our guarantor subsidiaries' current and future indebtedness
                                (other than trade payables), except indebtedness that
                                expressly provides that it is not senior to the new Notes
                                and the guarantees. Giving effect to our 1999 acquisitions
                                completed through April 30, 1999 and our acquisition of
                                Memogarde, the offering of the old Notes and our May 1999
                                public equity offering, on March 31, 1999, the new Notes and
                                the subsidiary guarantees:

                                    - would have been subordinated to $6.2 million of senior
                                    debt and

                                    - would have ranked equally with $429.9 million of other
                                      senior subordinated debt and trade payables.

MANDATORY OFFER TO              If we sell certain assets or experience specific kinds of
  REPURCHASE..................  changes of control, we must offer to repurchase the new
                                Notes at the prices listed in the section "Description of
                                the New Notes" under the heading "Repurchase at the Option
                                of Holders."

OPTIONAL REDEMPTION...........  We may, at our option, redeem the new Notes at any time
                                prior to July 1, 2004 at the make-whole price set forth in
                                this prospectus. At our option, we may also redeem some or
                                all of the new Notes at any time after July 1, 2004, at the
                                redemption prices listed in the section "Description of the
                                New Notes" under the heading "Optional Redemption."



                                       7


                             
                                Before July 1, 2002, we may redeem up to 35% of the new
                                Notes with the proceeds of certain public offerings of our
                                equity at the price listed in the section "Description of
                                the New Notes" under the heading "Optional Redemption."

CERTAIN COVENANTS.............  The indenture with The Bank of New York, among other things,
                                restricts our ability and the ability of our restricted
                                subsidiaries to:

                                    - borrow money,

                                    - pay dividends on stock or purchase stock,

                                    - make investments,

                                    - use assets as security in other transactions,

                                    - enter into transactions with affiliates and

                                    - sell certain assets or merge with or into other
                                      companies.

                                For more details, see the section "Description of the New
                                Notes" under the heading "Certain Covenants."

REGISTRATION RIGHTS AND
  LIQUIDATED DAMAGES..........  Under the registration rights agreement executed as part of
                                the offering of the old Notes, we have agreed to:

                                    - use our best efforts to cause the registration
                                    statement to become effective no later than October 23,
                                      1999,

                                    - complete the exchange offer within 30 days, or such
                                    longer period as may be required by law, after the
                                      effective date of the registration statement and

                                    - use our best efforts to file a shelf registration
                                    statement for the resale of the old Notes if we cannot
                                      effect an exchange offer within the time periods
                                      listed above and in certain other circumstances.

                                If we do not comply with our obligations under the
                                registration rights agreement, we will be required to pay
                                specified liquidated damages to the holders of the old Notes
                                under certain circumstances.



                                  RISK FACTORS

    You should carefully consider all of the information in this prospectus. In
particular, you should evaluate the specific risks set forth under "Risk
Factors" beginning on page 12 for a discussion of certain risks in making an
investment in the new Notes.

                                       8

                  SUMMARY HISTORICAL AND PRO FORMA INFORMATION
                                 (IN THOUSANDS)

    The following table contains certain summary financial information with
respect to Iron Mountain. The historical information for each of the years ended
December 31, 1994, 1995, 1996, 1997 and 1998 is derived from Iron Mountain's
audited consolidated financial statements. The historical information for the
three months ended March 31, 1999 is derived from our unaudited consolidated
financial statements. You should read this historical and pro forma information
in conjunction with "Selected Consolidated Financial and Operating Information"
and the footnotes thereto, included elsewhere in this prospectus, and with
"Management's Discussion and Analysis of Financial Condition and Results of
Operations," "Pro Forma Condensed Consolidated Financial Information" and the
footnotes thereto and Iron Mountain's Consolidated Financial Statements and the
footnotes thereto incorporated by reference in this prospectus. See
"Incorporation of Certain Documents by Reference."



                                                                                                    THREE MONTHS ENDED
                                              YEAR ENDED DECEMBER 31,                                    MARCH 31,
                         ------------------------------------------------------------------  ---------------------------------
                                                                                    PRO                                PRO
                                              HISTORICAL                         FORMA(1)         HISTORICAL        FORMA(1)
                         -----------------------------------------------------  -----------  --------------------  -----------
                           1994       1995       1996       1997       1998        1998        1998       1999        1999
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
                                                                                        
CONSOLIDATED STATEMENTS
  OF OPERATIONS DATA:
Revenues:
    Storage............  $  54,098  $  64,165  $  85,826  $ 125,968  $ 230,702   $ 299,844   $  52,948  $  67,722   $  80,801
    Service and Storage
      Material Sales...     33,520     40,271     52,892     82,797    153,259     175,548      36,108     41,649      45,301
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
        Total
          Revenues.....     87,618    104,436    138,718    208,765    383,961     475,392      89,056    109,371     126,102
Operating Expenses:
    Cost of Sales
      (Excluding
      Depreciation)....     45,880     52,277     70,747    106,879    192,113     236,478      44,917     54,435      62,599
    Selling, General
      and
      Administrative...     20,853     26,035     34,342     51,668     95,867     119,294      22,360     27,875      32,379
    Depreciation and
      Amortization.....      8,690     12,341     16,936     27,107     48,301      63,247      11,058     13,595      16,324
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
        Total Operating
          Expenses.....     75,423     90,653    122,025    185,654    336,281     419,019      78,335     95,905     111,302
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
Operating Income.......     12,195     13,783     16,693     23,111     47,680      56,373      10,721     13,466      14,800
Interest Expense,
  Net..................      8,954     11,838     14,901     27,712     45,673      54,944      12,314     11,944      13,384
Other Income, Net(2)...         --         --         --         --      1,384       1,384          --         --          --
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
Income (Loss) from
  Continuing Operations
  Before Provision
  (Benefit) for Income
  Taxes and Minority
  Interest.............      3,241      1,945      1,792     (4,601)     3,391       2,813      (1,593)     1,522       1,416
Provision (Benefit) for
  Income Taxes.........      1,957      1,697      1,435        (80)     6,558       7,759      (1,045)     1,623       1,869
Minority Interest in
  Net Income of
  Consolidated
  Subsidiaries(3)......         --         --         --         --         --         928          --        147         290
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
Income (Loss) from
  Continuing
  Operations...........      1,284        248        357     (4,521)    (3,167)     (5,874)       (548)      (248)       (743)
Income from
  Discontinued
  Operations (net of
  tax provision).......         --         --         --         --        201         201         234         99          99
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
Income (Loss) Before
  Extraordinary
  Charge...............      1,284        248        357     (4,521)    (2,966)     (5,673)       (314)      (149)       (644)
Extraordinary Charge,
  Net of Tax
  Benefit(4)...........         --         --      2,126         --         --          --          --         --          --
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
Net Income (Loss)
  Before Warrant
  Accretion............  $   1,284  $     248  $  (1,769) $  (4,521) $  (2,966)  $  (5,673)  $    (314) $    (149)  $    (644)
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------


                                       9




                                                                                                    THREE MONTHS ENDED
                                              YEAR ENDED DECEMBER 31,                                    MARCH 31,
                         ------------------------------------------------------------------  ---------------------------------
                                                                                    PRO                                PRO
                                              HISTORICAL                         FORMA(1)         HISTORICAL        FORMA(1)
                         -----------------------------------------------------  -----------  --------------------  -----------
                           1994       1995       1996       1997       1998        1998        1998       1999        1999
                         ---------  ---------  ---------  ---------  ---------  -----------  ---------  ---------  -----------
                                                                                        
OTHER DATA:
Ratio of Earnings to
  Fixed Charges(5).....       1.2x       1.1x       1.1x       0.9x       1.1x        1.0x        0.9x       1.1x        1.1x
EBITDA from Continuing
  Operations(6)........  $  20,885  $  26,124  $  33,629  $  50,218  $  95,981   $ 119,620   $  21,779  $  27,061   $  31,124
EBITDA from Continuing
  Operations as a
  Percentage of Total
  Revenues.............       23.8%      25.0%      24.2%      24.1%      25.0%       25.2%       24.5%      24.7%       24.7%
Capital Expenditures:
  Growth(7)(8).........  $  15,829  $  14,395  $  23,334  $  37,082  $  54,039               $   9,545  $  17,642
  Maintenance(9).......      1,151        858      1,112      1,238      1,888                     576        651
                         ---------  ---------  ---------  ---------  ---------               ---------  ---------
    Total Capital
      Expenditures(8)..  $  16,980  $  15,253  $  24,446  $  38,320  $  55,927               $  10,121  $  18,293
                         ---------  ---------  ---------  ---------  ---------               ---------  ---------
                         ---------  ---------  ---------  ---------  ---------               ---------  ---------




                                                                                                     AS OF OR FOR
                                                                                                      THE PERIOD
                                                                                                         ENDED
                                                                                                    MARCH 31, 1999
                                                                                                    ---------------
                                                                                                 
ADJUSTED EBITDA AND CREDIT RATIOS(10):
Adjusted EBITDA(11)...............................................................................     $ 121,004
Cash Interest Expense(12).........................................................................        50,593
Ratio of Adjusted EBITDA to Cash Interest Expense.................................................           2.4x
Ratio of Total Debt to Adjusted EBITDA(13)........................................................           4.7x




                                                                                          AS OF MARCH 31, 1999
                                                                                         ----------------------
                                                                                              
                                                                                                        PRO
                                                                                         HISTORICAL  FORMA(14)
                                                                                         ---------  -----------
CONSOLIDATED BALANCE SHEET DATA:
Cash and Cash Equivalents..............................................................  $   4,899   $  50,043
Total Assets...........................................................................  1,052,744   1,282,006
Total Debt.............................................................................    541,315     604,318
Stockholders' Equity...................................................................    338,857     498,773


- ------------------------------

 (1) Gives effect to: (a) the 1998 and 1999 acquisitions we completed through
     April 30, 1999 and the acquisition of Memogarde by Britannia Data
     Management, (b) our public equity offerings completed in April 1998 and May
     1999 and (c) the offering of the old Notes and the application of the net
     proceeds therefrom as described under "Use of Proceeds," as if each had
     occurred as of January 1, 1998. See "Use of Proceeds" and "Pro Forma
     Condensed Consolidated Financial Information." The pro forma information
     does not give effect to identified cost savings of $6.7 million for the
     year ended December 31, 1998 or $1.2 million for the three months ended
     March 31, 1999 that we believe would have been realized had the 1998 and
     1999 acquisitions we completed through April 30, 1999 and the acquisition
     of Memogarde by Britannia Data Management been fully integrated as of
     January 1, 1998 relating to: (a) termination of specific employees and
     related net reductions in labor expenses, (b) closure of identified
     redundant facilities and related net reductions in occupancy costs and (c)
     elimination of related party expenses, management fees and compensation
     expenses in excess of amounts that would have been incurred by Iron
     Mountain.

 (2) Other income, net includes a $1.7 million gain resulting from the
     settlement of several insurance claims related to the March 1997 fires at
     our South Brunswick Township, New Jersey facilities.

 (3) Minority interest represents 49.9% of the total equity of Britannia Data
     Management after giving pro forma effect to the issuance of capital stock
     to Iron Mountain in exchange for cash and the net assets of Arcus Data
     Security Limited, our existing data security business in London.

 (4) The extraordinary charge consists of a prepayment penalty, the write-off of
     deferred financing costs, original issue discount and loss on termination
     of interest rate protection agreements.

 (5) We reported a loss from continuing operations, before benefit for income
     taxes and minority interest, for the year ended December 31, 1997 and for
     the three months ended March 31, 1998. For such periods we would have
     needed to generate additional income from continuing operations, before
     provision (benefit) for income taxes and minority interest, of $4,601 and
     $1,583, respectively, to cover our fixed charges of $37,489 and $14,191,
     respectively.

 (6) Based on our experience in the records and information management services
     industry, we believe that EBITDA is an important tool for measuring the
     performance of records and information management services companies
     (including

                                       10

     potential acquisition targets) in several areas, such as liquidity,
     operating performance and leverage. In addition, lenders use EBITDA in
     evaluating records and information management services companies, and
     substantially all of our financing agreements contain covenants in which
     EBITDA is used as a measure of financial performance. However, you should
     not consider EBITDA to be a substitute to operating or net income (as
     determined in accordance with GAAP) as an indicator of our performance or
     to cash flow from operations (as determined in accordance with GAAP) as a
     measure of liquidity. Pro forma revenue and EBITDA information included in
     this Offering Memorandum give effect to 100% of the consolidated revenues
     and EBITDA of Britannia Data Management for the applicable periods without
     reduction for the 49.9% minority interest.

 (7) Growth capital expenditures consist primarily of investments in racking
     systems, management information systems, new buildings and expansion of
     storage capacity in existing facilities.

 (8) Includes $2,901 in 1994 related to the cost of constructing a records and
     information management services facility which was sold in a sale and
     leaseback transaction in 1994.

 (9) Consists of capital expenditures we made in order to maintain our current
     revenues.

 (10) Britannia Data Management and its subsidiaries are not restricted
      subsidiaries for purposes of the indenture. As a result, their EBITDA,
      cash interest expense and total indebtedness are not included for purposes
      of the indenture or these calculations. However, Arcus Staffing is still a
      restricted subsidiary and, as a result, its EBITDA, cash interest expense
      and total indebtedness are included for purposes of the indenture and
      these calculations.

 (11) Represents Adjusted EBITDA, as calculated for purposes of the indenture,
      based on (a) Iron Mountain's and our restricted subsidiaries' EBITDA for
      the most recent quarter multiplied by four, (b) EBITDA of businesses Iron
      Mountain or our restricted subsidiaries have acquired or will acquire for
      their most recent fiscal quarter (appropriately reduced to the extent
      their EBITDA is already included in Iron Mountain's and our restricted
      subsidiaries' EBITDA) multiplied by four and (c) quantifiable improvements
      in operating results, on an annualized basis, due to cost reductions that
      we project in good faith, without giving effect to any operating losses of
      the business we acquired or will acquire from the businesses referred to
      in clause (b). Adjusted EBITDA, as calculated for purposes of the
      indenture, differs from our pro forma EBITDA, as presented elsewhere in
      this Offering Memorandum. We will use Adjusted EBITDA for purposes of debt
      incurrence under the indenture. You should not view Adjusted EBITDA as
      indicative of actual or future results. See "Description of the New
      Notes--Certain Covenants--Incurrence of Indebtedness and Issuance of
      Preferred Stock" and "--Certain Definitions."

 (12) Cash interest expense represents total interest expense of Iron Mountain
      and our restricted subsidiaries less amortization of deferred financing
      costs and other non-cash interest charges for the twelve months ended
      March 31, 1999 on a pro forma basis giving effect to (a) the 1998 and 1999
      acquisitions we completed through April 30, 1999 and the acquisition of
      Memogarde by Britannia Data Management, (b) our 1998 and 1999 public
      equity offerings and (c) the offering of the old Notes and the application
      of the net proceeds therefrom as described under "Use of Proceeds," as if
      each had occurred on April 1, 1998.

 (13) Based on pro forma total debt as of March 31, 1999.

 (14) Gives effect to: (a) the 1999 acquisitions we completed in April 1999 and
      the acquisition of Memogarde by Britannia Data Management, (b) our 1999
      equity offering and the application of the net proceeds therefrom as
      intended and (c) the offering of the old Notes and the application of the
      net proceeds therefrom as described under "Use of Proceeds," as if each
      had occurred as of March 31, 1999. See "Use of Proceeds."

                                       11

                                  RISK FACTORS

    YOU SHOULD CAREFULLY CONSIDER THE FOLLOWING RISK FACTORS, IN ADDITION TO THE
OTHER INFORMATION IN THIS PROSPECTUS, BEFORE EXCHANGING YOUR OLD NOTES FOR NEW
NOTES. THIS PROSPECTUS INCLUDES AND INCORPORATES BY REFERENCE "FORWARD LOOKING
STATEMENTS" WITHIN THE MEANING OF SECTION 27A OF THE SECURITIES ACT AND SECTION
21E OF THE EXCHANGE ACT INCLUDING, IN PARTICULAR, THE STATEMENTS ABOUT OUR
GOALS, BELIEFS, PLANS, STRATEGIES AND CURRENT EXPECTATIONS IN "PROSPECTUS
SUMMARY." ALTHOUGH WE BELIEVE THAT OUR GOALS, BELIEFS, PLANS, STRATEGIES AND
CURRENT EXPECTATIONS REFLECTED IN OR SUGGESTED BY SUCH FORWARD-LOOKING
STATEMENTS ARE REASONABLE, WE CAN GIVE NO ASSURANCE THAT SUCH GOALS, BELIEFS,
PLANS, STRATEGIES OR EXPECTATIONS WILL BE ACHIEVED. IMPORTANT FACTORS THAT COULD
CAUSE ACTUAL RESULTS TO DIFFER MATERIALLY FROM THE FORWARD-LOOKING STATEMENTS WE
MAKE IN THIS PROSPECTUS ARE SET FORTH BELOW AND ELSEWHERE IN THIS PROSPECTUS.
ALL FORWARD-LOOKING STATEMENTS ATTRIBUTABLE TO US OR PERSONS ACTING ON OUR
BEHALF ARE EXPRESSLY QUALIFIED IN THEIR ENTIRETY BY THE FOLLOWING CAUTIONARY
STATEMENTS. WE UNDERTAKE NO OBLIGATION TO RELEASE PUBLICLY THE RESULT OF ANY
REVISION TO THESE FORWARD-LOOKING STATEMENTS THAT MAY BE MADE TO REFLECT EVENTS
OR CIRCUMSTANCES AFTER THE DATE OF THIS PROSPECTUS OR TO REFLECT THE OCCURRENCE
OF UNANTICIPATED EVENTS.

OUR SUBSTANTIAL INDEBTEDNESS COULD ADVERSELY AFFECT OUR FINANCIAL HEALTH AND
  PREVENT US FROM FULFILLING OUR OBLIGATIONS UNDER THE NOTES.

    We have now and, after the exchange offer, will continue to have a
significant amount of indebtedness. The following chart shows important credit
statistics and gives effect to the 1999 acquisitions we completed through April
30, 1999 and the acquisition of Memogarde by Britannia Data Management, our May
1999 public equity offering and the offering of the old Notes as if they had
been completed as of March 31, 1999, and assumes that we had applied the
proceeds from our public equity offering and the offering of the old Notes as
intended:



                                                                           AT MARCH 31, 1999
                                                                          --------------------
                                                                       
Total indebtedness......................................................           604,318
Stockholders' equity....................................................           498,773
Debt to equity ratio....................................................               1.2x


    Our substantial indebtedness could have important consequences to you. For
example, it could:

    - make it more difficult for us to satisfy our obligations with respect to
      the new Notes,

    - make us more sensitive to adverse economic conditions than some of our
      competitors with less debt,

    - limit our ability to fund future working capital, acquisitions, capital
      expenditures and other general corporate requirements,

    - limit our flexibility in planning for, or reacting to, changes in our
      business and the records and information management services industry and

    - make it more difficult for us to obtain additional financing for future
      working capital needs or for possible future acquisitions or other
      purposes, including possible required repurchases of the new Notes.

    See "Description of the New Notes--Repurchase at the Option of
Holders--Change of Control" and "Description of Other Debt--Credit Agreement."

DESPITE CURRENT INDEBTEDNESS LEVELS, WE AND OUR SUBSIDIARIES MAY STILL BE ABLE
  TO INCUR SUBSTANTIALLY MORE DEBT.

    We expect to continue to borrow under our revolving credit facility and
possible future credit arrangements in order to finance future acquisitions and
for general corporate purposes. The terms of

                                       12

the indenture generally do not prohibit us or our subsidiaries from doing so. If
new debt is added to our and our subsidiaries' current debt levels, the related
risks that we and they now face could intensify. Our credit agreement would
permit additional borrowing of up to $250 million as of March 31, 1999, after
giving effect to our 1999 acquisitions completed through April 30, 1999 and the
acquisition of Memogarde by Britannia Data Management, our May 1999 public
equity offering and the offering of the old Notes, and all of those borrowings
would be senior to the new Notes and the subsidiary guarantees. See "Selected
Consolidated Financial and Operating Information" and "Description of Other
Debt--Credit Agreement."

TO SERVICE OUR INDEBTEDNESS, WE WILL REQUIRE A SIGNIFICANT AMOUNT OF CASH. OUR
  ABILITY TO GENERATE CASH DEPENDS ON MANY FACTORS BEYOND OUR CONTROL.

    Our ability to make payments on and to refinance our indebtedness, including
the new Notes, and to fund future acquisitions and capital expenditures will
depend on our ability to generate cash in the future. This, to some extent, is
subject to general economic, financial, competitive, legislative, regulatory and
other factors that are beyond our control. We believe our cash flow from
operations and available borrowings under our existing and future credit
arrangements will be adequate to meet our foreseeable future liquidity needs.

    We cannot assure you, however, that our business will generate sufficient
cash flow from operations, that currently anticipated cost savings will be
realized on schedule or that future borrowings will be available to us under our
existing and future credit arrangements in an amount sufficient to enable us to
pay our indebtedness, including the new Notes, or to fund our other liquidity
needs. We may need to refinance all or a portion of our indebtedness, including
the new Notes, on or before maturity. We cannot assure you that we will be able
to refinance any of our indebtedness, including our revolving credit facility
and the new Notes, on commercially reasonable terms or at all.

YOUR RIGHT TO RECEIVE PAYMENTS ON THESE NOTES IS JUNIOR TO OUR EXISTING SENIOR
  INDEBTEDNESS AND POSSIBLY ALL OF OUR FUTURE BORROWINGS. FURTHER, THE
  GUARANTEES OF THESE NOTES ARE JUNIOR TO ALL OUR GUARANTORS' EXISTING SENIOR
  INDEBTEDNESS AND POSSIBLY TO ALL THEIR FUTURE BORROWINGS. IN SOME SITUATIONS,
  THIS MAY REDUCE OUR ABILITY TO FULFILL OUR FULL OBLIGATIONS UNDER THE NOTES.

    The new Notes and the subsidiary guarantees rank behind all of our and the
subsidiary guarantors' existing senior indebtedness and all of our and their
future borrowings, other than trade payables, except any future indebtedness
that expressly provides that it ranks equal with, or subordinated in right of
payment to, the new Notes and the guarantees. As a result, upon any distribution
to our creditors or the creditors of the guarantors in a bankruptcy, liquidation
or reorganization or similar proceeding relating to us or the guarantors or our
or their property, the holders of our and the guarantors' senior debt will be
entitled to be paid in full in cash before any payment may be made with respect
to the new Notes or the subsidiary guarantees.

    In addition, all payments on the new Notes and the guarantees will be
blocked in the event of a payment default on senior debt and may be blocked for
up to 179 of 360 consecutive days in the event of certain non-payment defaults
on senior debt.

    If we or the guarantors are subject to a bankruptcy, liquidation or
reorganization or similar proceeding, holders of the new Notes will participate
with trade creditors and all other holders of our and the guarantors'
subordinated indebtedness in the assets remaining after we and the subsidiary
guarantors have paid all of the senior debt. However, because the indenture
requires that amounts otherwise payable to holders of the new Notes in a
bankruptcy or similar proceeding be paid to holders of senior debt instead,
holders of the new Notes may receive less, ratably, than holders of trade
payables in any such proceeding. In any of these cases, we and the subsidiary
guarantors may not have

                                       13

sufficient funds to pay all of our creditors and holders of new Notes may
receive less, ratably, than the holders of senior debt.

    Assuming we had completed our acquisitions of First American Records
Management and Data Base and the acquisition of Memogarde by Britannia Data
Management, the offering of the old Notes and our May 1999 public equity
offering on March 31, 1999 and applied the net proceeds from our equity offering
and the offering of the old Notes as intended, the new Notes and the subsidiary
guarantees would have been subordinated to $6.2 million of our and our guarantor
subsidiaries' senior debt and would have ranked equally with $429.9 million of
our and our guarantor subsidiaries' other senior subordinated debt and trade
payables. In addition, approximately $250 million would have been available for
borrowing as additional senior debt under our revolving credit facility. We will
be permitted to incur substantial additional indebtedness, including senior
debt, in the future under the terms of the indenture.

YOUR RIGHT TO RECEIVE PAYMENTS ON THESE NOTES COULD BE ADVERSELY AFFECTED IF ANY
  OF OUR NON-GUARANTOR SUBSIDIARIES DECLARE BANKRUPTCY, LIQUIDATE OR REORGANIZE.

    Most but not all of our subsidiaries will guarantee the new Notes.
Currently, Iron Mountain (Puerto Rico), Inc. and Britannia Data Management and
its subsidiaries are our only operating subsidiaries that will not guarantee the
new Notes. We anticipate that our future international subsidiaries also will
not guarantee the new Notes. In the event of a bankruptcy, liquidation or
reorganization of any of the non-guarantor subsidiaries, holders of their
indebtedness and their trade creditors will generally be entitled to payment of
their claims from the assets of those subsidiaries before any assets are made
available for distribution to us. Assuming Britannia Data Management had
completed the Memogarde acquisition and we had completed the offering of the old
Notes on March 31, 1999, the new Notes would have been effectively junior to
$46.0 million of indebtedness and other liabilities (including trade payables)
of our non-guarantor subsidiaries. Assuming we had completed our 1999
acquisitions through April 30 and the acquisition of Memogarde by Britannia Data
Management on January 1, 1998, the non-guarantor subsidiaries would have
generated 7.3% of our consolidated revenues from continuing operations for the
three months ended March 31, 1999 and held 9.7% of our consolidated assets as of
March 31, 1999.

    Iron Mountain Incorporated is a holding company, and substantially all of
our assets consist of the stock of our subsidiaries. For the year ended December
31, 1998, substantially all of our operations were conducted by our direct and
indirect wholly owned subsidiaries, all of which, other than Arcus Data Security
Limited, were guarantors of our other senior subordinated notes. Arcus Data
Security represented less than 1% of our consolidated revenues for the year
ended December 31, 1998, and was not material to our results of operations. We
do not believe separate financial statements of our subsidiaries are meaningful
or material to investors and we have not included them in this prospectus.
Neither Britannia Data Management and its subsidiaries nor Iron Mountain (Puerto
Rico), Inc. have guaranteed our other senior subordinated notes, including the
old Notes, and initially will not guarantee the new Notes.

WE MAY NOT HAVE THE ABILITY TO RAISE THE FUNDS NECESSARY TO FINANCE THE
  REPURCHASE OF OUTSTANDING SENIOR SUBORDINATED INDEBTEDNESS, INCLUDING THE NEW
  NOTES, UPON A CHANGE OF CONTROL EVENT AS REQUIRED BY THE INDENTURE.

    Upon the occurrence of specific kinds of change of control events, we will
be required to offer to repurchase all outstanding new Notes and our other
existing senior subordinated indebtedness. However, it is possible that we will
not have sufficient funds at the time of the change of control to make the
required repurchase of the new Notes or that restrictions in our revolving
credit facility will not allow such repurchases. In addition, certain important
corporate events, such as leveraged recapitalizations that would increase the
level of our indebtedness, would not constitute a "Change of

                                       14

Control" under the indenture. See "Description of the New Notes--Repurchase at
the Option of Holders--Change of Control."

FEDERAL AND STATE STATUTES COULD ALLOW COURTS, UNDER SPECIFIC CIRCUMSTANCES, TO
  VOID GUARANTEES AND REQUIRE HOLDERS OF THE NOTES TO RETURN PAYMENTS RECEIVED
  FROM GUARANTORS.

    Under federal bankruptcy laws and comparable provisions of state fraudulent
transfer laws, a guarantee could be voided, or claims in respect of a guarantee
could be subordinated to all other debts of that guarantor, if, among other
things, the guarantor, at the time it incurred the indebtedness evidenced by its
guarantee:

    - received less than reasonably equivalent value or fair consideration for
      the incurrence of such guarantee, and

    - was insolvent or rendered insolvent by reason of such incurrence, or

    - was engaged in a business or transaction for which the guarantor's
      remaining assets constituted unreasonably small capital, or

    - intended to incur, or believed that it would incur, debts beyond its
      ability to pay such debts as they mature.

In addition, any payment by that guarantor pursuant to its guarantee could be
voided and required to be returned to the guarantor, or to a fund for the
benefit of the creditors of the guarantor.

    The measures of insolvency for purposes of these fraudulent transfer laws
will vary depending upon the law applied in any proceeding to determine whether
a fraudulent transfer has occurred. Generally, however, a guarantor would be
considered insolvent if:

    - the sum of its debts, including contingent liabilities, were greater than
      the fair saleable value of all of its assets, or

    - if the present fair saleable value of its assets were less than the amount
      that would be required to pay its probable liability on its existing
      debts, including contingent liabilities, as they become absolute and
      mature, or

    - it could not pay its debts as they become due.

    On the basis of historical financial information, recent operating history
and other factors, we believe that each guarantor, after giving effect to its
guarantee of the new Notes, will not be insolvent, will not have unreasonably
small capital for the business in which it is engaged and will not have incurred
debts beyond its ability to pay such debts as they mature. There can be no
assurance, however, as to what standard a court would apply in making such
determinations or that a court would agree with our conclusions in this regard.

    A guarantor may be released from its guarantee at any time upon a sale,
exchange or transfer in compliance with the provisions of the indenture by Iron
Mountain of the capital stock of such guarantor or substantially all of the
assets of such guarantor and, in some other circumstances, a guarantor may be
released from its subsidiary guarantee in connection with our designation of
such guarantor as an unrestricted subsidiary. See "Description of the New
Notes--Certain Covenants-- Additional Subsidiary Guarantees."

SINCE IRON MOUNTAIN IS A HOLDING COMPANY, OUR ABILITY TO MAKE PAYMENTS ON THE
  NEW NOTES DEPENDS IN PART ON THE OPERATIONS OF OUR SUBSIDIARIES.

    Almost all of our tangible assets are held by, and almost all of our
operating revenues are derived from the operating revenues of, our subsidiaries.
As a result, our ability to make payments on the new

                                       15

Notes will be dependent upon the receipt of sufficient funds from our
subsidiaries. However, the new Notes will be guaranteed, on a joint and several
basis, by most, but not all, of our subsidiaries.

BECAUSE OF THE RISKS ASSOCIATED WITH ACQUISITIONS, WE MAY BE UNABLE TO CONTINUE
  OUR GROWTH STRATEGY IN THE FUTURE.

    As part of our growth strategy, we have acquired, and expect to acquire in
the future, records and information management services businesses and
businesses that provide services related to records and information management.
This growth strategy involves certain risks, and we may be unable to pursue such
a strategy in the future. For example, we may be unable to:

    - identify suitable companies to acquire or

    - incur additional debt necessary to acquire such companies, if we are
      unable to pay the purchase price out of working capital or to pay all or
      part of the purchase price with our common stock or other equity
      securities.

    The success of any completed acquisition depends in part on our ability to
integrate effectively the acquired company into us. The process of integrating
the acquired businesses may involve unforeseen difficulties and may require a
disproportionate amount of our management's attention and our financial and
other resources. We may be unable to successfully integrate our recent
acquisitions or future acquisitions.

    The lenders under our revolving credit facility must pre-approve certain
acquisitions. If we propose to acquire one domestic company for a purchase price
over $65 million or if we propose to acquire multiple domestic companies in a
given year and the aggregate purchase price exceeds $150 million in cash and
other consideration or $100 million in cash, or if we propose to invest more
than approximately an additional $30 million in the aggregate internationally,
then lenders holding 51% or more of the commitments under our credit agreement
must approve the acquisition or acquisitions. The lenders could withhold their
consent on acquisitions that we propose to make in excess of such limits.

    Our operating results may fluctuate substantially from quarter to quarter
due to the size, timing and integration of future acquisitions. As a result,
operating results for any quarter may not indicate the results that may be
achieved for any subsequent fiscal quarter or for a full fiscal year.

INTERNATIONAL EXPANSION MAY POSE ADDITIONAL RISKS RESULTING FROM FOREIGN
  REGULATIONS AND MARKETS.

    Our growth strategy involves expanding our operations to international
markets. International operations are subject to numerous additional risks,
including the impact of foreign government regulations, currency fluctuations,
political uncertainties and differences in business practices. We currently
provide records and information management services in the United Kingdom and
France through Britannia Data Management, our majority-owned subsidiary. In
addition, on June 10, 1999, we acquired a records and information services
business in Puerto Rico. Europe and Latin America are our primary areas of focus
for our international expansion at this time, and we are actively pursuing
opportunities in these areas. We intend to use Britannia Data Management as our
primary vehicle for acquisitions in Europe, as was the case with our acquisition
of Memogarde. We can make no assurance that foreign governments will not adopt
regulations or take other actions that would have a direct or indirect adverse
impact on our business or market opportunities within such governments'
countries. Furthermore, we can make no assurance that the political, cultural
and economic climate outside the United States will be favorable to our
operations and growth strategy.

                                       16

WE FACE COMPETITION FOR CUSTOMERS AND ACQUISITION OPPORTUNITIES WHICH COULD
  RESULT IN A DECREASE IN OUR PRICES OR OVERALL GROWTH.

    We compete with one or more records and information management services
providers in all geographic areas where we operate. We believe that competition
for customers is based on price, reputation for reliability, quality of service
and scope and scale of technology and that we generally compete effectively
based on these factors. As a result of this competition, the records and
information management services industry could experience downward pricing
pressures. While we believe that the pricing climate is generally stable, prices
could decline as competitors seek to gain or preserve market share. A downward
trend in pricing, if it continues for an extended period of time, could
materially and adversely affect our results of operations.

    We also compete for companies to acquire. Some of our competitors may
possess greater financial and other resources than we do. If any such competitor
were to devote additional resources to the records and information management
services business and such acquisition candidates, or focused its strategy on
our markets, our results of operations could be adversely affected.

    In addition, we compete with our current and potential customers' internal
records and information management services capabilities. We can provide no
assurance that these organizations will use an outside company such as us for
their future records and information management services. In addition, such
organizations could bring in-house some or all of the functions they currently
outsource to us.

OUR CUSTOMERS MAY SHIFT FROM PAPER STORAGE TO ALTERNATIVE TECHNOLOGIES WHICH
  REQUIRE LESS PHYSICAL SPACE.

    We derive most of our revenues from the storage of paper documents and
related services. This storage requires significant physical space. Alternative
technologies for generating, capturing, managing, transmitting and storing
information exist, many of which require significantly less space than paper.
These technologies include computer media, microform, CD-ROM and optical disk.
To date, none of these technologies has replaced paper as the principal means
for storing information. However, we can provide no assurance that our customers
will continue to store most of their records in paper format. A significant
shift by our customers to storage of data through non-paper based technologies
(whether now existing or developed in the future) could adversely affect our
business.

ALTHOUGH OUR SUCCESS DEPENDS IN PART ON THE PERFORMANCE OF OUR CURRENT EXECUTIVE
  OFFICERS, WE MAY NOT BE ABLE TO RETAIN THEM.

    Our success is partially dependent upon the performance and continued
availability of our current executive officers. We do not have employment
agreements with any of our executive officers. We can provide no assurance that
we will be able to retain our executive officers, the loss of any of whom could
have a material adverse effect on us.

BECAUSE WE OWN OR LEASE PROPERTIES FOR PURPOSES OF STORAGE, UNINSURED LOSSES OR
  DAMAGES TO THE PROPERTIES OR THE RECORDS STORED THEREIN COULD BE DETRIMENTAL
  TO OUR BUSINESS OPERATIONS AND/OR FINANCIAL CONDITION.

    We maintain comprehensive liability, fire, flood, earthquake (where
appropriate) and extended coverage insurance with respect to the properties that
we own or lease, to the extent such insurance is available on commercially
reasonable terms, with customary limits and deductibles. We will continue to
maintain such insurance. We may be unable to obtain full coverage on a
cost-effective basis for some casualties, such as earthquakes, or we may be
unable to obtain any insurance for certain losses, such as losses from riots. In
the past we have suffered damages and losses from an earthquake and a riot in
California, which were substantially covered by insurance.

                                       17

    In March 1997, three fires extensively damaged one and destroyed another of
our records and information management services facilities in South Brunswick
Township, New Jersey. Some of our customers or their insurance carriers have
asserted claims or filed lawsuits against us as a consequence of the destruction
of or damage to their records due to the fires. We cannot predict the outcome of
these claims and proceedings. Based on our present assessment of the situation,
after consultation with our legal counsel, we do not believe that the outcome of
these claims and lawsuits will have a material adverse effect on our financial
condition or results of operations, although we can provide no assurance in this
regard.

    In the future, should uninsured losses or damages occur, we could lose both
our investment in, and anticipated profits and cash flow from, the affected
property and may continue to be obligated on any leasehold obligation, mortgage
indebtedness or other obligations related to such property. Any such loss could
materially adversely affect our financial condition or results of operations.

BECAUSE VARIOUS LAWS MAY IMPOSE LIABILITY ON OWNERS AND OPERATORS OF REAL ESTATE
  FOR A VARIETY OF ENVIRONMENTAL PROBLEMS, REGARDLESS OF FAULT, WE COULD BE
  POTENTIALLY LIABLE FOR ENVIRONMENTAL COSTS ATTRIBUTABLE TO THE PROPERTIES WE
  OWN OR LEASE.

    Various environmental laws impose liability on an owner of real estate for
the costs of investigation and cleanup of soil and groundwater contaminated by
certain hazardous substances or wastes or petroleum products. These laws also
impose liability on lessees conducting operations on contaminated real estate.
Some of these environmental laws impose cleanup liability without regard to
whether the owner or operator of the real estate or operations knew of or was
responsible for the contamination. Moreover, some of these laws impose liability
whether or not operations at the property have been discontinued or title to the
property has been transferred. In addition, the presence of contamination, or
the failure to properly clean up such property, may adversely affect the current
property owner's or operator's ability to sell or rent such property or to
borrow using such property as collateral. Third parties may make claims against
the owner or operator of contaminated real estate based on damages and costs
resulting from off-site migration of the contamination.

    Certain environmental laws also govern the removal, encapsulation or
disturbance of asbestos-containing materials. Such laws may impose liability for
release of asbestos-containing materials and may enable third parties to sue
owners or operators of real estate for personal injury associated with exposure
to such substances. Certain of our facilities contain or may contain
asbestos-containing materials, but we believe that such materials are in
acceptable condition at this time. We believe that future costs related to any
removal or encapsulation of asbestos-containing materials at our facilities will
not be material.

    In addition, certain of our current and former properties that we now or
formerly owned or operated were previously used for industrial or other purposes
that involved the use or storage of hazardous substances or petroleum products
or the generation and disposal of hazardous wastes. In some instances these
properties included the operation of underground storage tanks. Iron Mountain
may be potentially liable for environmental costs such as those discussed above.

    We have from time to time conducted limited environmental investigations and
remedial activities at certain of our former and current facilities, but we have
not undertaken an in-depth environmental review of all of our properties.

    We believe that we are in substantial compliance with all applicable
material environmental laws. Moreover, we are not aware of any material
liability relating to contamination at any of our current or former properties.
We cannot, however, rule out the possibility that environmental conditions for
which we might be liable exist at such properties or at properties which we may
acquire in the future. In addition, future regulatory action and environmental
laws may impose costs for environmental

                                       18

compliance that do not exist today. These future events could have a material
adverse effect on our financial condition and results of operations.

ALTHOUGH WE HAVE IMPLEMENTED A PLAN TO ADDRESS POTENTIAL YEAR 2000 PROBLEMS,
  UNFORESEEN PROBLEMS COULD RESULT IN UNEXPECTED BUSINESS INTERRUPTIONS OR
  COSTS.

    We face risks associated with the fact that many computer systems and
computer software programs were not designed to recognize and process the change
from 1999 to 2000 or may not be able to process dates related to the turn of the
millennium and beyond. These computer systems and software might malfunction or
cease to work unless they are reprogrammed or replaced by the end of 1999. We
have established and are implementing a multi-phase plan in response to the Year
2000, or Y2K, problem. As a result of our plan and other system improvement
initiatives, we are remediating or replacing our financial accounting systems,
information technology staffing operational software and products and services
obtained from third parties. Our primary operational systems for our records and
information management services segment are already Y2K compliant. Although we
do not currently expect the impact of the Year 2000 problem to materially
adversely affect our financial condition or results of operations, we cannot
assure you that we will not experience unexpected difficulties, significant
expenses or business interruptions as a result of the Y2K problem.

NO CURRENT TRADING MARKET FOR THE NEW NOTES EXISTS, AND WE CANNOT GUARANTEE THAT
  A MARKET WILL DEVELOP IN THE FUTURE.

    The new Notes are a new issue of securities for which no trading market
currently exists. We do not intend to list the new Notes on any securities
exchange or to seek approval for quotation through any automated quotation
system. Although the new Notes have been accepted for trading in the Private
Offerings, Resales and Trading through Automated Linkages, or PORTAL, market, we
can give no assurance that an active trading market for the new Notes will
develop on the PORTAL market or elsewhere. We can give no assurance that, even
following the exchange offer, an active trading market for the new Notes will
exist. Even if a market does develop, the liquidity of the trading market in the
new Notes, and the market price quoted for the new Notes, may be adversely
affected by changes in the overall market for high yield securities and by
changes in our financial performance or prospects or in the prospects for
companies in our industry generally.

                                USE OF PROCEEDS

    We will not receive any cash proceeds from the issuance of the new Notes
offered hereby. In consideration for issuing the new Notes as contemplated in
this prospectus, we will receive in exchange old Notes in like principal amount,
the terms of which are substantially identical to the new Notes. The old Notes
surrendered in exchange for new Notes will be retired and canceled and cannot be
reissued. Accordingly, issuance of the new Notes will not result in any increase
in our indebtedness.

    The net proceeds to us from the sale of the old Notes were $145.0 million,
after deducting the discounts to the initial purchasers and estimated offering
expenses, and we used such net proceeds to repay indebtedness under our
revolving credit facility. We used borrowings under our revolving credit
facility during the most recent twelve months to finance acquisitions and for
working capital. Our revolving credit facility has a final maturity date of
September 30, 2002. The weighted average interest rate as of May 7, 1999 on
indebtedness outstanding under our revolving credit facility was 6.25%. As of
June 30, 1999, we had no borrowings outstanding under our revolving credit
facility.

                                       19

                               THE EXCHANGE OFFER

GENERAL

    In connection with the sale of the old Notes, we and our subsidiary
guarantors entered into a registration rights agreement. This agreement requires
us and our subsidiary guarantors to file with the SEC a registration statement
under the Securities Act with respect to an issue of our senior subordinated
notes with terms identical to the old Notes, except with respect to restrictions
on transfer, and to use our best efforts to cause such registration statement to
become effective under the Securities Act by no later than October 23, 1999.
Upon the effectiveness of such registration statement, we will offer to you and
all other holders of the old Notes the opportunity, for a period of 20 business
days, or longer if required by applicable law, from the date the notice of the
exchange offer is mailed to you, to exchange your old Notes for a like principal
amount of new Notes. We are making the exchange offer pursuant to the
registration rights agreement to satisfy our and our subsidiary guarantors'
obligations thereunder.

    Under existing interpretations of the SEC staff enunciated in no-action
letters issued to third parties, unless you are:

    - a broker-dealer that acquired the old Notes directly from us to resell
      pursuant to Rule 144A or any other available exemption under the
      Securities Act or

    - a person that is an affiliate of Iron Mountain within the meaning of Rule
      405 under the Securities Act,

the new Notes would, in general, be freely transferable after the exchange offer
without further registration under the Securities Act by you and without
compliance with the registration and prospectus delivery provisions of the
Securities Act, provided that you acquire the new Notes in the ordinary course
of your business and you have no arrangements with any person to participate in
the distribution of such new Notes. If you are elegible to participate in the
exchange offer and wish to do so, you must represent to us that such conditions
have been met.

    Each broker-dealer that acquired old Notes for its own account as a result
of market-making activities or other trading activities, and that receives new
Notes in exchange for those old Notes, must acknowledge that it will deliver a
prospectus in connection with any resale of such new Notes. The accompanying
letter of transmittal states that by so acknowledging and by delivering a
prospectus, a broker-dealer will not be deemed to admit that it is an
"underwriter" within the meaning of the Securities Act. Delivery of this
prospectus, as it may be amended or supplemented from time to time, will satisfy
a broker-dealer's delivery obligation in connection with such resales of new
Notes. We have agreed to make this prospectus available to any broker-dealer for
use in connection with any such resale for a period of 180 days from the
completion of the exchange offer or such shorter period as will terminate when
all old Notes acquired by broker-dealers for their own accounts as a result of
market-making activities or other trading activities have been exchanged for new
Notes and resold by such broker-dealers. See "Plan of Distribution."

    In the event that:

    - applicable interpretations of the SEC staff do not permit us and our
      subsidiary guarantors to effect such an exchange offer,

    - for any other reason the exchange offer is not completed within 30 days of
      the effective date of the registration statement of which this prospectus
      forms a part, or such longer period as may be required by law or

    - upon the request of an initial purchaser of the old Notes under certain
      circumstances,

                                       20

we and our guarantors will, at our own expense:

    - as promptly as practicable, file a shelf registration statement,

    - use our best efforts to cause such shelf registration statement to be
      declared effective under the Securities Act as promptly as practicable
      after the filing of such shelf registration statement but in no event
      later than 90 days after the occurrence of one of the events described
      above and

    - keep effective such shelf registration statement until the earlier of: (a)
      the second anniversary of the issuance of the old Notes, (b) the sale of
      all of the old Notes under the shelf registration statement, or (c) the
      date on which all non-affiliates may resell the old Notes pursuant to Rule
      144(k) under the Securities Act, or the date on which the old Notes
      otherwise cease to be "Transfer Restricted Securities" (as defined in the
      registration rights agreement).

    Prior to the exchange offer, there has been no public market for the Notes.
We do not intend to list the new Notes on any securities exchange or to seek
approval for quotation through any automated quotation system. We cannot assure
you that an active market for the new Notes will develop. To the extent that a
market for the new Notes develops, the market value of the new Notes will depend
on market conditions (such as yields on alternative investments), general
economic conditions, our financial condition and other conditions. Such
conditions might cause the new Notes, to the extent that they are actively
traded, to trade at a significant discount from the face value. See "Risk
Factors."

    THE EXCHANGE OFFER IS NOT BEING MADE TO, NOR WILL WE ACCEPT SURRENDERS FOR
EXCHANGE FROM, HOLDERS OF OLD NOTES IN ANY JURISDICTION IN WHICH THE EXCHANGE
OFFER OR THE ACCEPTANCE THEREOF WOULD NOT BE IN COMPLIANCE WITH THE SECURITIES
OR BLUE SKY LAWS OF SUCH JURISDICTION.

TERMS OF THE EXCHANGE OFFER

    If you wish to exchange old Notes for new Notes in the exchange offer, you
will be required to make certain representations, including that:

    - you are not an affiliate of Iron Mountain,

    - any new Notes received by you are acquired in the ordinary course of your
      business and

    - at the time of commencement of the exchange offer, you have no arrangement
      with any person to participate in the distribution of the new Notes.

Based on no-action letters issued by the SEC staff to third parties, we believe
that where you can make the above representations, the new Notes issued to you
pursuant to the exchange offer may be offered by you for resale, resold by you
and may otherwise be transferred by you, unless you are an "affiliate" of Iron
Mountain within the meaning of Rule 405 under the Securities Act or a
broker-dealer who purchased old Notes directly from us to resell pursuant to
Rule 144A or any other exemption under the Securities Act, without compliance
with the registration and prospectus delivery requirements of the Securities
Act, provided that you acquire such new Notes in the ordinary course of your
business and you have no arrangement with any person to participate in the
distribution of such new Notes. If you tender your old Notes in the exchange
offer for the purpose of participating in a distribution of the new Notes, you
cannot rely on such interpretation by the SEC staff and must comply with the
registration and prospectus delivery requirements of the Securities Act in
connection with any resale transaction.

    In addition, in connection with any resales of new Notes, any broker-dealer
that acquired old Notes for its own account as a result of market-making
activities or other trading activities must acknowledge that it will deliver a
prospectus meeting the requirements of the Securities Act in connection with any
resale of the new Notes. The SEC has taken the position, in no-action letters
issued to third parties, that such participating broker-dealers may fulfill
their prospectus delivery

                                       21

requirements with respect to the new Notes, other than for a resale of an unsold
allotment from the original sales of old Notes, with this prospectus. Under the
registration rights agreement, we and our subsidiary guarantors agreed that for
a period of 180 days following completion of the exchange offer, we would make
this prospectus available to participating broker-dealers, and other persons, if
any, subject to similar prospectus delivery requirements, to use in connection
with the resale of such new Notes.

    If we experience a default due to:

    - the registration statement of which this prospectus forms a part not being
      declared effective by the SEC on or before October 23, 1999,

    - our and our subsidiary guarantors failing to complete the exchange offer
      on or before the 30th day after the effective date of the registration
      statement, or such longer time as may be required by applicable law, or

    - either the registration statement or the shelf registration statement
      being declared effective but thereafter ceasing to be effective in
      connection with resales of Notes during the period specified in the
      registration rights agreement,

then we will pay to you liquidated damages, accruing from the date of the first
such event of default, or if such event of default has been cured, from the date
of the next event of default, in an amount equal to 0.25% per annum of the
principal amount of the Notes held by you during the first 90-day period after
such event of default. The amount of the liquidated damages will increase, up to
a maximum rate of 2.0% per annum, by an additional 0.25% per annum with respect
to each subsequent 90-day period during the continuance of an event of default.
We will pay any liquidated damages accrued as of any interest payment date on
such date. Following the cure of all such events of default, the accrual of
liquidated damages will cease.

    If we complete the exchange offer in accordance with the provisions of the
registration rights agreement described above, we will not be required to file a
shelf registration statement to register any outstanding old Notes, and the
interest rate on such old Notes will remain at its initial level of 8 1/4% per
annum. The exchange offer will be completed upon our having exchanged, pursuant
to the exchange offer, new Notes for all old Notes that have been properly
tendered and not withdrawn by the expiration date. In such event, if you do not
participate in the exchange offer and are seeking liquidity in your investment,
you would have to rely on exemptions to registration requirements under the
securities laws, including the Securities Act.

    Upon the terms and subject to the conditions set forth in this prospectus
and in the accompanying letter of transmittal, we will accept all old Notes
validly tendered prior to 5:00 p.m., New York City time, on the expiration date.
We will issue $1,000 in principal amount of new Notes and integral multiples in
excess thereof in exchange for an equal principal amount of outstanding old
Notes tendered and accepted in the exchange offer. You may tender some or all of
your old Notes pursuant to the exchange offer in any denomination of $1,000 or
in integral multiples in excess thereof.

    The form and terms of the new Notes will be the same as the form and terms
of the old Notes except that the new Notes will not bear legends restricting the
transfer thereof. The new Notes will evidence the same debt as the old Notes.
The new Notes will be issued under and entitled to the benefits of the
indenture.

    As of the date of this prospectus, $150,000,000 million aggregate principal
amount of the old Notes are outstanding and CEDE & Co., the nominee of the
Depository Trust Company, or DTC, is the only registered holder thereof. In
connection with the issuance of the old Notes, we arranged for the old Notes to
be eligible for trading in the PORTAL Market, the National Association of
Securities Dealers' screen based, automated market trading of securities
eligible for resale under Rule 144A, and to be

                                       22

issued and transferable in book-entry form through the facilities of DTC. The
new Notes will also be issuable and transferable in book-entry form through DTC.

    The old Notes, whether sold in offshore transactions in reliance on
Regulation S under the Securities Act or in the United States in reliance on
Rule 144A under the Securities Act, were initially represented by a single,
permanent global note, which was deposited with the trustee, as custodian for
DTC, and registered in the name of CEDE & Co., DTC's nominee, for credit to an
account of a direct or indirect participant in DTC, including Morgan Guaranty
Trust Company of New York, Brussels Office, as operator of the Euroclear System,
and Citibank, N.A., as depositary for Cedel Bank, societe anonyme. The new Notes
exchanged for the old Notes that are represented by the global note will
continue to be represented by a permanent global note in definitive, fully
registered form, registered in the name of a nominee of DTC and deposited with
the trustee as custodian, unless the beneficial holders thereof request
otherwise. See "Description of the New Notes--Book-Entry, Delivery and Form."
Notes may be tendered only in denominations of $1,000 and integral multiples in
excess thereof.

    This prospectus, together with the accompanying letter of transmittal, is
being sent to all registered holders as of             , 1999.

    We will be deemed to have accepted validly tendered old Notes when, as and
if we have given oral or written notice thereof to our exchange agent. See
"--Exchange Agent." The exchange agent will act as agent for the tendering
holders of old Notes for the purpose of receiving new Notes from us and
delivering new Notes to such holders.

    If old Notes you tender are not accepted for exchange because of an invalid
tender or the occurrence of certain other events set forth herein, any such
unaccepted old Notes will be returned, without expense, to you as promptly as
practicable after the expiration date of the exchange offer.

    If you tender your old Notes in the exchange offer, you will not be required
to pay brokerage commissions or fees or, subject to the instructions in the
letter of transmittal, transfer taxes with respect to the exchange of old Notes
pursuant to the exchange offer. We will pay all charges and expenses, other than
particular applicable taxes, in connection with the exchange offer. See "--Fees
and Expenses."

    You do not have any appraisal or dissenters' rights under the Delaware
General Corporation Law or the indenture in connection with the exchange offer.
We intend to conduct the exchange offer in accordance with the provisions of the
registration rights agreement and the applicable requirements of the Exchange
Act and the rules and regulations of the SEC thereunder. If you do not tender
your old Notes for exchange in the exchange offer, they will remain outstanding
and continue to accrue interest, but will not be entitled to any rights or
benefits under the registration rights agreement.

EXPIRATION DATE; EXTENSIONS; AMENDMENTS

    The term "expiration date" will mean 5:00 p.m. New York City time, on
            , 1999, unless we, in our sole discretion, extend the exchange
offer, in which case the term "expiration date" will mean the latest date to
which the exchange offer is extended.

    In order to extend the expiration date, we will notify our exchange agent of
any extension by oral or written notice and will mail to the record holders of
old Notes an announcement thereof, each prior to 9:00 a.m., New York City time,
on the next business day after the previously scheduled expiration date. Such
announcement may state that we are extending the exchange offer for a specified
period of time.

    We reserve the right (a) to delay acceptance of any old Notes, to extend the
exchange offer or to terminate the exchange offer and to refuse to accept old
Notes not previously accepted, if any of the

                                       23

conditions set forth herein under "Termination" have occurred and have been
waived by us, if permitted to be waived by us, by giving oral or written notice
of such delay, extension or termination to our exchange agent, and (b) to amend
the terms of the exchange offer in any manner deemed by us to be advantageous to
the holders of the old Notes. Any such delay in acceptance, extension,
termination or amendment will be followed as promptly as practicable by oral or
written notice thereof. If we amend the exchange offer in a way that we
determine constitutes a material change, we will promptly disclose such
amendment in a manner reasonably calculated to inform the holders of the old
Notes of such amendment.

    Without limiting the manner in which we may choose to make public
announcements of any delay in acceptance, extension, termination or amendment of
the exchange offer, we will have no obligation to publish, advertise or
otherwise communicate any such public announcement, other than by making a
timely release to the Dow Jones News Service.

INTEREST ON THE NEW NOTES

    We will pay interest on the new Notes semi-annually in arrears on January 1
and July 1 of each year, commencing January 1, 2000, to holders of record on the
immediately preceding June 15 and December 15. The new Notes will bear interest
from the last interest payment date on which interest was paid on the old Notes.
We will pay such interest with the first interest payment on the new Notes.
Interest on the old Notes accepted for exchange will cease to accrue upon
issuance of the new Notes. Old Notes that you do not exchange for new Notes
pursuant to the exchange offer will remain outstanding and continue to bear
interest at a rate of 8 1/4% per annum after the expiration date of the exchange
offer.

PROCEDURES FOR TENDERING

    To tender in the exchange offer, you must:

    - complete, sign and date the letter of transmittal, or a facsimile thereof,

    - have the signatures thereon guaranteed if required by the letter of
      transmittal, and

    - mail or otherwise deliver such letter of transmittal or such facsimile,
      together with your old Notes, unless the book-entry transfer procedures
      described below are used, and any other required documents, to our
      exchange agent for receipt,

all prior to 5:00 p.m., New York City time, on the expiration date.

    Any financial institution that is a participant in DTC's Book-Entry Transfer
Facility system may make book-entry delivery of the old Notes by causing DTC to
transfer such old Notes into our exchange agent's account in accordance with
DTC's procedure for such transfer. Although delivery of old Notes may be
effected through book-entry transfer into our exchange agent's account at DTC,
the letter of transmittal or facsimile thereof, with any required signature
guarantees and any other required documents, must, in any case, be transmitted
to and received or confirmed by our exchange agent at its addresses set forth in
this prospectus prior to 5:00 p.m., New York City time, on the expiration date.
DELIVERY OF DOCUMENTS TO DTC IN ACCORDANCE WITH ITS PROCEDURES DOES NOT
CONSTITUTE DELIVERY TO OUR EXCHANGE AGENT.

    Your tender of old Notes will constitute an agreement between you and us in
accordance with the terms and subject to the conditions set forth herein and in
your letter of transmittal.

    You must deliver all documents to our exchange agent at its address set
forth herein. You may also request that your broker, dealer, commercial bank,
trust company or nominee effect such tender for you.

                                       24

    The method of delivery of old Notes and the letter of transmittal and all
other required documents to our exchange agent is at your election and risk.
Instead of delivery by mail, we recommend that you use an overnight or hand
delivery service. In all cases, you should allow sufficient time to assure
timely delivery. You should not send any letter of transmittal or old Notes to
us.

    Only a holder of old Notes may tender such old Notes in the exchange offer.
The term "holder" with respect to the exchange offer means any person in whose
name old Notes are registered on our books or the books of any other person who
has obtained a properly completed bond power from the registered holder or any
person whose old Notes are held of record by DTC who desires to deliver such old
Notes by book-entry transfer at DTC.

    If you are a beneficial holder whose old Notes are registered in the name of
your broker, dealer, commercial bank, trust company or other nominee and you
wish to tender, you should contact such registered holder promptly and instruct
such registered holder to tender on your behalf. If you wish to tender on your
own behalf, you must, prior to completing and executing the letter of
transmittal and delivering your old Notes, either make appropriate arrangements
to register ownership of the old Notes in your name or obtain a properly
completed bond power from the registered holder. The transfer of record
ownership may take considerable time.

    Signatures on a letter of transmittal or a notice of withdrawal, as the case
may be, must be guaranteed by a member firm of a registered national securities
exchange or of the National Association of Securities Dealers, Inc., a
commercial bank or trust company having an office or correspondent in the United
States or an "eligible guarantor institution" within the meaning of Rule 17Ad-15
under the Exchange Act that is a participant in a recognized medallion signature
guarantee program, unless the old Notes tendered pursuant thereto are tendered
(a) by a registered holder who has not completed the box entitled "Special
Issuance Instructions" or "Special Delivery Instructions" on the letter of
transmittal or (b) for the account of an eligible institution.

    If the letter of transmittal is signed by a person other than the registered
holder of any old Notes listed therein, such old Notes must be endorsed or
accompanied by appropriate bond powers which authorize such person to tender the
old Notes on behalf of the registered holder, in either case signed as the name
of the registered holder or holders appears on the old Notes.

    If you sign the letter of transmittal or any old Notes or bond powers as a
trustee, executor, administrator, guardian, attorney-in-fact, officer of a
corporation or in any other fiduciary or representative capacity, you should so
indicate when signing, and unless waived by us, submit evidence satisfactory to
us of your authority to so act with the letter of transmittal.

    All questions as to the validity, form, eligibility, including time of
receipt, acceptance and withdrawal of the tendered old Notes will be determined
by us in our sole discretion, which determination will be final and binding. We
reserve the absolute right to reject any and all old Notes not properly tendered
or any old Notes our acceptance of which would, in the opinion of our counsel,
be unlawful. We also reserve the absolute right to waive any irregularities or
conditions of tender as to particular old Notes. Our interpretation of the terms
and conditions of the exchange offer, including the instructions in the letter
of transmittal, will be final and binding on all parties. Unless waived, you
must cure any defects or irregularities in connection with your tender of old
Notes within such time as we determine. Neither Iron Mountain, our exchange
agent nor any other person will be under any duty to give notification of
defects or irregularities with respect to tenders of old Notes, nor will any of
us or them incur any liability for failure to give such notification. Tenders of
old Notes will not be deemed completed until such irregularities have been cured
or waived. Any old Notes received by the exchange agent that you have not
properly tendered, and as to which the defects or irregularities have not been
cured or waived, will be returned to you without cost by the exchange agent,
unless otherwise provided in the letter of transmittal, as soon as practicable
following the expiration date.

                                       25

    In addition, we reserve the right in our sole discretion to (a) purchase or
make offers for any old Notes that remain outstanding subsequent to the
expiration date, or, as set forth under "Termination," to terminate the exchange
offer and (b) to the extent permitted by applicable law, purchase old Notes in
the open market, in privately negotiated transactions or otherwise. The terms of
any such purchases or offers may differ from the terms of the exchange offer.

GUARANTEED DELIVERY PROCEDURES

    If you wish to tender your old Notes and (a) your old Notes are not
immediately available or (b) you cannot deliver your old Notes, the letter of
transmittal or any other required documents to our exchange agent prior to the
expiration date, or (c) if you cannot complete the procedure for book-entry
transfer on a timely basis, you may effect a tender if:

    (1) the tender is made through an eligible guarantor institution,

    (2) prior to the expiration date, our exchange agent receives from such
        eligible guarantor institution a properly completed and duly executed
        Notice of Guaranteed Delivery by facsimile transmission, mail or hand
        delivery setting forth your name and address, the certificate number or
        numbers of such old Notes and the principal amount of old Notes
        tendered, stating that the tender is being made thereby, and
        guaranteeing that, within three business days after the expiration date,
        the letter of transmittal or facsimile thereof, together with the
        certificate(s) representing the old Notes, unless the book-entry
        transfer procedures will be used, to be tendered in proper form for
        transfer and any other documents required by the letter of transmittal,
        will be deposited by the eligible guarantor institution with our
        exchange agent and

    (3) such properly completed and executed letter of transmittal or facsimile
        thereof, together with the certificate(s) representing all tendered old
        Notes in proper form for transfer, or confirmation of a book-entry
        transfer into our exchange agent's account at DTC of old Notes delivered
        electronically, and all other documents required by the letter of
        transmittal are received by our exchange agent within three business
        days after the expiration date.

    Upon request to our exchange agent, a Notice of Guaranteed Delivery will be
sent to you, if you wish to tender your old Notes according to the guaranteed
delivery procedures set forth above.

WITHDRAWAL OF TENDERS

    Except as otherwise provided herein, you may withdraw your tender of old
Notes at any time prior to 5:00 p.m., New York City time, on the expiration date
of the exchange offer.

    To withdraw a tender of old Notes in the exchange offer, our exchange agent
must receive a written or facsimile transmission notice of withdrawal at its
address set forth herein prior to 5:00 p.m., New York City time, on the
expiration date. Any such notice of withdrawal must:

    - specify the name of the person having deposited the old Notes to be
      withdrawn,

    - identify the old Notes to be withdrawn, including the certificate number
      or numbers and principal amount of such old Notes,

    - be signed by the depositor of such old Notes in the same manner as the
      original signature on the letter of transmittal by which such old Notes
      were tendered, including any required signature guarantees, or be
      accompanied by documents of transfer sufficient to permit the trustee with
      respect to the old Notes to register the transfer of such old Notes into
      the name of the depositor withdrawing the tender and

                                       26

    - specify the name in which any such old Notes are to be registered, if
      different from that of the depositor.

    We will determine all questions as to the validity, form and eligibility,
including time of receipt, of such withdrawal notices and our determination will
be final and binding on all parties. Any old Notes so withdrawn will be deemed
not to have been validly tendered for purposes of the exchange offer, and no new
Notes will be issued with respect thereto unless the old Notes so withdrawn are
validly retendered. We will return any old Notes that you tender but that we do
not accept for exchange, without cost to you, as soon as practicable after
withdrawal, rejection of tender or termination of the exchange offer. Properly
withdrawn old Notes may be retendered by following one of the procedures
described above under "Procedures for Tendering" at any time prior to the
expiration date.

TERMINATION

    Notwithstanding any other term of the exchange offer, we will not be
required to accept old Notes for exchange, or exchange new Notes for any old
Notes not theretofore accepted for exchange, and may terminate or amend the
exchange offer as provided herein before the acceptance of such old Notes if:

    - any action or proceeding is instituted or threatened in any court or by or
      before any governmental agency with respect to the exchange offer which,
      in our judgment, might materially impair our ability to proceed with the
      exchange offer or

    - any law, statute, rule or regulation is proposed, adopted or enacted, or
      any existing law, statute, rule or regulation is interpreted by the SEC
      staff in a manner which, in our judgment, might materially impair our
      ability to proceed with the exchange offer.

    If we determine that we may terminate the exchange offer, as set forth
above, we may:

    - refuse to accept any old Notes and return to you any old Notes that you
      have tendered,

    - extend the exchange offer and retain all old Notes tendered prior to the
      expiration of the exchange offer, subject to your right to withdraw your
      tendered old Notes, or

    - waive such termination event with respect to the exchange offer and accept
      all properly tendered old Notes that have not been withdrawn.

    If our waiver of such termination event constitutes a material change in the
exchange offer, we will disclose such change by means of a supplement to this
prospectus that will be distributed to each registered holder of old Notes, and,
if the exchange offer would otherwise expire during such period, we will extend
the exchange offer for a period of five to ten business days, depending upon the
significance of the waiver and the manner of disclosure to the registered
holders of the old Notes.

EXCHANGE AGENT

    The Bank of New York has been appointed as exchange agent for the exchange
offer. You should direct questions and requests for assistance and requests for
additional copies of this prospectus or of the letter of transmittal to our
exchange agent addressed as follows:

                        BY REGISTERED OR CERTIFIED MAIL:

                              The Bank of New York
                             101 Barclay Street-7E
                            New York, New York 10286
                           Attention: Noriko Miyazaki
                             Reorganization Section

                                       27

                         BY HAND OR OVERNIGHT DELIVERY:

                              The Bank of New York
                               101 Barclay Street
                        Corporate Trust Services Window
                                  Ground Level
                            New York, New York 10286
                           Attention: Noriko Miyazaki
                             Reorganization Section

                    BY FACSIMILE FOR ELIGIBLE INSTITUTIONS:
                                 (212) 815-6339

FEES AND EXPENSES

    We will bear the expenses of soliciting tenders pursuant to the exchange
offer. We are making the principal solicitation for tenders pursuant to the
exchange offer by mail. Additional solicitations may be made by our officers and
regular employees and our affiliates in person, by telegraph or by telephone.

    We will not make any payments to brokers, dealers or other persons
soliciting acceptances of the exchange offer. We will, however, pay our exchange
agent reasonable and customary fees for its services and will reimburse our
exchange agent for its reasonable out-of-pocket expenses in connection
therewith. We may also pay brokerage houses and other custodians, nominees and
fiduciaries the reasonable out-of-pocket expenses incurred by them in forwarding
copies of this prospectus, letters of transmittal and related documents to the
beneficial owners of the old Notes and in handling or forwarding tenders for
exchange.

    We will pay the expenses to be incurred in connection with the exchange
offer, including fees and expenses of our exchange agent and trustee and
accounting and legal fees.

    We will pay all transfer taxes, if any, applicable to the exchange of old
Notes pursuant to the exchange offer. If, however, certificates representing new
Notes issued in exchange for old Notes, or old Notes not tendered or accepted
for exchange, are to be delivered to, or are to be registered or issued in the
name of, any person other than the registered holder of the old Notes tendered,
or if tendered old Notes are registered in the name of any person other than the
person signing the letter of transmittal, or if a transfer tax is imposed for
any reason other than the exchange of old Notes pursuant to the exchange offer,
then the amount of any such transfer taxes, whether imposed on the registered
holder or any other persons, will be payable by the tendering holder. If
satisfactory evidence of payment of such taxes or exemption therefrom is not
submitted with the letter of transmittal, the amount of such transfer taxes will
be billed directly to such tendering holder.

ACCOUNTING TREATMENT

    We will record the new Notes at the same carrying value as the old Notes, as
reflected in our accounting records on the date of the exchange. Accordingly, we
will not recognize any gain or loss for accounting purposes upon the completion
of the exchange offer. We will amortize the expenses of the exchange offer over
the term of the new Notes under generally accepted accounting principles.

                                       28

           SELECTED CONSOLIDATED FINANCIAL AND OPERATING INFORMATION

                     (IN THOUSANDS, EXCEPT PER SHARE DATA)

    The following selected consolidated statements of operations and balance
sheet data of Iron Mountain as of and for each of the years ended December 31,
1994, 1995, 1996, 1997 and 1998 is derived from Iron Mountain's audited
consolidated financial statements. The selected consolidated statements of
operations and balance sheet data of Iron Mountain for the three months ended
March 31, 1998 and 1999 have been derived from our unaudited condensed
consolidated financial statements. You should read this information in
conjunction with "Management's Discussion and Analysis of Financial Condition
and Results of Operations" and with Iron Mountain's Consolidated Financial
Statements and the footnotes thereto incorporated by reference in this
prospectus. See "Incorporation of Certain Information by Reference."



                                                                                                                 THREE MONTHS
                                                                     YEAR ENDED DECEMBER 31,                   ENDED MARCH 31,
                                                      -----------------------------------------------------  --------------------
                                                                                                   
                                                        1994       1995       1996       1997       1998       1998       1999
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
CONSOLIDATED STATEMENTS OF OPERATIONS DATA:
Revenues:
  Storage...........................................  $  54,098  $  64,165  $  85,826  $ 125,968  $ 230,702  $  52,948  $  67,722
  Service and Storage Material Sales................     33,520     40,271     52,892     82,797    153,259     36,108     41,649
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
    Total Revenues..................................     87,618    104,436    138,718    208,765    383,961     89,056    109,371
Operating Expenses:
  Cost of Sales (Excluding Depreciation)............     45,880     52,277     70,747    106,879    192,113     44,917     54,435
  Selling, General and Administrative...............     20,853     26,035     34,342     51,668     95,867     22,360     27,875
  Depreciation and Amortization.....................      8,690     12,341     16,936     27,107     48,301     11,058     13,595
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
    Total Operating Expenses........................     75,423     90,653    122,025    185,654    336,281     78,335     95,905
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
Operating Income....................................     12,195     13,783     16,693     23,111     47,680     10,721     13,466
Interest Expense, Net...............................      8,954     11,838     14,901     27,712     45,673     12,314     11,944
Other Income, Net(1)................................         --         --         --         --      1,384         --         --
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
Income (Loss) from Continuing Operations Before
  Provision (Benefit) for Income Taxes and Minority
  Interest..........................................      3,241      1,945      1,792     (4,601)     3,391     (1,593)     1,522
Provision (Benefit) for Income Taxes................      1,957      1,697      1,435        (80)     6,558     (1,045)     1,623
Minority Interest in Net Income of Consolidated
  Subsidiaries......................................         --         --         --         --         --         --        147
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
Income (Loss) from Continuing Operations............      1,284        248        357     (4,521)    (3,167)      (548)      (248)
Income from Discontinued Operations (net of tax
  provision)........................................         --         --         --         --        201        234         99
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
Income (Loss) Before Extraordinary Charge...........      1,284        248        357     (4,521)    (2,966)      (314)      (149)
Extraordinary Charge, Net of Tax Benefit(2).........         --         --      2,126         --         --         --         --
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
Net Income (Loss)...................................      1,284        248     (1,769)    (4,521)    (2,966)      (314)      (149)
Accretion of Redeemable Put Warrant.................      1,412      2,107        280         --         --         --         --
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
Net Loss Applicable to Common Stockholders..........  $    (128) $  (1,859) $  (2,049) $  (4,521) $  (2,966) $    (314) $    (149)
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
Income (Loss) Per Common Share--Basic and Diluted:
  Income (Loss) from Continuing Operations..........  $   (0.40) $  (32.61) $    0.00  $   (0.26) $   (0.12) $   (0.02) $   (0.01)
  Income from Discontinued Operations...............         --         --         --         --       0.01       0.01         --
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
  Income (Loss) Before Extraordinary Charge.........      (0.40)    (32.61)      0.00      (0.26)     (0.11)     (0.01)     (0.01)
  Extraordinary Charge, Net of Tax Benefit(2).......         --         --      (0.15)        --         --         --         --
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
  Net Loss Applicable to Common Stockholders........  $   (0.40) $  (32.61) $   (0.15) $   (0.26) $   (0.11) $   (0.01) $   (0.01)
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
  Weighted Average Common Shares Outstanding........        321         57     13,911     17,172     27,470     22,269     29,500
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
  Pro Forma(3):
    Net Loss Per Share Applicable to Common
      Stockholders..................................  $   (0.01) $   (0.16) $   (0.13) $   (0.26) $   (0.11) $   (0.01) $   (0.01)
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
    Weighted Average Common Shares Outstanding......     11,976     11,676     15,206     17,172     27,470     22,269     29,500
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
OTHER DATA:
EBITDA from Continuing Operations(4)................  $  20,885  $  26,124  $  33,629  $  50,218  $  95,981  $  21,779  $  27,061
EBITDA from Continuing Operations as a Percentage of
  Total Revenues....................................       23.8%      25.0%      24.2%      24.1%      25.0%      24.5%      24.7%
Capital Expenditures:
  Growth(5)(6)......................................  $  15,829  $  14,395  $  23,334  $  37,082  $  54,039  $   9,545  $  17,642
  Maintenance(7)....................................      1,151        858      1,112      1,238      1,888        576        651
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
    Total Capital Expenditures(6)...................  $  16,980  $  15,253  $  24,446  $  38,320  $  55,927  $  10,121  $  18,293
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------


                                       29

           SELECTED CONSOLIDATED FINANCIAL AND OPERATING INFORMATION

                     (IN THOUSANDS, EXCEPT PER SHARE DATA)



                                                                                                                 THREE MONTHS
                                                                       AS OF DECEMBER 31,                      ENDED MARCH 31,
                                                      -----------------------------------------------------  --------------------
                                                                                                   
                                                        1994       1995       1996       1997       1998       1998       1999
                                                      ---------  ---------  ---------  ---------  ---------  ---------  ---------
CONSOLIDATED BALANCE SHEET DATA:
Cash and Cash Equivalents...........................  $   1,303  $   1,585  $   3,453  $  24,510  $   1,715  $   2,312  $   4,899
Total Assets........................................    136,859    186,881    281,799    636,786    967,385    806,018  1,052,744
Total Debt..........................................     86,258    121,874    184,733    428,018    456,178    523,154    541,315
Stockholders' Equity................................     22,869     21,011     52,384    137,733    338,882    193,549    338,857


- ------------------------

(1) Other income, net includes a $1.7 million gain resulting from the settlement
    of several insurance claims related to the March 1997 fires at our South
    Brunswick Township, New Jersey facilities.

(2) The extraordinary charge consists of a prepayment penalty, the write-off of
    deferred financing costs, original issue discount and loss on termination of
    interest rate protection agreements.

(3) Represents pro forma earnings per share as if the preferred stock that was
    converted into common stock in connection with our initial public offering
    completed in 1996 had been converted for all periods presented.

(4) Based on our experience in the records and information management services
    industry, we believe that EBITDA is an important tool for measuring the
    performance of records and information management services companies
    (including potential acquisition targets) in several areas, such as
    liquidity, operating performance and leverage. In addition, lenders use
    EBITDA in evaluating records and information management services companies,
    and substantially all of our financing agreements contain covenants in which
    EBITDA is used as a measure of financial performance. However, you should
    not consider EBITDA to be a substitute to operating or net income (as
    determined in accordance with GAAP) as an indicator of our performance or to
    cash flow from operations (as determined in accordance with GAAP) as a
    measure of liquidity.

(5) Growth capital expenditures consist primarily of investments in racking
    systems, management information systems, new buildings and expansion of
    storage capacity in existing facilities.

(6) Includes $2,901 in 1994 related to the cost of constructing a records and
    information management services facility which was sold in a sale and
    leaseback transaction in 1994.

(7) Consists of capital expenditures we made in order to maintain our current
    revenues.

                                       30

                           DESCRIPTION OF OTHER DEBT

OTHER SENIOR SUBORDINATED DEBT

    We have outstanding $165.0 million in principal amount of 10 1/8% Senior
Subordinated Notes due 2006 and $250.0 million in principal amount of 8 3/4%
Senior Subordinated Notes due 2009. The new Notes will rank equally with the
10 1/8% Notes and the 8 3/4% Notes. The 10 1/8% Notes mature on October 1, 2006,
and bear interest at 10 1/8% per annum, payable semi-annually in arrears on
April 1 and October 1. The 8 3/4% Notes mature on September 30, 2009, and bear
interest at 8 3/4% per annum, payable semi-annually in arrears on March 31 and
September 30. We may redeem up to 35% of the initial principal amount of each of
the 10 1/8% Notes and the 8 3/4% Notes with the net proceeds of certain public
offerings of our equity at a redemption price of 109.125% of the aggregate
principal amount in the case of the 10 1/8% Notes and at a redemption price of
108.75% of the aggregate principal amount in the case of the 8 3/4% Notes, in
each case plus accrued and unpaid interest. Like the Notes, the 10 1/8% Notes
and the 8 3/4% Notes are general unsecured obligations of Iron Mountain,
subordinated in right of payment to our senior indebtedness. The Notes will be
guaranteed equally with the 10 1/8% Notes and the 8 3/4% Notes, on an unsecured
senior subordinated and joint and several basis, by most, but not all, of our
present and future subsidiaries.

CREDIT AGREEMENT

    Our credit agreement is a $250.0 million revolving credit facility that
matures on September 30, 2002. Upon maturity, all outstanding revolving credit
loans and other amounts payable under the credit agreement will become due.

    We may borrow money under the credit agreement to finance possible future
acquisitions, as well as for working capital and general corporate purposes. Our
obligations under the credit agreement are guaranteed by substantially all of
our domestic subsidiaries and are secured by the pledge of the stock of such
subsidiaries. We must apply all or a portion of the proceeds of certain
insurance payments, condemnations, issuances of indebtedness and asset
dispositions to prepay outstanding borrowings under the credit agreement.

    We have the right to elect various interest rates on our outstanding
borrowings under the credit agreement. The interest rate will be based upon the
applicable reference rate and a margin or spread over such reference rate. The
spread varies based upon the ratio of our indebtedness to our EBITDA. We have
the option of causing the reference rate to be based upon (1) the greater of (a)
the agent's prime rate, (b) a rate based upon the rate for certificates of
deposit or (c) a rate based upon the overnight federal funds rate, or (2) for
periods of up to 12 months, the interest rates prevailing on the date of
determination in the London interbank markets.

    Both our credit agreement and the indentures relating to the 10 1/8% Notes
and the 8 3/4% Notes contain customary events of default and covenants
restricting our ability to, among other things:

    - declare dividends or redeem or repurchase capital stock,

    - make optional payments and modifications of subordinated and other debt
      instruments,

    - incur liens and engage in sale and leaseback transactions,

    - make loans and investments,

    - incur indebtedness and contingent obligations,

    - make capital expenditures,

    - engage in mergers, acquisitions and asset sales,

    - enter into transactions with affiliates and

    - make changes in their lines of business.

                                       31

We are also required by our credit agreement to comply with financial covenants
with respect to (a) a maximum leverage ratio, (b) a minimum interest coverage
ratio and (c) a minimum fixed charge coverage ratio. In addition, the lenders
under our credit agreement must pre-approve certain acquisitions. If we propose
to acquire one domestic company for a purchase price over $65.0 million or if we
propose to acquire multiple domestic companies in a given year and the aggregate
purchase price exceeds $150.0 million in cash and other consideration or $100.0
million in cash, or if we propose to invest more than approximately an
additional $30 million in the aggregate internationally, then lenders holding
51% or more of the commitments under our credit agreement must approve the
acquisition or acquisitions. The lenders could withhold their consent on
acquisitions that we propose to make in excess of such limits.

                                       32

                          DESCRIPTION OF THE NEW NOTES

    You can find the definitions of certain terms used in this description under
the subheading "Certain Definitions." In this description, the word "Company"
refers only to Iron Mountain and not to any of its Subsidiaries.

    The Company will issue the new Notes under the Indenture (the "Indenture")
among the Company, the subsidiary guarantors (the "Guarantors") and The Bank of
New York, as Trustee (the "Trustee"). The terms of the new Notes include those
stated in the Indenture and those made part of the Indenture by reference to the
Trust Indenture Act of 1939, as amended (the "Trust Indenture Act"). A copy of
the Indenture may be obtained from the Company or the Initial Purchasers. The
Trustee is also a lead manager and a lender under our revolving credit agreement
and received a portion of the amount repaid under the credit agreement with the
net proceeds from the offering of the old Notes. The Trustee also serves as
trustee with respect to our 8 3/4% Senior Subordinated Notes due 2009.

    The following description is a summary of the material provisions of the
Indenture. It does not restate the Indenture in its entirety. We urge you to
read the Indenture because it, and not this description, defines your rights as
a holder of the Notes ("Holder"). Certain defined terms used in this description
but not defined below under "--Certain Definitions" have the meanings assigned
to them in the Indenture.

BRIEF DESCRIPTION OF THE NOTES AND THE GUARANTEES

  THE NOTES

    The Notes:

       - are general unsecured obligations of the Company,

       - are subordinated in right of payment to all existing and future Senior
         Debt of the Company,

       - are PARI PASSU in right of payment with any future senior subordinated
         Indebtedness of the Company and

       - are unconditionally guaranteed by the Guarantors.

  THE GUARANTEES

    The Notes are guaranteed by the Guarantors.

    Each Guarantee of the Notes:

       - is a general unsecured obligation of the Guarantor,

       - is subordinated in right of payment to all existing and future Senior
         Debt of the Guarantor and

       - is PARI PASSU in right of payment with any future senior subordinated
         Indebtedness of the Guarantor.

    Not all of our Subsidiaries will guarantee the Notes. In the event of a
bankruptcy, liquidation or reorganization of any of these non-guarantor
Subsidiaries, these non-guarantor Subsidiaries will pay the holders of their
debts and their trade creditors before they will be able to distribute any of
their assets to us. Iron Mountain (Puerto Rico), Inc. and Britannia Data
Management and its subsidiaries are our only operating Subsidiaries that
initially will not be Guarantors. Assuming we had completed our 1998 and 1999
acquisitions through April 30, 1999 and the acquisition of Memogarde by
Britannia Data Management on January 1, 1998, our guarantor Subsidiaries would
have generated 92.7% of our

                                       33

consolidated revenues from continuing operations in the three month period ended
March 31, 1999 and held 90.3% of our consolidated assets as of March 31, 1999,
in each case without reduction for the 49.9% minority interest in Britannia Data
Management.

PRINCIPAL, MATURITY AND INTEREST

    The Notes are general unsecured obligations of the Company, are limited in
aggregate principal amount to $150.0 million and will mature on July 1, 2011.
Interest on the Notes will accrue at the rate of 8 1/4% per annum and will be
payable semi-annually in arrears on January 1 and July 1, commencing on July 1,
1999 to Holders of record on the immediately preceding December 15 and June 15.

    Interest on the new Notes will accrue from the most recent date on which
interest has been paid. Interest will be computed on the basis of a 360-day year
comprised of twelve 30-day months.

METHODS OF RECEIVING PAYMENTS ON THE NOTES

    The Notes are payable both as to principal and interest at the office or
agency of the Company maintained for such purpose within the City and State of
New York or, at the option of the Company, payment of interest may be made by
check mailed to the Holders of Notes at their addresses set forth in the
register of Holders of Notes. Until otherwise designated by the Company, the
Company's office or agency in New York is the office of the Trustee maintained
for such purpose. The old Notes were and the new Notes will be issued in
registered form, without coupons, and in denominations of $1,000 and integral
multiples thereof.

SUBSIDIARY GUARANTEES

    The Company's payment obligations under the Notes are jointly and severally
guaranteed pursuant to the Subsidiary Guarantees on an unsecured senior
subordinated basis by all of the Company's Restricted Subsidiaries other than
the Excluded Restricted Subsidiaries (as defined below). See "-- Certain
Covenants-- Additional Subsidiary Guarantees." Currently, Iron Mountain (Puerto
Rico) Inc. is the Company's only Excluded Restricted Subsidiary. Each Subsidiary
Guarantee is subordinated to the prior payment in full of all Senior Debt of
each such Guarantor, which on a pro forma basis, giving effect to our
acquisitions through April 30, 1999, Britannia Data Management's acquisition of
Memogarde, the issuance of the old Notes and our May 1999 equity offering, was
$6.2 million at March 31, 1999 for all Guarantors. Notwithstanding the
subordination provisions contained in the Indenture, the obligations of a
Guarantor under its Subsidiary Guarantee are unconditional. See "Risk Factors."

SUBORDINATION

    The payment of principal of, premium on, if any, and interest on the Notes
is subordinated in right of payment, as set forth in the Indenture, to the prior
payment in full in cash of all Obligations with respect to Senior Debt, whether
outstanding on the date of the Indenture or thereafter incurred.

    The holders of Senior Debt will be entitled to receive payment in full in
cash of all Obligations due in respect of such Senior Debt (including interest
after the commencement of any such proceeding at the rate specified in the
applicable Senior Debt, whether or not allowed as a claim in such proceeding)
before the Holders of Notes will be entitled to receive any payment or
distribution with respect to the Notes, and until all Obligations with respect
to Senior Debt are paid in full in cash, any payment or distribution to which
the Holders of Notes would be entitled shall be made to the holders of Senior
Debt, upon any payment or distribution to creditors of the Company or any
Guarantor:

        (1) in a liquidation or dissolution of the Company or such Guarantor, or

                                       34

        (2) in a bankruptcy, reorganization, insolvency, receivership or similar
    proceeding relating to the Company or any Guarantor or its property, or

        (3) in an assignment for the benefit of creditors, or

        (4) in any marshaling of the assets and liabilities of the Company or
    any Guarantor.

    Neither the Company nor any Guarantor may make any payment or distribution
upon or in respect of the Notes, including, without limitation, by way of
set-off or otherwise, or redeem (or make a deposit in redemption of), defease or
acquire any of the Notes for cash, properties or securities if:

        (1) a default in the payment of any Obligation in respect of any Senior
    Debt occurs and is continuing or

        (2) any other default (or any event that, after notice or passage of
    time would become a default) (a "Non-Monetary Default") occurs and is
    continuing with respect to Senior Debt and the Trustee receives a notice of
    such default (a "Payment Blockage Notice") from the holders (or the agent or
    representative of such holders) of any Designated Senior Debt.

    Payments on the Notes may and shall be resumed:

        (1) in the case of a payment default, on the date on which such default
    is cured or waived and

        (2) in the case of a Non-Monetary Default, on the earlier of the date on
    which such Non-Monetary Default is cured or waived or 179 days after the
    date on which the applicable Payment Blockage Notice is received, unless the
    maturity of any Senior Debt has been accelerated.

    Any number of Payment Blockage Notices may be given, provided, however,
that:

        (1) not more than one Payment Blockage Notice may be commenced during
    any period of 360 consecutive days and

        (2) any Non-Monetary Default that existed or was continuing on the date
    of delivery of any Payment Blockage Notice to the Trustee (to the extent the
    holder of Designated Senior Debt, or such trustee or agent, giving such
    Payment Blockage Notice had knowledge of the same) shall not be the basis
    for a subsequent Payment Blockage Notice, unless such default has been cured
    or waived for a period of not less than 90 consecutive days.

    The Indenture requires that the Company promptly notify holders of Senior
Debt if payment of the Notes is accelerated because of an Event of Default (as
described below).

    As a result of the subordination provisions described above, in the event of
a liquidation or insolvency, Holders of Notes may recover less ratably than
creditors of the Company who are holders of Senior Debt. After giving effect to
our 1999 acquisitions through April 30, 1999 and the acquisition of Memogarde by
Britannia Data Management, the use of the net proceeds of the offering of the
old Notes as described under "Use of Proceeds" and the use of the net proceeds
of the May 1999 equity offering as intended, the principal amount of Senior Debt
of the Company and the Restricted Subsidiaries outstanding at March 31, 1999 was
$6.2 million. The Indenture does not limit the amount of additional
Indebtedness, including Senior Debt, that the Company and its Subsidiaries can
incur if certain financial tests are met. See "--Certain Covenants--Incurrence
of Indebtedness and Issuance of Preferred Stock."

OPTIONAL REDEMPTION

    Prior to July 1, 2004, the Notes are subject to redemption at any time at
the option of the Company, in whole or in part, upon not less than 30 nor more
than 60 days' notice, at the Make-Whole Price, plus accrued and unpaid interest
and Liquidated Damages, if any, on the old Notes prior to the

                                       35

exchange offer, to but excluding the applicable redemption date. On and after
July 1, 2004, the Notes will be subject to redemption at any time at the option
of the Company, in whole or in part, upon not less than 30 nor more than 60
days' notice, at the redemption prices (expressed as percentages of principal
amount) set forth below, plus accrued and unpaid interest and Liquidated
Damages, if any, on the old Notes prior to the exchange offer, to but excluding
the applicable redemption date, if redeemed during the twelve-month period
beginning on July 1 of the years indicated below:



YEAR                                                                                PERCENTAGE
- ----------------------------------------------------------------------------------  -----------
                                                                                 
2004..............................................................................     104.125%
2005..............................................................................     102.750
2006..............................................................................     101.375
2007 and thereafter...............................................................     100.000%


    Notwithstanding the foregoing, at any time prior to July 1, 2002, the
Company may redeem up to 35% of the initial principal amount of the Notes
originally issued with the net proceeds of one or more Qualified Equity
Offerings at a redemption price equal to 108.25% of the principal amount of such
Notes, plus accrued and unpaid interest and Liquidated Damages, if any, on the
old Notes prior to the exchange offer, to but excluding the redemption date;
provided that at least 65% of the principal amount of Notes originally issued
remains outstanding immediately after the occurrence of any such redemption and
that such redemption occurs within 60 days following the closing of any such
Qualified Equity Offering.

MANDATORY REDEMPTION

    Except with respect to required repurchases upon the occurrence of a Change
of Control or in the event of certain Asset Sales, each as described below under
"--Repurchase at the Option of Holders," the Company is not required to make
sinking fund or redemption payments with respect to the Notes.

REPURCHASE AT THE OPTION OF HOLDERS

    CHANGE OF CONTROL

    Upon the occurrence of a Change of Control, each Holder of Notes will have
the right to require the Company to repurchase all or any part (equal to $1,000
or an integral multiple thereof) of such Holder's Notes pursuant to the offer
described below (the "Change of Control Offer") at an offer price in cash equal
to 101% of the aggregate principal amount thereof plus accrued and unpaid
interest and Liquidated Damages, if any, on the old Notes prior to the exchange
offer, to but excluding the date of repurchase (the "Change of Control
Payment").

    Within 30 calendar days following any Change of Control, the Company will
mail a notice to each Holder stating:

        (1) that the Change of Control Offer is being made pursuant to the
    covenant entitled "Change of Control" and that all Notes tendered will be
    accepted for payment,

        (2) the purchase price and the purchase date, which will be no earlier
    than 30 calendar days nor later than 60 calendar days from the date such
    notice is mailed (the "Change of Control Payment Date"),

        (3) that any Note not tendered will continue to accrue interest,

        (4) that, unless the Company defaults in the payment of the Change of
    Control Payment, all Notes accepted for payment pursuant to the Change of
    Control Offer will cease to accrue interest and Liquidated Damages, if any,
    on the old Notes prior to the exchange offer, on and after the Change of
    Control Payment Date,

                                       36

        (5) that Holders electing to have any Notes purchased pursuant to a
    Change of Control Offer will be required to surrender the Notes, with the
    form entitled "Option of Holder to Elect Purchase" on the reverse of the
    Notes completed, to the paying agent at the address specified in such notice
    prior to the close of business on the fifth Business Day preceding the
    Change of Control Payment Date,

        (6) that Holders will be entitled to withdraw their election if the
    paying agent receives, not later than the close of business on the second
    Business Day preceding the Change of Control Payment Date, a facsimile
    transmission or letter setting forth the name of the Holder, the principal
    amount of Notes delivered for purchase, and a statement that such Holder is
    withdrawing his election to have such Notes purchased, and

        (7) that Holders whose Notes are being purchased only in part will be
    issued new Notes equal in principal amount to the unpurchased portion of the
    Notes surrendered, which unpurchased portion must be equal to $1,000 in
    principal amount or an integral multiple thereof.

    The Company will comply with the requirements of Rule 14e-1 under the
Securities Exchange Act of 1934, as amended (the "Exchange Act") and any other
securities laws and regulations thereunder to the extent such laws and
regulations are applicable to the repurchase of the Notes in connection with a
Change of Control.

    On the Change of Control Payment Date, the Company will, to the extent
lawful:

        (1) accept for payment Notes or portions thereof tendered pursuant to
    the Change of Control Offer,

        (2) deposit with the paying agent an amount equal to the Change of
    Control Payment in respect of all Notes or portions thereof so tendered and

        (3) deliver or cause to be delivered to the Trustee the Notes so
    accepted together with an Officers' Certificate stating the Notes or
    portions thereof tendered to the Company.

    The paying agent will promptly mail to each Holder of Notes so accepted the
Change of Control Payment for such Notes, and the Trustee will promptly
authenticate and mail to each Holder a new Note equal in principal amount to any
unpurchased portion of the Notes surrendered, if any; provided that each such
new Note will be in a principal amount of $1,000 or an integral multiple
thereof.

    Except as described above with respect to a Change of Control, the Indenture
does not contain provisions that permit the Holders of the Notes to require that
the Company repurchase or redeem the Notes in the event of a takeover,
recapitalization or similar restructuring, nor does it contain any other "event
risk" protections for Holders of the Notes.

    Although the Change of Control provision may not be waived by the Company,
and may be waived by the Trustee only in accordance with the provisions of the
Indenture, there can be no assurance that any particular transaction (including
a highly leveraged transaction) cannot be structured or effected in a manner not
constituting a Change of Control.

    The Credit Agreement currently prohibits the Company from purchasing any
Notes prior to the expiration of the Credit Agreement and also provides that
certain change of control events with respect to the Company would constitute a
default thereunder. Any future credit agreements or other agreements relating to
Senior Debt to which the Company becomes a party may contain similar
restrictions and provisions. In the event a Change of Control occurs at a time
when the Company is prohibited from purchasing Notes, the Company could seek the
consent of its lenders to the purchase of Notes or could attempt to refinance
the borrowings that contain such prohibition. If the Company does not obtain
such a consent or repay such borrowings, the Company will remain prohibited from
purchasing Notes. In such case, the Company's failure to purchase tendered Notes
would constitute an

                                       37

Event of Default under the Indenture which would, in turn, constitute a default
under the Credit Agreement. In such circumstances, the subordination provisions
in the Indenture would likely restrict payments to the Holders of Notes.

ASSET SALES

    The Indenture provides that the Company will not, and will not permit any of
its Restricted Subsidiaries to:

        (1) sell, lease, convey or otherwise dispose of any assets (including by
    way of a Sale and Leaseback Transaction, but excluding a Qualifying Sale and
    Leaseback Transaction) other than sales of inventory in the ordinary course
    of business (provided that the sale, lease, conveyance or other disposition
    of all or substantially all of the assets of the Company will be governed by
    the provisions of the Indenture described above under the caption "Change of
    Control" and/or the provisions described below under the caption "Merger,
    Consolidation or Sale of Assets" and not by the provisions of this covenant)
    or

        (2) issue or sell Equity Interests of any of its Restricted Subsidiaries
    that, in the case of either clause (1) or (2) above, whether in a single
    transaction or a series of related transactions:
           (i) have a fair market value in excess of $2.0 million or
           (ii) result in Net Proceeds in excess of $2.0 million (each of the
       foregoing, an "Asset Sale"), unless (x) the Company (or the Restricted
       Subsidiary, as the case may be) receives consideration at the time of
       such Asset Sale at least equal to the fair market value (evidenced by an
       Officers' Certificate delivered to the Trustee, and for Asset Sales
       having a fair market value or resulting in net proceeds in excess of
       $10.0 million, evidenced by a resolution of the board of directors set
       forth in an Officers' Certificate delivered to the Trustee) of the assets
       sold or otherwise disposed of and (y) at least 75% of the consideration
       therefor received by the Company or such Restricted Subsidiary is in the
       form of cash or like-kind assets (in each case as determined in good
       faith by the Company, evidenced by a resolution of the board of directors
       and certified by an Officers' Certificate delivered to the Trustee),

provided, however, that the amount of

           (A) any liabilities (as shown on the Company's or such Restricted
       Subsidiary's most recent balance sheet or in the notes thereto) of the
       Company or such Restricted Subsidiary (other than liabilities that are by
       their terms subordinated to the Notes or any Subsidiary Guarantee) that
       are assumed by the transferee of any such assets and

           (B) any notes or other obligations received by the Company or such
       Restricted Subsidiary from such transferee that are immediately converted
       by the Company or such Restricted Subsidiary into cash (to the extent of
       the cash received) or Cash Equivalents,

shall be deemed to be cash for purposes of this provision; and provided,
further, that the 75% limitation referred to in the foregoing clause (ii)(y)
shall not apply to any Asset Sale in which the cash portion of the consideration
received therefrom is equal to or greater than what the after-tax proceeds would
have been had such Asset Sale complied with the aforementioned 75% limitation.

    A transfer of assets or issuance of Equity Interests by the Company to a
Wholly Owned Restricted Subsidiary or by a Wholly Owned Restricted Subsidiary to
the Company or to another Wholly Owned Restricted Subsidiary will not be deemed
to be an Asset Sale.

    Within 360 days of any Asset Sale, the Company may, at its option, apply an
amount equal to the Net Proceeds from such Asset Sale either:

                                       38

        (1) to permanently reduce Senior Debt or

        (2) to an investment in a Restricted Subsidiary or in another business
    or capital expenditure or other long-term/tangible assets, in each case, in
    the same line of business as the Company or any of its Restricted
    Subsidiaries was engaged in on the date of the Indenture or in businesses
    similar or reasonably related thereto.

    Pending the final application of any such Net Proceeds, the Company may
temporarily reduce Senior Bank Debt or otherwise invest such Net Proceeds in any
manner that is not prohibited by the Indenture. Any Net Proceeds from such Asset
Sale that are not applied or invested as provided in the first sentence of this
paragraph will be deemed to constitute "Excess Proceeds." When the aggregate
amount of Excess Proceeds exceeds $10.0 million, the Company shall make an offer
to all Holders of Notes and the holders of the 1997 Notes and any future
Indebtedness ranking PARI PASSU with the Notes, which Indebtedness contains
similar provisions requiring the Company to repurchase such Indebtedness (an
"Asset Sale Offer"), to purchase the maximum principal amount of Notes and such
other Indebtedness that may be purchased out of the Excess Proceeds, at an offer
price in cash in an amount equal to 100% of the principal amount thereof plus
accrued and unpaid interest, if any, to the date of purchase, in accordance with
the procedures set forth in the Indenture; provided, however, that prior to
making any such Asset Sale Offer, the Company may, to the extent required by the
1996 Indenture, use such Excess Proceeds to repurchase the 1996 Notes. To the
extent that the aggregate amount of Notes and other PARI PASSU Indebtedness
(including the 1997 Notes) tendered pursuant to an Asset Sale Offer is less than
the Excess Proceeds, the Company may use any remaining Excess Proceeds for
general corporate purposes. If the aggregate principal amount of Notes and such
other Indebtedness surrendered by Holders thereof exceeds the amount of Excess
Proceeds, the Trustee shall select the Notes and such other Indebtedness to be
purchased on a pro rata basis. Upon completion of such offer to purchase, the
amount of Excess Proceeds shall be reset at zero.

SELECTION AND NOTICE

    If less than all of the Notes are to be redeemed at any time, the Trustee
will select Notes for redemption as follows:

        (1) if the Notes are listed, in compliance with the requirements of the
    principal national securities exchange on which the Notes are listed, or

        (2) if the Notes are not so listed, on a pro rata basis, by lot or by
    such method as the Trustee shall deem fair and appropriate.

    No Notes of $1,000 or less shall be redeemed in part. Notices of redemption
shall be mailed by first class mail at least 30 but not more than 60 days before
the redemption date to each Holder of Notes to be redeemed at its registered
address.

    If any Note is to be redeemed in part only, the notice of redemption that
relates to such Note shall state the portion of the principal amount thereof to
be redeemed. A new Note in a principal amount equal to the unredeemed portion
thereof will be issued in the name of the Holder thereof upon cancellation of
the original Note. On and after the redemption date, interest and Liquidated
Damages, if any, will cease to accrue on Notes or portions thereof called for
redemption.

                                       39

CERTAIN COVENANTS

  RESTRICTED PAYMENTS

    The Indenture provides that the Company will not, and will not permit any of
its Restricted Subsidiaries to, directly or indirectly:

        (1) declare or pay any dividend or make any distribution on account of
    the Company's or any of its Restricted Subsidiaries' Equity Interests (other
    than dividends or distributions payable in Equity Interests (other than
    Disqualified Stock) of the Company or such Restricted Subsidiary or
    dividends or distributions payable to the Company or any Restricted
    Subsidiary),

        (2) purchase, redeem or otherwise acquire or retire for value any Equity
    Interests of the Company or any Restricted Subsidiary or other Affiliate of
    the Company (other than any such Equity Interests owned by the Company or
    any Restricted Subsidiary),

        (3) purchase, redeem or otherwise acquire or retire prior to scheduled
    maturity for value any Indebtedness that is subordinated in right of payment
    to the Notes or

        (4) make any Investment other than a Permitted Investment (all such
    payments and other actions set forth in clauses (1) through (4) above being
    collectively referred to as "Restricted Payments"),

    unless, at the time of such Restricted Payment:

           (i) no Default or Event of Default shall have occurred and be
       continuing or would occur as a consequence thereof, and

           (ii) the Company would, at the time of such Restricted Payment and
       after giving pro forma effect thereto, have been permitted to incur at
       least $1.00 of additional Indebtedness pursuant to the test set forth in
       the first paragraph of the covenant entitled "Incurrence of Indebtedness
       and Issuance of Preferred Stock" and

           (iii) such Restricted Payment, together with the aggregate of all
       other Restricted Payments made by the Company and its Restricted
       Subsidiaries after the date of the 1996 Indenture, is less than (x) the
       cumulative EBITDA of the Company, minus 1.75 times the cumulative
       Consolidated Interest Expense of the Company, in each case for the period
       (taken as one accounting period) from June 30, 1996 to the end of the
       Company's most recently ended fiscal quarter for which internal financial
       statements are available at the time of such Restricted Payment, plus (y)
       the aggregate net Equity Proceeds received by the Company from the
       issuance or sale since the date of the 1996 Indenture of Equity Interests
       of the Company or of debt securities of the Company that have been
       converted into such Equity Interests (other than Equity Interests or
       convertible debt securities sold to a Restricted Subsidiary of the
       Company and other than Disqualified Stock or debt securities that have
       been converted into Disqualified Stock), plus (z) $2.0 million.

    The foregoing provisions will not prohibit:

        (1) the payment of any dividend within 60 days after the date of
    declaration thereof, if at said date of declaration such payment would have
    complied with the provisions of the Indenture,

        (2) the redemption, repurchase, retirement or other acquisition or
    retirement for value of any Equity Interests of the Company in exchange for,
    or with the net cash proceeds of, the substantially concurrent sale (other
    than to a Restricted Subsidiary of the Company) of other Equity Interests of
    the Company (other than any Disqualified Stock),

        (3) the defeasance, redemption, repurchase, retirement or other
    acquisition or retirement for value of Indebtedness that is subordinated or
    PARI PASSU in right of payment to the Notes in

                                       40

    exchange for, or with the net cash proceeds of, a substantially concurrent
    issuance and sale (other than to a Restricted Subsidiary of the Company) of
    Equity Interests of the Company (other than Disqualified Stock),

        (4) the defeasance, redemption, repurchase, retirement or other
    acquisition or retirement for value of Indebtedness that is subordinated or
    PARI PASSU in right of payment to the Notes in exchange for, or with the net
    cash proceeds of, a substantially concurrent issue and sale (other than to
    the Company or any of its Restricted Subsidiaries) of Refinancing
    Indebtedness,

        (5) the repurchase of any Indebtedness subordinated or PARI PASSU in
    right of payment to the Notes at a purchase price not greater than 101% of
    the principal amount of such Indebtedness in the event of a Change of
    Control in accordance with provisions similar to the "Change of Control"
    covenant, provided that prior to or contemporaneously with such repurchase
    the Company has made the Change of Control Offer as provided in such
    covenant with respect to the Notes and has repurchased all Notes validly
    tendered for payment in connection with such Change of Control Offer, and

        (6) additional payments to current or former employees or directors of
    the Company for repurchases of stock, stock options or other equity
    interests, provided that the aggregate amount of all such payments under
    this clause (6) does not exceed $0.5 million in any year and $2.0 million in
    the aggregate.

    The Restricted Payments described in clauses (2), (3), (5) and (6) of the
immediately preceding paragraph will be Restricted Payments that will be
permitted to be taken in accordance with such paragraph but will reduce the
amount that would otherwise be available for Restricted Payments under clause
(iii) of the first paragraph of this section, and the Restricted Payments
described in clauses (1) and (4) of the immediately preceding paragraph will be
Restricted Payments that will be permitted to be taken in accordance with such
paragraph and will not reduce the amount that would otherwise be available for
Restricted Payments under clause (iii) of the first paragraph of this section.

    If an Investment results in the making of a Restricted Payment, the
aggregate amount of all Restricted Payments deemed to have been made as
calculated under the foregoing provision will be reduced by the amount of any
net reduction in such Investment (resulting from the payment of interest or
dividends, loan repayment, transfer of assets or otherwise) to the extent such
net reduction is not included in the Company's EBITDA; provided, however, that
the total amount by which the aggregate amount of all Restricted Payments may be
reduced may not exceed the lesser of (a) the cash proceeds received by the
Company and its Restricted Subsidiaries in connection with such net reduction
and (b) the initial amount of such Investment.

    If the aggregate amount of all Restricted Payments calculated under the
foregoing provision includes an Investment in an Unrestricted Subsidiary or
other Person that thereafter becomes a Restricted Subsidiary, such Investment
will no longer be counted as a Restricted Payment for purposes of calculating
the aggregate amount of Restricted Payments. For the purpose of making any
calculations under the Indenture:

        (1) an Investment will include the fair market value of the net assets
    of any Restricted Subsidiary at the time that such Restricted Subsidiary is
    designated an Unrestricted Subsidiary and will exclude the fair market value
    of the net assets of any Unrestricted Subsidiary that is designated as a
    Restricted Subsidiary,

        (2) any property transferred to or from an Unrestricted Subsidiary will
    be valued at fair market value at the time of such transfer, provided that,
    in each case, the fair market value of an asset or property is as determined
    by the board of directors in good faith, and

                                       41

        (3) subject to the foregoing, the amount of any Restricted Payment, if
    other than cash, will be determined by the board of directors, whose good
    faith determination will be conclusive.

    The board of directors may designate a Restricted Subsidiary to be an
Unrestricted Subsidiary in compliance with the covenant entitled "Unrestricted
Subsidiaries." Upon such designation, all outstanding Investments by the Company
and its Restricted Subsidiaries (except to the extent repaid in cash) in the
Subsidiary so designated will be deemed to be Restricted Payments made at the
time of such designation and will reduce the amount available for Restricted
Payments under the first paragraph of this covenant. Such designation will only
be permitted if such Restricted Payment would be permitted at such time and if
such Restricted Subsidiary otherwise meets the definition of an Unrestricted
Subsidiary.

  INCURRENCE OF INDEBTEDNESS AND ISSUANCE OF PREFERRED STOCK

    The Indenture provides that the Company will not, and will not permit any of
its Restricted Subsidiaries to, directly or indirectly, create, incur, issue,
assume, guaranty or otherwise become directly or indirectly liable with respect
to (collectively, "incur") any Indebtedness (including Acquired Debt) and that
the Company will not permit any of its Restricted Subsidiaries to issue any
shares of preferred stock; provided, however, that the Company may incur
Indebtedness and may permit a Restricted Subsidiary to incur Indebtedness if at
the time of such incurrence and after giving effect thereto the Leverage Ratio
would be less than 6.5 to 1.0.

    The foregoing limitations will not apply to:

        (1) the incurrence by the Company or any Restricted Subsidiary of Senior
    Bank Debt in an aggregate amount not to exceed $100.0 million at any one
    time outstanding,

        (2) the issuance by the Restricted Subsidiaries of Subsidiary
    Guarantees,

        (3) the incurrence by the Company and its Restricted Subsidiaries of the
    Existing Indebtedness,

        (4) the issuance by the Company of the Notes,

        (5) the incurrence by the Company and its Restricted Subsidiaries of
    Capital Lease Obligations and/or additional Indebtedness constituting
    purchase money obligations up to an aggregate of $5.0 million at any one
    time outstanding, provided that the Liens securing such Indebtedness
    constitute Permitted Liens,

        (6) the incurrence of Indebtedness between (i) the Company and its
    Restricted Subsidiaries and (ii) the Restricted Subsidiaries,

        (7) Hedging Obligations that are incurred for the purpose of fixing or
    hedging interest rate risk with respect to any floating rate Indebtedness
    that is permitted by the terms of the Indenture to be outstanding,

        (8) the incurrence by the Company and its Restricted Subsidiaries of
    Indebtedness arising out of letters of credit, performance bonds, surety
    bonds and bankers' acceptances incurred in the ordinary course of business
    up to an aggregate of $5.0 million at any one time outstanding,

        (9) the incurrence by the Company and its Restricted Subsidiaries of
    Indebtedness consisting of guarantees, indemnities or obligations in respect
    of purchase price adjustments in connection with the acquisition or
    disposition of assets, including, without limitation, shares of Capital
    Stock, and

        (10) the incurrence by the Company and its Restricted Subsidiaries of
    Refinancing Indebtedness issued in exchange for, or the proceeds of which
    are used to repay, redeem, defease,

                                       42

    extend, refinance, renew, replace or refund, Indebtedness referred to in
    clauses (2) through (5) above, and this clause (10).

    There are additional limitations on the ability of some Excluded Restricted
Subsidiaries to incur Indebtedness as provided in the covenant described under
the caption "Dividend and Other Payment Restrictions Affecting Restricted
Subsidiaries."

  LIENS

    The Indenture provides that neither the Company nor any of its Restricted
Subsidiaries may directly or indirectly create, incur, assume or suffer to exist
any Lien (other than a Permitted Lien) upon any property or assets now owned or
hereafter acquired, or any income, profits or proceeds therefrom, or assign or
otherwise convey any right to receive income therefrom, unless (a) in the case
of any Lien securing any Indebtedness that is subordinate to the Notes, the
Notes are secured by a Lien on such property, assets or proceeds that is senior
in priority to such Lien and (b) in the case of any other Lien, the Notes are
equally and ratably secured with the obligation or liability secured by such
Lien.

  DIVIDEND AND OTHER PAYMENT RESTRICTIONS AFFECTING RESTRICTED SUBSIDIARIES

    The Indenture provides that the Company will not, and will not permit any of
its Restricted Subsidiaries to, directly or indirectly, create or otherwise
cause or suffer to exist or become effective any encumbrance or restriction on
the ability of any Restricted Subsidiary to:

        (1) (i) pay dividends or make any other distributions to the Company or
    any of its Restricted Subsidiaries (A) on its Capital Stock or (B) with
    respect to any other interest or participation in, or measured by, its
    profits, or (ii) pay any Indebtedness owed to the Company or any of its
    Restricted Subsidiaries,

        (2) make loans or advances to the Company or any of its Restricted
    Subsidiaries or

        (3) transfer any of its properties or assets to the Company or any of
    its Restricted Subsidiaries.

    However, the preceding restrictions will not apply to encumbrances or
restrictions existing under or by reason of:

        (1) Existing Indebtedness,

        (2) the Credit Agreement as in effect as of the date of the Indenture,
    and any amendments, modifications, restatements, renewals, increases,
    supplements, refundings, replacements or refinancing thereof, provided that
    such amendments, modifications, restatements, renewals, increases,
    supplements, refundings, replacements or refinancings are no more
    restrictive in the aggregate with respect to such dividend and other payment
    restrictions than those contained in the Credit Agreement as in effect on
    the date of the Indenture,

        (3) the Indenture and the Notes,

        (4) applicable law,

        (5) any instrument governing Indebtedness or Capital Stock of a Person
    acquired by the Company or any of its Restricted Subsidiaries as in effect
    at the time of such acquisition (except to the extent such Indebtedness was
    incurred in connection with or in contemplation of such acquisition), which
    encumbrance or restriction is not applicable to any Person, or the
    properties or assets of any Person, other than the Person, or the property
    or assets of the Person, so acquired, provided that the EBITDA of such
    Person is not taken into account in determining whether such acquisition was
    permitted by the terms of the Indenture,

                                       43

        (6) customary non-assignment provisions in leases entered into in the
    ordinary course of business and consistent with past practices,

        (7) restrictions on the transfer of property subject to purchase money
    obligations or Capital Lease Obligations otherwise permitted by clause (5)
    of the covenant entitled "Incurrence of Indebtedness and Issuance of
    Preferred Stock,"

        (8) permitted Refinancing Indebtedness, provided that the restrictions
    contained in the agreements governing such Refinancing Indebtedness are no
    more restrictive in the aggregate than those contained in the agreements
    governing the Indebtedness being refinanced, or

        (9) any agreement or instrument governing Indebtedness of an Excluded
    Restricted Subsidiary provided that (i) at the time such agreement or
    instrument is entered into, such Excluded Restricted Subsidiary and its
    Restricted Subsidiaries have a Leverage Ratio of less than 6.5 to 1.0 and
    (ii) neither such Excluded Restricted Subsidiary nor any of its Restricted
    Subsidiaries shall, directly or indirectly, incur any Indebtedness
    (including Acquired Debt) unless at the time of such incurrence and after
    giving effect thereto, the Leverage Ratio for such Excluded Restricted
    Subsidiary and its Restricted Subsidiaries would be less than 6.5 to 1.0.
    For purposes of determining the Leverage Ratio under this clause (9) only,
    all references to the "Company" and its "Restricted Subsidiaries" or similar
    references in the definition of "Leverage Ratio" and other defined terms
    necessary to determine the Leverage Ratio shall be deemed to refer to such
    Excluded Restricted Subsidiary and its Restricted Subsidiaries,
    respectively.

  MERGER, CONSOLIDATION, OR SALE OF ASSETS

    The Indenture provides that the Company may not consolidate or merge with or
into (whether or not the Company is the surviving corporation), or sell, assign,
transfer, lease, convey or otherwise dispose of all or substantially all of its
properties or assets in one or more related transactions, to another Person
unless:

        (1) the Company is the surviving corporation or the Person formed by or
    surviving any such consolidation or merger (if other than the Company) or to
    which such sale, assignment, transfer, lease, conveyance or other
    disposition shall have been made is a corporation organized or existing
    under the laws of the United States, any state thereof or the District of
    Columbia,

        (2) the Person formed by or surviving any such consolidation or merger
    (if other than the Company) or the Person to which such sale, assignment,
    transfer, lease, conveyance or other disposition shall have been made
    assumes all the obligations of the Company under the Notes, the Indenture
    (pursuant to a supplemental indenture in a form reasonably satisfactory to
    the Trustee) and the Registration Rights Agreement,

        (3) immediately after such transaction no Default or Event of Default
    exists and

        (4) the Company or any Person formed by or surviving any such
    consolidation or merger, or to which such sale, assignment, transfer, lease,
    conveyance or other disposition shall have been made, will, at the time of
    such transaction and after giving pro forma effect thereto, be permitted to
    incur at least $1.00 of additional Indebtedness pursuant to the test set
    forth in the first paragraph of the covenant entitled "Incurrence of
    Indebtedness and Issuance of Preferred Stock."

  TRANSACTIONS WITH AFFILIATES

    The Indenture provides that the Company will not, and will not permit any of
its Restricted Subsidiaries to, sell, lease, transfer or otherwise dispose of
any of its properties or assets to, or purchase any property or assets from, or
enter into any contract, agreement, understanding, loan,

                                       44

advance or guarantee with, or for the benefit of, any Affiliate (each of the
foregoing, an "Affiliate Transaction"), unless:

        (a) such Affiliate Transaction is on terms that are no less favorable to
    the Company or the relevant Restricted Subsidiary than those that would have
    been obtained in a comparable transaction by the Company or such Restricted
    Subsidiary with a non-Affiliated Person and

        (b) the Company delivers to the Trustee:

           (i) with respect to any Affiliate Transaction involving aggregate
       payments in excess of $5.0 million, a resolution of the board of
       directors set forth in an Officers' Certificate certifying that such
       Affiliate Transaction complies with clause (a) above and such Affiliate
       Transaction is approved by a majority of the disinterested members of the
       board of directors and

           (ii) with respect to any Affiliate Transaction involving aggregate
       payments in excess of $10.0 million, an opinion as to the fairness to the
       Company or such Restricted Subsidiary from a financial point of view
       issued by an investment banking firm of national standing.

    The following items shall not be deemed Affiliate Transactions and
therefore, will not be subject to the provisions of the prior paragraph:

        (1) any employment agreement entered into by the Company or any of its
    Restricted Subsidiaries in the ordinary course of business and consistent
    with the past practice of the Company or such Restricted Subsidiary,

        (2) transactions between or among the Company and/or its Restricted
    Subsidiaries,

        (3) transactions permitted by the provisions of the Indenture described
    above under the covenant entitled "Restricted Payments" and

        (4) the grant of stock, stock options or other equity interests to
    employees and directors of the Company and any Restricted Subsidiary in
    accordance with duly adopted Company stock grant, stock option and similar
    plans.

    The provisions set forth in clause (b) above shall not apply to sales of
inventory by the Company or any Restricted Subsidiary to any Affiliate in the
ordinary course of business. The provisions of clause (b) (ii) above shall not
apply to loans or advances to the Company or any Restricted Subsidiary from, or
equity investments in the Company or any Restricted Subsidiary by, any Affiliate
to the extent permitted by the provisions of the Indenture described above under
the covenant entitled "Incurrence of Indebtedness and Issuance of Preferred
Stock."

  CERTAIN SENIOR SUBORDINATED DEBT

    The Indenture provides that the Company will not incur any Indebtedness that
is subordinated or junior in right of payment to any Senior Debt of the Company
and senior in any respect in right of payment to the Notes. The Company will not
permit any Restricted Subsidiary to incur any Indebtedness that is subordinated
or junior in right of payment to its Senior Debt and senior in any respect in
right of payment to its Subsidiary Guarantee.

  ADDITIONAL SUBSIDIARY GUARANTEES

    The Indenture provides that if any entity (other than an Excluded Restricted
Subsidiary) becomes a Restricted Subsidiary after the date of the Indenture,
then such Restricted Subsidiary shall execute a Subsidiary Guarantee and deliver
an opinion of counsel with respect thereto, in accordance with the terms of the
Indenture.

                                       45

    The Indenture provides that no Restricted Subsidiary (including any Excluded
Restricted Subsidiary) may consolidate with or merge with or into (whether or
not such Restricted Subsidiary is the surviving Person), another Person (other
than the Company) whether or not affiliated with such Restricted Subsidiary
unless:

        (1) subject to the provisions of the following paragraph, the Person
    formed by or surviving any such consolidation or merger (if other than such
    Restricted Subsidiary) assumes all the obligations of such Restricted
    Subsidiary under its Subsidiary Guaranty (except in the case of an Excluded
    Restricted Subsidiary) pursuant to a supplemental indenture in form and
    substance reasonably satisfactory to the Trustee,

        (2) immediately after giving effect to such transaction, no Default or
    Event of Default exists and

        (3) such Restricted Subsidiary, or any Person formed by or surviving any
    such consolidation or merger, would be permitted to incur, immediately after
    giving effect to such transaction, at least $1.00 of additional Indebtedness
    pursuant to the test set forth in the first paragraph of the covenant
    entitled "Incurrence of Indebtedness and Issuance of Preferred Stock."

    The Indenture provides that in the event of:

        (1) a sale or other disposition of all of the assets of any Restricted
    Subsidiary, by way of merger, consolidation or otherwise,

        (2) a sale or other disposition of all of the capital stock of any
    Restricted Subsidiary or

        (3) the designation of a Restricted Subsidiary as an Unrestricted
    Subsidiary in accordance with the terms of the covenant entitled
    "Unrestricted Subsidiaries,"

then such Subsidiary (in the event of a sale or other disposition, by way of
such a merger, consolidation or otherwise, of all of the capital stock of such
Restricted Subsidiary or in the event of the designation of such Restricted
Subsidiary as an Unrestricted Subsidiary) or the corporation acquiring the
property (in the event of a sale or other disposition of all of the assets of
such Restricted Subsidiary) will be released and relieved of any obligations
under its Subsidiary Guarantee, provided that the Net Proceeds of such sale or
other disposition are applied in accordance with the applicable provisions of
the Indenture. See "Repurchase at the Option of Holders--Asset Sales."

  UNRESTRICTED SUBSIDIARIES

    The board of directors may designate any Subsidiary (including any
Restricted Subsidiary or any newly acquired or newly formed Subsidiary) to be an
Unrestricted Subsidiary so long as:

        (1) neither the Company nor any Restricted Subsidiary is directly or
    indirectly liable for any Indebtedness of such Subsidiary,

        (2) no default with respect to any Indebtedness of such Subsidiary would
    permit (upon notice, lapse of time or otherwise) any holder of any other
    Indebtedness of the Company or any Restricted Subsidiary to declare a
    default on such other Indebtedness or cause the payment thereof to be
    accelerated or payable prior to its stated maturity,

        (3) any Investment in such Subsidiary deemed to be made as a result of
    designating such Subsidiary an Unrestricted Subsidiary will not violate the
    provisions of the covenant entitled "Restricted Payments,"

        (4) neither the Company nor any Restricted Subsidiary has a contract,
    agreement, arrangement, understanding or obligation of any kind, whether
    written or oral, with such Subsidiary other than (A) those that might be
    obtained at the time from Persons who are not

                                       46

    Affiliates of the Company or (B) administrative, tax sharing and other
    ordinary course contracts, agreements, arrangements and understandings or
    obligations entered into in the ordinary course of business, and

        (5) neither the Company nor any Restricted Subsidiary has any obligation
    to subscribe for additional shares of Capital Stock or other Equity
    Interests in such Subsidiary, or to maintain or preserve such Subsidiary's
    financial condition or to cause such Subsidiary to achieve certain levels of
    operating results other than as permitted under the covenant entitled
    "Restricted Payments."

    Notwithstanding the foregoing, the Company may not designate as an
Unrestricted Subsidiary any Subsidiary which, on the date of the Indenture, is a
Significant Subsidiary, and may not sell, transfer or otherwise dispose of any
properties or assets of any such Significant Subsidiary to an Unrestricted
Subsidiary, other than in the ordinary course of business, in each case, other
than Iron Mountain Global, Inc. and its Subsidiaries (including, without
limitation, Britannia Data Management Limited and its Subsidiaries).

    The board of directors may designate any Unrestricted Subsidiary as a
Restricted Subsidiary, provided that such designation will be deemed to be an
incurrence of Indebtedness by a Restricted Subsidiary of any outstanding
Indebtedness of such Unrestricted Subsidiary and such designation will only be
permitted if:

        (1) such Indebtedness is permitted under the "Incurrence of Indebtedness
    and Issuance of Preferred Stock" covenant and

        (2) no Default or Event of Default would occur as a result of such
    designation.

  LIMITATION ON SALE AND LEASEBACK TRANSACTIONS

    The Company will not, and will not permit any Restricted Subsidiary to,
enter into any Sale and Leaseback Transaction unless:

        (1) the consideration received in such Sale and Leaseback Transaction is
    at least equal to the fair market value of the property sold, as determined
    by a resolution of the board of directors of the Company and

        (2) the Company or such Restricted Subsidiary could incur the
    Attributable Indebtedness in respect of such Sale and Leaseback Transaction
    in compliance with the covenant entitled "Incurrence of Indebtedness and
    Issuance of Preferred Stock."

  REPORTS

    Whether or not required by the rules and regulations of the Commission, so
long as any Notes are outstanding, the Company will furnish to the Holders of
Notes:

        (1) all quarterly and annual financial information that would be
    required to be contained in a filing with the Commission on Forms 10-Q and
    10-K if the Company were required to file such Forms, including a
    "Management's Discussion and Analysis of Financial Condition and Results of
    Operations" and, with respect to the annual information only, a report
    thereon by the Company's certified independent accountants, and

        (2) all financial information that would be required to be included in a
    Form 8-K filed with the Commission if the Company were required to file such
    reports.

In addition, whether or not required by the rules and regulations of the
Commission, the Company will file a copy of all such information and reports
with the Commission for public availability (unless the Commission will not
accept such a filing) and make such information available to investors who
request it in writing.

                                       47

EVENTS OF DEFAULT AND REMEDIES

    The Indenture provides that each of the following will constitute an "Event
of Default":

        (1) default for 30 days in the payment when due of interest on the Notes
    or Liquidated Damages, if any, on the old Notes prior to the exchange offer
    (whether or not prohibited by the subordination provisions of the
    Indenture),

        (2) default in payment when due of the principal of or premium, if any,
    on the Notes (whether or not prohibited by the subordination provisions of
    the Indenture),

        (3) failure by the Company to comply with the provisions described under
    "Change of Control,"

        (4) failure by the Company or any Guarantor for 60 days after written
    notice from the Trustee or Holders of not less than 25% of the aggregate
    principal amount of the Notes outstanding to comply with any of its other
    agreements in the Indenture, Notes or the Subsidiary Guarantees,

        (5) default under any mortgage, indenture or instrument under which
    there may be issued or by which there may be secured or evidenced any
    Indebtedness for money borrowed by the Company or any of its Restricted
    Subsidiaries (or the payment of which is guaranteed by the Company or any of
    its Restricted Subsidiaries) whether such Indebtedness or guarantee exists
    on the date of the Indenture or is created thereafter, if:

           (i) such default results in the acceleration of such Indebtedness
       prior to its express maturity or shall constitute a default in the
       payment of such Indebtedness at final maturity of such Indebtedness and

           (ii) the principal amount of any such Indebtedness that has been
       accelerated or not paid at maturity, when added to the aggregate
       principal amount of all other such Indebtedness that has been accelerated
       or not paid at maturity, exceeds $10.0 million,

        (6) failure by the Company or any of its Restricted Subsidiaries to pay
    final judgments aggregating in excess of $10.0 million, which judgments
    remain unpaid, undischarged or unstayed for a period of 60 days,

        (7) certain events of bankruptcy or insolvency with respect to the
    Company or any of its Restricted Subsidiaries that are Significant
    Subsidiaries and

        (8) except as permitted by the Indenture or the Subsidiary Guarantees,
    any Subsidiary Guarantee issued by a Restricted Subsidiary shall be held in
    any judicial proceeding to be unenforceable or invalid or shall cease for
    any reason to be in full force and effect, or any Restricted Subsidiary or
    any Person acting on behalf of any Restricted Subsidiary shall deny or
    disaffirm in writing its obligations under its Subsidiary Guarantee.

    If any Event of Default occurs and is continuing, the Trustee or the Holders
of at least 25% in principal amount of the then outstanding Notes may declare
all the Notes to be due and payable immediately; provided, however, that if any
Obligation with respect to Senior Bank Debt is outstanding pursuant to the
Credit Agreement upon a declaration of acceleration of the Notes, the principal
of, premium on, if any, and interest on the Notes will not be payable until the
earlier of:

        (1) the day which is five business days after written notice of
    acceleration is received by the Company and the Credit Agent or

        (2) the date of acceleration of the Indebtedness under the Credit
    Agreement.

Notwithstanding the foregoing, in the case of an Event of Default arising from
certain events of bankruptcy or insolvency with respect to the Company or any
Restricted Subsidiary that is a Significant

                                       48

Subsidiary, the principal of, and premium on, if any, and any accrued and unpaid
interest on all outstanding Notes will become due and payable without further
action or notice.

    Holders of the Notes may not enforce the Indenture or the Notes except as
provided in the Indenture. In the event of a declaration of acceleration of the
Notes because an Event of Default has occurred and is continuing as a result of
the acceleration of any Indebtedness described in clause (5) of the preceding
paragraph, the declaration of acceleration of the Notes shall be automatically
annulled if the holders of any Indebtedness described in clause (5) have
rescinded the declaration of acceleration in respect of such Indebtedness within
30 days from the date of such declaration and if:

        (1) the annulment of the acceleration of the Notes would not conflict
    with any judgment or decree of a competent jurisdiction and

        (2) all existing Events of Default, except non-payment of principal or
    interest on the Notes that became due solely because of the acceleration of
    the Notes, have been cured or waived.

    In the case of any Event of Default occurring by reason of any willful
action (or inaction) taken (or not taken) by or on behalf of the Company with
the intention of avoiding payment of the Make Whole Price or premium, as
applicable, that the Company would have had to pay if the Company then had
elected to redeem the Notes pursuant to the optional redemption provisions of
the Indenture, the applicable Make Whole Price, or an equivalent premium, as the
case may be, shall become and be immediately due and payable to the extent
permitted by law upon the acceleration of the Notes.

    By notice to the Trustee, the Holders of a majority in aggregate principal
amount of the Notes then outstanding may, on behalf of the Holders of all of the
Notes, waive any existing Default or Event of Default and its consequences under
the Indenture except a continuing Default or Event of Default in the payment of
interest and Liquidated Damages, if any, on the old Notes or the principal of
the Notes. Subject to certain limitations, Holders of a majority in principal
amount of the then outstanding Notes may direct the Trustee in its exercise of
any trust or power. The Trustee may withhold from Holders of the Notes notice of
any continuing Default or Event of Default (except a Default or Event of Default
relating to the payment of principal or interest) if it determines that
withholding notice is in their interest.

    The Company is required to deliver to the Trustee annually a statement
regarding compliance with the Indenture, and the Company is required upon
becoming aware of any Default or Event of Default, to deliver to the Trustee a
statement specifying such Default or Event of Default.

NO PERSONAL LIABILITY OF DIRECTORS, OFFICERS, EMPLOYEES AND STOCKHOLDERS

    No director, officer, employee, incorporator or stockholder of the Company
or any Restricted Subsidiary, as such, shall have any liability for any
obligations of the Company or any Restricted Subsidiary under the Notes, the
Subsidiary Guarantees, the Indenture or the Registration Rights Agreement or for
any claim based on, in respect of, or by reason of, such obligations or their
creation. Each Holder of Notes by accepting a Note and the Subsidiary Guarantees
waives and releases all such liability. The waiver and release are part of the
consideration for issuance of the Notes and the Subsidiary Guarantees. Such
waiver may not be effective to waive liabilities under the federal securities
laws and it is the view of the Commission that such a waiver is against public
policy.

LEGAL DEFEASANCE AND COVENANT DEFEASANCE

    The Company may, at its option and at any time, elect to have all of its
obligations discharged with respect to the outstanding Notes ("Legal
Defeasance") except for:

        (1) the rights of Holders of outstanding Notes to receive payments in
    respect of the principal of, premium on, if any, and interest on such Notes
    when such payments are due,

                                       49

        (2) the Company's obligations with respect to issuing temporary Notes,
    registration of Notes, mutilated, destroyed, lost or stolen Notes and the
    maintenance of an office or agency for payment and money for security
    payments held in trust,

        (3) the rights, powers, trusts, duties and immunities of the Trustee,
    and the Company's obligations in connection therewith and

        (4) the Legal Defeasance provisions of the Indenture.

    In addition, the Company may, at its option and at any time, elect to have
its obligations with respect to certain covenants that are described in the
Indenture released ("Covenant Defeasance"), and thereafter any omission to
comply with such obligations shall not constitute a Default or Event of Default
with respect to the Notes. In the event Covenant Defeasance occurs, certain
events (not including non-payment, bankruptcy, receivership and insolvency
events) described under "Events of Default" will no longer constitute an Event
of Default with respect to the Notes.

    In order to exercise either Legal Defeasance or Covenant Defeasance:

        (1) the Company must irrevocably deposit with the Trustee, in trust, for
    the benefit of the Holders of the Notes, cash in Dollars, non-callable
    Government Securities, or a combination thereof, in such amounts as will be
    sufficient, in the opinion of a nationally recognized firm of independent
    public accountants, to pay the principal of, premium on, if any, and
    interest on the outstanding Notes on the stated maturity or on the
    applicable redemption date, as the case may be, of such principal or
    installment of principal of, premium on, if any, or interest on the
    outstanding Notes,

        (2) in the case of Legal Defeasance, the Company shall have delivered to
    the Trustee an opinion of counsel in the United States reasonably acceptable
    to the Trustee confirming that (i) the Company has received from, or there
    has been published by, the Internal Revenue Service a ruling or (ii) since
    the date of the Indenture, there has been a change in the applicable federal
    income tax law, in either case to the effect that, and based thereon such
    opinion of counsel shall confirm that, the Holders of the outstanding Notes
    will not recognize income, gain or loss for federal income tax purposes as a
    result of such Legal Defeasance and will be subject to federal income tax on
    the same amounts, in the same manner and at the same times as would have
    been the case if such Legal Defeasance had not occurred,

        (3) in the case of Covenant Defeasance, the Company shall have delivered
    to the Trustee an opinion of counsel in the United States reasonably
    acceptable to the Trustee confirming that the Holders of the outstanding
    Notes will not recognize income, gain or loss for federal income tax
    purposes as a result of such Covenant Defeasance and will be subject to
    federal income tax on the same amounts, in the same manner and at the same
    times as would have been the case if such Covenant Defeasance had not
    occurred,

        (4) no Default or Event of Default shall have occurred and be continuing
    on the date of such deposit or insofar as Events of Default from bankruptcy
    or insolvency events are concerned, at any time in the period ending on the
    91st day after the date of deposit,

        (5) such Legal Defeasance or Covenant Defeasance shall not result in a
    breach or violation of, or constitute a default under, any material
    agreement or instrument to which the Company or any of its Subsidiaries is a
    party or by which the Company or any of its Subsidiaries is bound,

        (6) the Company shall have delivered to the Trustee an opinion of
    counsel to the effect that after the 91st day following the deposit, the
    trust funds will not be subject to the effect of any applicable bankruptcy,
    insolvency, reorganization or similar laws affecting creditors' rights
    generally,

                                       50

        (7) the Company shall have delivered to the Trustee an Officers'
    Certificate stating that the deposit was not made by the Company with the
    intent of preferring the Holders of Notes over the other creditors of the
    Company with the intent of defeating, hindering, delaying or defrauding
    creditors of the Company or others and

        (8) the Company shall have delivered to the Trustee an Officers'
    Certificate and an opinion of counsel, each stating that all conditions
    precedent provided for relating to the Legal Defeasance or the Covenant
    Defeasance have been complied with.

TRANSFER AND EXCHANGE

    A Holder may transfer or exchange Notes in accordance with the Indenture.
The registrar and the Trustee may require a Holder, among other things, to
furnish appropriate endorsements and transfer documents and the Company may
require a Holder to pay any taxes and fees required by law or permitted by the
Indenture. The Company is not required to transfer or exchange any Note selected
for redemption. Also, the Company is not required to transfer or exchange any
Note for a period of 15 days before the mailing of a notice of redemption of
Notes to be redeemed.

    The registered Holder of a Note will be treated as the owner of it for all
purposes.

BOOK-ENTRY, DELIVERY AND FORM

    The old Notes, whether sold in the United States in reliance on Rule 144A or
in offshore transactions in reliance on Regulation S under the Securities Act,
are represented by a single, permanent Global Note (which has been subdivided)
in definitive, fully-registered form without interest coupons in minimum
denominations of $1,000 and integral multiples in excess thereof (the
"Restricted Global Note"). The Restricted Global Note was deposited with the
Trustee as custodian for DTC and registered in the name of a nominee of DTC for
credit to the respective accounts of the purchasers at DTC, Morgan Guaranty
Trust Company of New York, Brussels Office, as operators of Euroclear or Cedel
Bank.

    The Restricted Global Note, to the extent directed by the holders thereof in
their letters of transmittal, will be exchanged through book-entry electronic
transfer for a new Global Note in definitive fully-registered form without
interest coupons registered in the name of a nominee of DTC and held by the
Trustee as custodian. Except in the limited circumstances described below,
owners of beneficial interests in the Global Note will not be entitled to
receive physical delivery of Notes.

    Any old Notes that, subsequent to the completion of the offering of the old
Notes, were or, prior to the completion of the exchange offer, will be:

        (1) transferred to institutional "accredited investors" ("IAIs") (as
    defined in Rule 501(a)(1), (2), (3) or (7) of Regulation D under the
    Securities Act) who are not "qualified institutional buyers" ("QIBs") (as
    defined in Rule 144A),

        (2) issued in the limited circumstances described below or

        (3) issued as provided in the Indenture in reliance upon Rule 144 under
    the Securities Act,

have been or will be issued in definitive, fully registered form without
interest coupons in minimum denominations of $1,000 and integral multiples in
excess thereof (the "Definitive Notes").

    Upon the purchase of a Note, each IAI has been or will be required to
execute and deliver to the Company and the Trustee a letter containing certain
representations and agreements relating to the transfer of the Notes (the form
of which letter can be obtained from the Trustee) and an opinion of counsel, if
the Company or the Trustee so requests. If Definitive Notes initially issued to
an IAI are transferred to a QIB in reliance on Rule 144A or to non-U.S. persons
in compliance with Regulation S, such Definitive Notes will, unless the
Restricted Global Note has previously been exchanged in whole

                                       51

for Definitive Notes, be exchanged for an interest in the Restricted Global
Note. The Definitive Notes, to the extent directed by the holder thereof, will
be exchanged for new Notes in definitive fully registered form without interest
coupons.

    The Notes are not issuable in bearer form. The Global Note may be
transferred, in whole or in part, only to another nominee of DTC.

  THE GLOBAL NOTE

    Upon the issuance of the Global Note, DTC or its custodian will credit, on
its internal system, the respective principal amount of the individual
beneficial interests represented by the Global Note to the accounts of persons
who have accounts with DTC. Ownership of beneficial interests in the Global Note
will be limited to persons who have accounts with DTC ("participants") or
persons who hold interests through participants. Ownership of beneficial
interests in the Global Note will be shown on, and the transfer of that
ownership will be effected only through, records maintained by DTC or its
nominee (with respect to interests of participants) and the records of
participants (with respect to interests of persons other than participants).

    So long as DTC, or its nominee, is the registered owner or holder of the
Global Note, DTC or such nominee, as the case may be, will be considered the
sole owner or holder of the Notes represented by the Global Note for all
purposes under the Indenture and the Notes. Owners of beneficial interests in
the Global Note will not be considered to be the owners or holders of any Notes
under the Indenture. In addition, no beneficial owner of an interest in the
Global Note will be able to transfer that interest except in accordance with
DTC's applicable procedures (in addition to those under the Indenture referred
to herein and, if applicable, those of Euroclear and Cedel Bank).

    Investors may hold their interests in the Global Note directly through DTC
if they are participants in DTC, or indirectly through organizations which are
participants in DTC, including Cedel Bank and Euroclear. Cedel Bank and
Euroclear will hold interests in the Global Note on behalf of their participants
through their respective depositaries, which in turn will hold such interests in
the Global Note in customers' securities accounts in the depositaries' names on
the books of DTC. Citibank, New York will initially act as depositary for Cedel
Bank and The Chase Manhattan Bank, New York will initially act as depositary for
Euroclear.

    Payments of the principal, interest, premium and Liquidated Damages, if any,
for the old Notes, on the Global Note will be made to DTC or its nominee, as the
registered owner thereof. Neither the Company, the Trustee nor any Paying Agent
will have any responsibility or liability for any aspect of the records relating
to or payments made on account of beneficial ownership interests in the Global
Note or for maintaining, supervising or reviewing any records relating to such
beneficial ownership interests.

    The Company expects that DTC or its nominee, upon receipt of any payment of
principal, interest, premium or Liquidated Damages, if any, for the old Notes,
in respect of the Global Note, will immediately credit participants' accounts
with payments in amounts proportionate to their respective beneficial interests
in the principal amount of the Global Note as shown on the records of DTC or its
nominee. The Company also expects that payments by participants to owners of
beneficial interests in the Global Note held through such participants,
including Cedel Bank and Euroclear, will be governed by standing instructions
and customary practices and, in the case of Cedel Bank and Euroclear, in
accordance with the relevant system's rules and procedures. Such payments will
be the responsibility of such participants.

    Transfers between participants in DTC will be effected in the ordinary way
in accordance with DTC rules and will be settled in same-day funds. The laws of
some states require that certain persons take physical delivery of securities in
definitive form. Consequently, the ability to transfer beneficial interests in
Global Note to such persons may be limited. Because DTC can only act on behalf
of

                                       52

participants, who in turn act on behalf of indirect participants and certain
banks, the ability of a person having a beneficial interest in the Global Note
to pledge such interest to persons or entities that do not participate in the
DTC system, or otherwise take actions in respect of such interest, may be
affected by the lack of a physical certificate evidencing such interest.
Transfers between participants in Euroclear and Cedel Bank will be effected in
the ordinary way in accordance with their respective rules and operating
procedures.

    Cross-market transfers between DTC participants, on the one hand, and
directly or indirectly through Euroclear or Cedel Bank participants, on the
other, will be effected in DTC in accordance with DTC rules on behalf of
Euroclear or Cedel Bank, as the case may be, by its respective depositary;
however, such cross-market transactions will require delivery of instructions to
Euroclear or Cedel Bank, as the case may be, by the counterparty in such system
in accordance with its rules and procedures and within its established deadlines
(Brussels time). Euroclear or Cedel Bank, as the case may be, will, if the
transaction meets its settlement requirements, deliver instructions to its
respective depositary to take action to effect final settlement on its behalf by
delivering or receiving interests in the Global Note in DTC, and making or
receiving payment in accordance with normal procedures for same-day funds
settlement applicable to DTC. Cedel Bank participants and Euroclear participants
may not deliver instructions directly to the depositaries for Cedel Bank or
Euroclear.

    Because of time zone differences, the securities account of a Euroclear or
Cedel Bank participant purchasing an interest in the Global Note from a DTC
participant will be credited during the securities settlement processing day
(which must be a business day for Euroclear and Cedel Bank) immediately
following the DTC settlement date, and such credit will be reported to the
relevant Euroclear or Cedel Bank participant on such processing day. Cash
received in Euroclear or Cedel Bank as a result of sales of interests in the
Global Note by or through a Euroclear or Cedel Bank participant to a DTC
participant will be received with value on the DTC settlement date but will be
available in the relevant Euroclear or Cedel Bank cash accounts only as of the
business day following settlement in DTC.

    The Company expects that DTC will take any action permitted to be taken by a
holder of Notes, including the presentation of old Notes in exchange for new
Notes as described below, only at the direction of one or more participants to
whose account with DTC interests in the Restricted Global Note or the Global
Note, as the case may be, are credited and only in respect of such portion of
the aggregate principal amount of the Notes as to which such participant or
participants has or have given such direction. However, if an Event of Default
has occurred and is continuing or in the limited circumstances described below,
DTC will surrender the Global Note and certificated notes in definitive form
will be distributed to its participants. The giving of notices and other
communications by DTC to participants in DTC, by participants in DTC to persons
who hold accounts with them and by such persons to holders of beneficial
interests in the Global Note will be governed by arrangements between them,
subject to any statutory or regulatory requirements as may exist from time to
time.

    The Company understands that DTC is a limited-purpose trust company
organized under the New York Banking Law, a "banking organization" within the
meaning of the New York Banking Law, a member of the Federal Reserve System, a
"clearing corporation" within the meaning of the New York Uniform Commercial
Code, and a "clearing agency" registered pursuant to the provisions of Section
17A of the Exchange Act. DTC holds securities for its participants and
facilitates the clearance and settlement of securities transactions, such as
transfers and pledges, in deposited securities through electronic computerized
book-entry changes in participants' accounts, thereby eliminating the need for
physical movement of securities certificates. Participants include securities
brokers and dealers, banks, trust companies, clearing corporations, and certain
other organizations. DTC is owned by a number of its participants and by the New
York Stock Exchange, Inc., the American Stock Exchange, Inc., and the National
Association of Securities Dealers, Inc. Access to the DTC system is also
available to others such as securities brokers and dealers, banks, and trust
companies that clear through or maintain a

                                       53

custodial relationship with a participant, either directly or indirectly. The
rules applicable to DTC and its participants are on file with the Commission.

    Although DTC, Cedel Bank and Euroclear have agreed to the foregoing
procedures in order to facilitate transfers of interests in the Global Note
among participants of DTC, Cedel Bank and Euroclear, they are under no
obligation to perform or continue to perform such procedures, and such
procedures may be changed or discontinued at any time. Neither the Company nor
the Trustee will have any responsibility for the performance by DTC, Cedel Bank
or Euroclear or their respective participants or indirect participants of their
respective obligations under the rules and procedures governing their
operations.

    The Global Note is exchangeable for definitive Notes (i) if the Depositary
notifies the Company that it is unwilling or unable to continue as Depositary of
the Global Note and the Company thereupon fails to appoint a successor
Depositary, (ii) if the Company, at its option, notifies the Trustee in writing
that it elects to cause the issuance of the Notes in definitive registered form
or (iii) if there shall have occurred and be continuing an Event of Default or
any event which after notice or lapse of time or both would be an Event of
Default with respect to the Notes. Such definitive Notes shall be registered in
the names of the owners of the beneficial interests in the Global Note as
provided by the participants. Upon issuance of the Notes in definitive form, the
Trustee is required to register the Notes in the name of, and cause the Notes to
be delivered to, the person or persons (or the nominee thereof) identified as
the beneficial owners, as the Depositary shall direct.

  SETTLEMENT

    Payments in respect of the Notes represented by the Global Note, including
principal, interest and premium, and Liquidated Damages, if any, on the old
Notes prior to the exchange offer, will be made by wire transfer in immediately
available funds to the accounts specified by the registered owner of the Global
Note. With respect to any certificated Notes, the Company will make all payments
of principal, interest and premium, and Liquidated Damages, if any, on the old
Notes prior to the exchange offer, by wire transfer in immediately available
funds to the accounts specified by the Holders thereof or, if no such account is
specified, by mailing a check to such Holder's registered address. Secondary
trading in long-term notes of corporate issuers is generally settled in
clearing-house or next-day funds. In contrast, the beneficial interests in the
Global Note trade in DTC's Same-Day Funds Settlement System, in which secondary
market trading activity in those beneficial interests is required by DTC to
settle in immediately available funds. There is no assurance as to the effect,
if any, that settlement in immediately available funds would have on trading
activity in such beneficial interests.

AMENDMENT, SUPPLEMENT AND WAIVER

    Except as provided in the next two succeeding paragraphs, the Indenture or
the Notes may be amended or supplemented with the consent of the Holders of at
least a majority in principal amount of the Notes then outstanding (including
consents obtained in connection with a tender offer or exchange offer for
Notes), and any existing default or compliance with any provision of the
Indenture or the Notes may be waived with the consent of the Holders of a
majority in principal amount of the then outstanding Notes (including consents
obtained in connection with a tender offer or exchange offer for Notes).

    Without the consent of each Holder affected, an amendment or waiver may not
(with respect to any Notes held by a non-consenting Holder of Notes):

        (1) reduce the principal amount of Notes whose Holders must consent to
    an amendment, supplement or waiver,

        (2) reduce the principal of or change the fixed maturity of any Note or
    alter the provisions with respect to the redemption of the Notes in a manner
    adverse to the Holders of the Notes,

                                       54

        (3) reduce the rate of or change the time for payment of interest on any
    Note,

        (4) waive a Default or Event of Default in the payment of principal of
    or premium on, if any, or interest on the Notes (except a rescission of
    acceleration of the Notes by the Holders of at least a majority in aggregate
    principal amount of the then outstanding Notes and a waiver of the payment
    default that resulted from such acceleration),

        (5) make any Note payable in money other than that stated in the Notes,

        (6) make any change in the provisions of the Indenture relating to
    waivers of past Defaults or the rights of Holders of Notes to receive
    payments of principal of or premium on, if any, or interest on the Notes,

        (7) waive a redemption payment with respect to any Note (other than a
    payment required by one of the covenants described above under the caption
    "Repurchase at the Option of Holders"),

        (8) except pursuant to the Indenture, release any Restricted Subsidiary
    from its obligations under its Subsidiary Guarantee, or change any
    Subsidiary Guarantee in any manner that would materially adversely affect
    the Holders, or

        (9) make any change in the foregoing amendment and waiver provisions.

    Notwithstanding the foregoing, without the consent of any Holder of Notes,
the Company and the Trustee may amend or supplement the Indenture or the Notes
to cure any ambiguity, defect or inconsistency, to provide for uncertificated
Notes in addition to or in place of certificated Notes, to provide for the
assumption of the Company's obligations to Holders of the Notes in the case of a
merger or consolidation, to make any change that would provide any additional
rights or benefits to the Holders of the Notes or that does not adversely affect
the legal rights under the Indenture of any such Holder, or to comply with
requirements of the Commission in order to effect or maintain the qualification
of the Indenture under the Trust Indenture Act.

CONCERNING THE TRUSTEE

    The Indenture contains certain limitations on the rights of the Trustee,
should it become a creditor of the Company, to obtain payment of claims in
certain cases or to realize on certain property received in respect of any such
claim as security or otherwise. The Trustee will be permitted to engage in other
transactions. However, if it acquires any conflicting interest it must eliminate
such conflict within 90 days, resign or apply to the Commission for permission
to continue.

    The Holders of a majority in principal amount of the then outstanding Notes
will have the right to direct the time, method and place of conducting any
proceeding for exercising any remedy available to the Trustee, subject to
certain exceptions. The Indenture provides that in case an Event of Default
shall occur (which shall not be cured), the Trustee will be required, in the
exercise of its power, to use the degree of care of a prudent man in the conduct
of his own affairs. Subject to such provisions, the Trustee will be under no
obligation to exercise any of its rights or powers under the Indenture at the
request of any Holder of Notes, unless such Holder shall have offered to the
Trustee security and indemnity satisfactory to it against any loss, liability or
expense.

ADDITIONAL INFORMATION

    Anyone who receives this prospectus may obtain a copy of the Indenture
without charge by writing to Iron Mountain Incorporated, 745 Atlantic Avenue,
Boston, MA 02111, Attention: Executive Vice President/Chief Financial Officer.

                                       55

CERTAIN DEFINITIONS

    Set forth below are certain defined terms used in the Indenture. Reference
is made to the Indenture for a full disclosure of all such terms, as well as any
other capitalized terms used herein for which no definition is provided.

    "ACQUIRED DEBT" means, with respect to any specified Person:

        (1) Indebtedness of any other Person, existing at the time such other
    Person merged with or into or became a Subsidiary of such specified Person,
    including Indebtedness incurred in connection with, or in contemplation of,
    such other Person merging with or into or becoming a Subsidiary of such
    specified Person, and

        (2) Indebtedness encumbering any asset acquired by such specified
    Person.

    "ACQUISITION EBITDA" means, as of any date of determination, with respect to
an Acquisition EBITDA Entity, the sum of:

        (1) EBITDA of such Acquisition EBITDA Entity for its last fiscal quarter
    for which financial statements are available at such date of determination
    (adjusted to give pro forma effect to any acquisition or disposition of a
    business or Person by such Acquisition EDITDA Entity consummated during the
    period covered by, or after the date of, such quarterly financial
    statements), multiplied by four (or if such quarterly statements are not
    available, EBITDA for the most recent fiscal year for which financial
    statements are available), plus

        (2) projected quantifiable improvements in operating results (on an
    annualized basis) due to cost reductions calculated in good faith by the
    Company or one of its Restricted Subsidiaries, as certified by an Officers'
    Certificate filed with the Trustee, without giving effect to any operating
    losses of the acquired Person.

    "ACQUISITION EBITDA ENTITY" means, as of any date of determination, a
business or Person:

        (1) which has been acquired by the Company or one of its Restricted
    Subsidiaries and with respect to which financial results on a consolidated
    basis with the Company have not been made available for an entire fiscal
    quarter, or

        (2) which is to be acquired in whole or in part with Indebtedness, the
    incurrence of which will require the calculation on such date of the
    Acquisition EBITDA of such Acquisition EBITDA Entity for purposes of the
    covenant entitled "Incurrence of Indebtedness and Issuance of Preferred
    Stock."

    "ADJUSTED EBITDA" means, as of any date of determination and without
duplication, the sum of:

        (1) EBITDA of the Company and its Restricted Subsidiaries for the most
    recent fiscal quarter for which internal financial statements are available
    at such date of determination, multiplied by four, and

        (2) Acquisition EBITDA of each business or Person that is an Acquisition
    EBITDA Entity as of such date of determination, multiplied by a fraction,
    (i) the numerator of which is three minus the number of months (and/or any
    portion thereof) in such most recent fiscal quarter for which the financial
    results of such Acquisition EBITDA Entity are included in the EBITDA of the
    Company and its Restricted Subsidiaries under clause (1) above, and (ii) the
    denominator of which is three. The effects of unusual or non-recurring items
    in respect of the Company, a Restricted Subsidiary or an Acquisition EBITDA
    Entity occurring in any period shall be excluded in the calculation of
    Adjusted EBITDA.

    "AFFILIATE" of any specified Person means any other Person directly or
indirectly controlling or controlled by or under direct or indirect common
control with such specified Person. For purposes of

                                       56

this definition, "control" (including, with correlative meanings, the terms
"controlling," "controlled by" and "under common control with"), as used with
respect to any Person, shall mean the possession, directly or indirectly, of the
power to direct or cause the direction of the management or policies of such
Person, whether through the ownership of voting securities, by agreement or
otherwise; provided, however, that beneficial ownership of 10% or more of the
voting securities of a Person shall be deemed to be control.

    "ATTRIBUTABLE INDEBTEDNESS" in respect of a Sale and Leaseback Transaction
means, as of the time of determination, the greater of:

        (1) the fair market value of the property subject to such arrangement
    (as determined by the board of directors of the Company) and

        (2) the present value (discounted at the rate of interest implicit in
    such transaction) of the total obligations of the lessee for rental payments
    during the remaining terms of the lease included in such Sale and Leaseback
    Transaction (including any period for which such lease has been extended).

    "CAPITAL LEASE OBLIGATION" means, at the time any determination thereof is
to be made, the amount of the liability in respect of a capital lease that would
at such time be so required to be capitalized on the balance sheet in accordance
with GAAP.

    "CAPITAL STOCK" means any and all shares, interests, participations, rights
or other equivalents (however designated) of corporate stock, including, without
limitation, with respect to partnerships, partnership interests (whether general
or limited) and any other interest or participation that confers on a Person the
right to receive a share of the profits and losses of, or distributions of
assets of, such partnership.

    "CASH EQUIVALENTS" means:

        (1) securities with maturities of one year or less from the date of
    acquisition, issued, fully guaranteed or insured by the United States
    Government or any agency thereof,

        (2) certificates of deposit, time deposits, overnight bank deposits,
    bankers acceptances and repurchase agreements issued by a Qualified Issuer
    having maturities of 270 days or less from the date of acquisition,

        (3) commercial paper of an issuer rated at least A-2 by Standard &
    Poor's Rating Group, a division of McGraw Hill, Inc., or P-2 by Moody's
    Investors Service, or carrying an equivalent rating by a nationally
    recognized rating agency if both of the two named rating agencies cease
    publishing ratings of investments and having maturities of 270 days or less
    from the date of acquisition,

        (4) money market accounts or funds with or issued by Qualified Issuers
    and

        (5) Investments in money market funds substantially all of the assets of
    which are comprised of securities and other obligations of the types
    described in clauses (1) through (3) above.

    "CHANGE OF CONTROL" means the occurrence of any of the following events:

        (1) any "person" or "group" (as such terms are used in Sections 13(d)
    and 14(d) of the Exchange Act), other than the Principal Stockholders (or
    any of them), is or becomes the "beneficial owner" (as defined in Rules
    13d-3 and 13d-5 under the Exchange Act), directly or indirectly, of more
    than a majority of the voting power of all classes of Voting Stock of the
    Company,

        (2) the Company consolidates with, or merges with or into, another
    Person (as defined below) or conveys, transfers, leases or otherwise
    disposes of all or substantially all of its assets to any Person, or any
    Person consolidates with, or merges with or into, the Company, in any such
    event

                                       57

    pursuant to a transaction in which the outstanding Voting Stock of the
    Company is converted into or exchanged for cash, securities or other
    property, other than any such transaction where (i) the outstanding Voting
    Stock of the Company is not converted or exchanged at all (except to the
    extent necessary to reflect a change in the jurisdiction of incorporation)
    or is converted into or exchanged for (A) Voting Stock (other than
    Disqualified Stock) of the surviving or transferee Person or (B) cash,
    securities and other property (other than Capital Stock described in the
    foregoing clause (A)) of the surviving or transferee Person in an amount
    that could be paid as a Restricted Payment as described under the
    "Restricted Payments" covenant and (ii) immediately after such transaction,
    no "person" or "group" (as such terms are used in Sections 13(d) and 14(d)
    of the Exchange Act), other than the Principal Stockholders (or any of
    them), is the "beneficial owner" (as defined in Rules 13d-3 and 13d-5 under
    the Exchange Act), directly or indirectly, of more than a majority of the
    total outstanding Voting Stock of the surviving or transferee Person,

        (3) during any consecutive two-year period, individuals who at the
    beginning of such period constituted the board of directors (together with
    any new directors whose election to such board of directors, or whose
    nomination for election by the stockholders of the Company, was approved by
    a vote of 66 2/3% of the directors then still in office who were either
    directors at the beginning of such period or whose election or nomination
    for election was previously so approved) cease for any reason to constitute
    a majority of the board of directors then in office or

        (4) the Company is liquidated or dissolved or adopts a plan of
    liquidation or dissolution other than in a transaction which complies with
    the provisions described under "Consolidation, Merger and Sale of Assets."

    "CONSOLIDATED ADJUSTED NET INCOME" means, for any period, the net income (or
net loss) of the Company and its Restricted Subsidiaries for such period as
determined on a consolidated basis in accordance with GAAP, adjusted to the
extent included in calculating such net income or loss by excluding:

        (1) any net after-tax extraordinary gains or losses (less all fees and
    expenses relating thereto),

        (2) any net after-tax gains or losses (less all fees and expenses
    relating thereto) attributable to Asset Sales,

        (3) the portion of net income (or loss) of any Person (other than the
    Company or a Restricted Subsidiary), including Unrestricted Subsidiaries, in
    which the Company or any Restricted Subsidiary has an ownership interest,
    except to the extent of the amount of dividends or other distributions
    actually paid to the Company or any Restricted Subsidiary in cash dividends
    or distributions by such Person during such period, and

        (4) the net income (or loss) of any Person combined with the Company or
    any Restricted Subsidiary on a "pooling of interests" basis attributable to
    any period prior to the date of combination.

    "CONSOLIDATED INCOME TAX EXPENSE" means, for any period, the provision for
federal, state, local and foreign income taxes of the Company and its Restricted
Subsidiaries for such period as determined on a consolidated basis in accordance
with GAAP.

    "CONSOLIDATED INTEREST EXPENSE" means, for any period, without duplication,
the sum of:

        (1) the amount which, in conformity with GAAP, would be set forth
    opposite the caption "interest expense" (or any like caption) on a
    consolidated statement of operations of the Company and its Restricted
    Subsidiaries for such period, including, without limitation:

           (i) amortization of debt discount,

                                       58

           (ii) the net cost of interest rate contracts (including amortization
       of discounts),

           (iii) the interest portion of any deferred payment obligation,

           (iv) amortization of debt issuance costs and

           (v) the interest component of Capital Lease Obligations of the
       Company and its Restricted Subsidiaries, plus

        (2) all interest on any Indebtedness of any other Person guaranteed and
    paid by the Company or any of its Restricted Subsidiaries;

provided, however, that Consolidated Interest Expense will not include any gain
or loss from extinguishment of debt, including write-off of debt issuance costs.

    "CONSOLIDATED NON-CASH CHARGES" means, for any period, the aggregate
depreciation, amortization and other non-cash expenses of the Company and its
Restricted Subsidiaries (including without limitation any minority interest)
reducing Consolidated Adjusted Net Income for such period, determined on a
consolidated basis in accordance with GAAP (excluding any such non-cash charge
that requires an accrual of or reserve for cash charges for any future period).

    "CREDIT AGENT" means The Chase Manhattan Bank, in its capacity as
administrative agent for the lenders party to the Credit Agreement, or any
successor or successors party thereto.

    "CREDIT AGREEMENT" means that certain Second Amended and Restated Credit
Agreement, dated as of September 26, 1997, as amended, among the Company, the
lenders party thereto and the Credit Agent, as amended, restated, supplemented,
modified, renewed, refunded, increased, extended, replaced or refinanced from
time to time.

    "DEFAULT" means any event that is or with the passage of time or the giving
of notice or both would be an Event of Default.

    "DESIGNATED SENIOR DEBT" means:

        (1) Senior Bank Debt and

        (2) other Senior Debt the principal amount of which is $50.0 million or
    more at the date of designation by the Company in a written instrument
    delivered to the Trustee.

    Senior Debt designated as Designated Senior Debt pursuant to clause (2)
shall cease to be Designated Senior Debt at any time that the aggregate
principal amount thereof outstanding is $10.0 million or less.

    "DISQUALIFIED STOCK" means any Capital Stock which, by its terms (or by the
terms of any security into which it is convertible or for which it is
exchangeable), or upon the happening of any event, matures or is mandatorily
redeemable, for cash or other property (other than Capital Stock that is not
Disqualified Stock) pursuant to a sinking fund obligation or otherwise, or is
redeemable at the option of the Holder thereof, in whole or in part, in each
case on or prior to the stated maturity of the Notes.

    "DOLLARS" and "$" mean lawful money of the United States of America.

    "EBITDA" means for any period Consolidated Adjusted Net Income for such
period increased by:

        (1) Consolidated Interest Expense for such period, plus

        (2) Consolidated Income Tax Expense for such period, plus

        (3) Consolidated Non-Cash Charges for such period.

    "EQUITY INTERESTS" means Capital Stock and all warrants, options or other
rights to acquire Capital Stock (but excluding any debt security that is
convertible into, or exchangeable for, Capital Stock).

                                       59

    "EQUITY PROCEEDS" means:

        (1) with respect to Equity Interests (or debt securities converted into
    Equity Interests) issued or sold for cash Dollars, the aggregate amount of
    such cash Dollars and

        (2) with respect to Equity Interests (or debt securities converted into
    Equity Interests) issued or sold for any consideration other than cash
    Dollars, the aggregate Market Price thereof computed on the date of the
    issuance or sale thereof.

    "EXCLUDED RESTRICTED SUBSIDIARY" means any Restricted Subsidiary organized
under the laws of a jurisdiction other than the United States (as defined in
Regulation S under the Securities Act) and which has not delivered a Subsidiary
Guarantee.

    "EXISTING INDEBTEDNESS" means Indebtedness of the Company and its
Subsidiaries (other than under the Credit Agreement) in existence on the date of
the Indenture, until such amounts are repaid.

    "GOVERNMENT SECURITIES" means direct obligations of, or obligations
guaranteed by, the United States of America for the payment of which guarantee
or obligations the full faith and credit of the United States of America is
pledged.

    "GUARANTEE" means, as applied to any obligation:

        (1) a guarantee (other than by endorsement of negotiable instruments for
    collection in the ordinary course of business), direct or indirect, in any
    manner, of any part or all of such obligation and

        (2) an agreement, direct or indirect, contingent or otherwise, the
    practical effect of which is to assure in any way the payment or performance
    (or payment of damages in the event of non-performance) of all or any part
    of such obligation, including, without limiting the foregoing, the
    obligation to reimburse amounts drawn down under letters of credit securing
    such obligations.

    "HEDGING OBLIGATIONS" means, with respect to any Person, the obligations of
such Person under:

        (1) interest rate swap agreements, interest rate cap agreements and
    interest rate collar agreements and

        (2) other agreements or arrangements designed to protect such Person
    against fluctuations in interest rates.

    "INDEBTEDNESS" means (without duplication), with respect to any Person,
whether recourse is to all or a portion of the assets of such Person, and
whether or not contingent:

        (1) every obligation of such Person for money borrowed,

        (2) every obligation of such Person evidenced by bonds, debentures,
    notes or other similar instruments,

        (3) every reimbursement obligation of such Person with respect to
    letters of credit, bankers' acceptances or similar facilities issued for the
    account of such Person,

        (4) every obligation of such Person issued or assumed as the deferred
    purchase price of property or services,

        (5) every Capital Lease Obligation and every obligation of such Person
    in respect of Sale and Leaseback Transactions that would be required to be
    capitalized on the balance sheet in accordance with GAAP,

        (6) all Disqualified Stock of such Person valued at the greater of its
    voluntary or involuntary maximum fixed repurchase price, plus accrued and
    unpaid dividends (unless included in such maximum repurchase price),

                                       60

        (7) all obligations of such Person under or with respect to Hedging
    Obligations which would be required to be reflected on the balance sheet as
    a liability of such Person in accordance with GAAP and

        (8) every obligation of the type referred to in clauses (1) through (7)
    of another Person and dividends of another Person the payment of which, in
    either case, such Person has guaranteed.

    For purposes of this definition, the "maximum fixed repurchase price" of any
Disqualified Stock that does not have a fixed repurchase price will be
calculated in accordance with the terms of such Disqualified Stock as if such
Disqualified Stock were repurchased on any date on which Indebtedness is
required to be determined pursuant to the Indenture, and if such price is based
upon, or measured by, the fair market value of such Disqualified Stock, such
fair market value will be determined in good faith by the board of directors of
the issuer of such Disqualified Stock. Notwithstanding the foregoing, trade
accounts payable and accrued liabilities arising in the ordinary course of
business and any liability for federal, state or local taxes or other taxes owed
by such Person shall not be considered Indebtedness for purposes of this
definition. The amount outstanding at any time of any Indebtedness issued with
original issue discount is the aggregate principal amount at maturity of such
Indebtedness, less the remaining unamortized portion of the original issue
discount of such Indebtedness at such time, as determined in accordance with
GAAP.

    "INVESTMENTS" means, with respect to any Person, all investments by such
Person in other Persons (including Affiliates) in the forms of loans (including
Guarantees), advances or capital contributions (excluding commission, travel and
similar advances to officers and employees made in the ordinary course of
business), purchases or other acquisitions for consideration of Indebtedness,
Equity Interests or other securities and all other items that are or would be
classified as investments on a balance sheet prepared in accordance with GAAP.

    "LEVERAGE RATIO" means, at any date, the ratio of:

        (1) the aggregate principal amount of Indebtedness of the Company and
    its Restricted Subsidiaries outstanding as of the most recent available
    quarterly or annual balance sheet, to

        (2) Adjusted EBITDA, after giving pro forma effect, without duplication,
    to

           (i) the incurrence, repayment or retirement of any Indebtedness by
       the Company or its Restricted Subsidiaries since the last day of the most
       recent full fiscal quarter of the Company,

           (ii) if the Leverage Ratio is being determined in connection with the
       incurrence of Indebtedness by the Company or a Restricted Subsidiary,
       such Indebtedness and

           (iii) the Indebtedness to be incurred in connection with the
       acquisition of any Acquisition EBITDA Entity.

    "LIEN" means, with respect to any asset, any mortgage, lien, pledge, charge,
security interest or encumbrance of any kind in respect of such asset, whether
or not filed, recorded or otherwise perfected under applicable law (including
any conditional sale or other title retention agreement, any lease in the nature
thereof, any option or other agreement to sell or give a security interest in
and any filing of or agreement to give any financing statement under the Uniform
Commercial Code, or equivalent statutes, of any jurisdiction).

    "MAKE-WHOLE AMOUNT" means, with respect to any Note, an amount equal to the
excess, if any, of:

        (1) the present value of the remaining principal, premium and interest
    payments that would be payable with respect to such Note if such Note were
    redeemed on July 1, 2004, computed using a discount rate equal to the
    Treasury Rate plus 75 basis points, over

                                       61

        (2) the outstanding principal amount of such Note.

    "MAKE-WHOLE AVERAGE LIFE" means, with respect to any date of redemption of
Notes, the number of years (calculated to the nearest one-twelfth) from such
redemption date to July 1, 2004.

    "MAKE-WHOLE PRICE" means, with respect to any Note, the greater of:

        (1) the sum of the principal amount of and Make-Whole Amount with
    respect to such Note and

        (2) the redemption price of such Notes on July 1, 2004.

    "MARKET PRICE" means:

        (1) with respect to the calculation of Equity Proceeds from the issuance
    or sale of debt securities which have been converted into Equity Interests,
    the value received upon the original issuance or sale of such converted debt
    securities, as determined reasonably and in good faith by the board of
    directors, and

        (2) with respect to the calculation of Equity Proceeds from the issuance
    or sale of Equity Interests, the average of the daily closing prices for
    such Equity Interests for the 20 consecutive trading days preceding the date
    of such computation.

    The closing price for each day shall be:

        (1) if such Equity Interests are then listed or admitted to trading on
    the New York Stock Exchange, the closing price on the NYSE Consolidated Tape
    (or any successor consolidated tape reporting transactions on the New York
    Stock Exchange) or, if such composite tape shall not be in use or shall not
    report transactions in such Equity Interests, or if such Equity Interests
    shall be listed on a stock exchange other than the New York Stock Exchange
    (including for this purpose the Nasdaq National Market), the last reported
    sale price regular way for such day, or in case no such reported sale takes
    place on such day, the average of the closing bid and asked prices regular
    way for such day, in each case on the principal national securities exchange
    on which such Equity Interests are listed or admitted to trading (which
    shall be the national securities exchange on which the greatest number of
    such Equity Interests have been traded during such 20 consecutive trading
    days), or

        (2) if such Equity Interests are not listed or admitted to trading on
    any such exchange, the average of the closing bid and asked prices thereof
    in the over-the-counter market as reported by the National Association of
    Securities Dealers Automated Quotation System or any successor system, or if
    not included therein, the average of the closing bid and asked prices
    thereof furnished by two members of the National Association of Securities
    Dealers selected reasonably and in good faith by the board of directors for
    that purpose. In the absence of one or more such quotations, the Market
    Price for such Equity Interests shall be determined reasonably and in good
    faith by the board of directors.

    "NET PROCEEDS" means the aggregate cash proceeds received by the Company or
any of its Restricted Subsidiaries in respect of any Asset Sale, which amount is
equal to the excess, if any, of:

        (1) the cash received by the Company or such Restricted Subsidiary
    (including any cash payments received by way of deferred payment pursuant
    to, or monetization of, a note or installment receivable or otherwise, but
    only as and when received) in connection with such disposition, over

        (2) the sum of:

           (i) the amount of any Indebtedness which is secured by such asset and
       which is required to be repaid in connection with the disposition
       thereof, plus

                                       62

           (ii) the reasonable out-of-pocket expenses incurred by the Company or
       such Restricted Subsidiary, as the case may be, in connection with such
       disposition or in connection with the transfer of such amount from such
       Restricted Subsidiary to the Company, plus

           (iii) provisions for taxes, including income taxes, attributable to
       the disposition of such asset or attributable to required prepayments or
       repayments of Indebtedness with the proceeds thereof, plus

           (iv) if the Company does not first receive a transfer of such amount
       from the relevant Restricted Subsidiary with respect to the disposition
       of an asset by such Restricted Subsidiary and such Restricted Subsidiary
       intends to make such transfer as soon as practicable, the out-of-pocket
       expenses and taxes that the Company reasonably estimates will be incurred
       by the Company or such Restricted Subsidiary in connection with such
       transfer at the time such transfer is expected to be received by the
       Company (including, without limitation, withholding taxes on the
       remittance of such amount).

    "OBLIGATIONS" means any principal, interest (including post-petition
interest, whether or not allowed as a claim in any proceeding), penalties, fees,
costs, expenses, indemnifications, reimbursements, damages and other liabilities
payable under or in connection with any Indebtedness.

    "OFFICERS' CERTIFICATE" means a certificate signed, unless otherwise
specified, by any two of the Chairman of the Board, a Vice Chairman of the
Board, the President, the Chief Financial Officer, the Controller, or an
Executive Vice President of the Company, and delivered to the Trustee.

    "PERMITTED INVESTMENTS" means:

        (1) any Investments in the Company or in a Restricted Subsidiary (other
    than an Excluded Restricted Subsidiary) of the Company, including without
    limitation the Guarantee of Indebtedness permitted under the covenant
    entitled "Incurrence of Indebtedness and Issuance of Preferred Stock,"

        (2) any Investments in Cash Equivalents,

        (3) Investments by the Company or any Restricted Subsidiary of the
    Company in a Person, if as a result of such Investment:

           (i) such Person becomes a Restricted Subsidiary (other than an
       Excluded Restricted Subsidiary) of the Company or

           (ii) such Person is merged, consolidated or amalgamated with or into,
       or transfers or conveys substantially all of its assets to, or is
       liquidated into, the Company or a Restricted Subsidiary (other than an
       Excluded Restricted Subsidiary) of the Company,

        (4) Investments in assets (including accounts and notes receivable)
    owned or used in the ordinary course of business,

        (5) Investments for any purpose related to the Company's records
    management business (including, without limitation, the Company's
    outsourcing and staffing businesses) in an aggregate outstanding amount not
    to exceed $10.0 million and

        (6) Investments by the Company or a Restricted Subsidiary (other than an
    Excluded Restricted Subsidiary) in one or more Excluded Restricted
    Subsidiaries, the aggregate outstanding amount of which does not exceed 10%
    of the consolidated assets of the Company and its Restricted Subsidiaries.

    "PERMITTED LIENS" means:

        (1) Liens existing as of the date of issuance of the Notes,

                                       63

        (2) Liens on property or assets of the Company or any Restricted
    Subsidiary securing Senior Debt,

        (3) Liens on any property or assets of a Restricted Subsidiary granted
    in favor of the Company or any Wholly Owned Restricted Subsidiary,

        (4) Liens securing the Notes or the Guarantees,

        (5) any interest or title of a lessor under any Capital Lease Obligation
    or Sale and Leaseback Transaction so long as the Indebtedness, if any,
    secured by such Lien does not exceed the principal amount of Indebtedness
    permitted under the covenant entitled "Incurrence of Indebtedness and
    Issuance of Preferred Stock,"

        (6) Liens securing Acquired Debt created prior to (and not in connection
    with or in contemplation of) the incurrence of such Indebtedness by the
    Company or any Restricted Subsidiary; provided that such Lien does not
    extend to any property or assets of the Company or any Restricted Subsidiary
    other than the assets acquired in connection with the incurrence of such
    Acquired Debt,

        (7) Liens securing Hedging Obligations permitted to be incurred pursuant
    to clause (7) of the covenant entitled "Incurrence of Indebtedness and
    Issuance of Preferred Stock,"

        (8) Liens arising from purchase money mortgages and purchase money
    security interests, or in respect of the construction of property or assets,
    incurred in the ordinary course of the business of the Company or a
    Restricted Subsidiary; provided that (i) the related Indebtedness is not
    secured by any property or assets of the Company or any Restricted
    Subsidiary other than the property and assets so acquired or constructed and
    (ii) the Lien securing such Indebtedness is created within 60 days of such
    acquisition or construction,

        (9) statutory Liens or landlords' and carriers', warehousemen's,
    mechanics', suppliers', materialmen's, repairmen's or other like Liens
    arising in the ordinary course of business and with respect to amounts not
    yet delinquent or being contested in good faith by appropriate proceedings,
    if a reserve or other appropriate provision, if any, as shall be required in
    conformity with GAAP shall have been made therefor,

        (10) Liens for taxes, assessments, government charges or claims with
    respect to amounts not yet delinquent or that are being contested in good
    faith by appropriate proceedings diligently conducted, if a reserve or other
    appropriate provision, if any, as is required in conformity with GAAP has
    been made therefor,

        (11) Liens incurred or deposits made to secure the performance of
    tenders, bids, leases, statutory obligations, surety and appeal bonds,
    government contracts, performance bonds and other obligations of a like
    nature incurred in the ordinary course of business (other than contracts for
    the payment of money),

        (12) easements, rights-of-way, restrictions and other similar charges or
    encumbrances not interfering in any material respect with the business of
    the Company or any Restricted Subsidiary incurred in the ordinary course of
    business,

        (13) Liens arising by reason of any judgment, decree or order of any
    court so long as such Lien is adequately bonded and any appropriate legal
    proceedings that may have been duly initiated for the review of such
    judgment, decree or order shall not have been finally terminated or the
    period within which such proceedings may be initiated shall not have
    expired,

        (14) Liens arising under options or agreements to sell assets,

                                       64

        (15) other Liens securing obligations incurred in the ordinary course of
    business, which obligations do not exceed $10.0 million in the aggregate at
    any one time outstanding, and

        (16) any extension, renewal or replacement, in whole or in part, of any
    Lien described in the foregoing clauses (1) through (15); provided that any
    such extension, renewal or replacement shall not extend to any additional
    property or assets.

    "PERSON" means any individual, corporation, limited liability company,
partnership, joint venture, association, joint-stock company, trust,
unincorporated organization or government or any agency or political subdivision
thereof.

    "PRINCIPAL STOCKHOLDERS" means each of Vincent J. Ryan, Schooner Capital
LLC, C. Richard Reese, Kent P. Dauten, B. Thomas Golisano, Eugene B. Doggett and
their respective Affiliates.

    "QUALIFIED EQUITY OFFERING" means an offering of Capital Stock, other than
Disqualified Stock, of the Company for Dollars, whether registered or exempt
from registration under the Securities Act.

    "QUALIFIED ISSUER" means:

        (1) any lender party to the Credit Agreement or

        (2) any commercial bank:

           (i) which has capital and surplus in excess of $500,000,000 and

           (ii) the outstanding short-term debt securities of which are rated at
       least A-2 by Standard & Poor's Rating Group, a division of McGraw-Hill,
       Inc., or at least P-2 by Moody's Investors Service, or carry an
       equivalent rating by a nationally recognized rating agency if both of the
       two named rating agencies cease publishing ratings of investments.

    "QUALIFYING SALE AND LEASEBACK TRANSACTION" means any Sale and Leaseback
Transaction between the Company or any of its Restricted Subsidiaries and any
bank, insurance company or other lender or investor providing for the leasing to
the Company or such Restricted Subsidiary of any property (real or personal)
which has been or is to be sold or transferred by the Company or such Restricted
Subsidiary to such lender or investor or to any Person to whom funds have been
or are to be advanced by such lender or investor and where the property in
question has been constructed or acquired after the date of the Indenture.

    "REFINANCING INDEBTEDNESS" means new Indebtedness incurred or given in
exchange for, or the proceeds of which are used to repay, redeem, defease,
extend, refinance, renew, replace or refund other Indebtedness; provided,
however, that:

        (1) the principal amount of such new Indebtedness shall not exceed the
    principal amount of Indebtedness so repaid, redeemed, defeased, extended,
    refinanced, renewed, replaced or refunded (plus the amount of fees,
    premiums, consent fees, prepayment penalties and expenses incurred in
    connection therewith),

        (2) such Refinancing Indebtedness shall have a Weighted Average Life to
    Maturity equal to or greater than the Weighted Average Life to Maturity of
    the Indebtedness so repaid, redeemed, defeased, extended, refinanced,
    renewed, replaced or refunded or shall mature after the maturity date of the
    Notes,

        (3) to the extent such Refinancing Indebtedness refinances Indebtedness
    that has a final maturity date occurring after the initial scheduled
    maturity date of the Notes, such new Indebtedness shall have a final
    scheduled maturity not earlier than the final scheduled maturity of the
    Indebtedness so repaid, redeemed, defeased, extended, refinanced, renewed,
    replaced or refunded and shall not permit redemption at the option of the
    holder earlier than the earliest date

                                       65

    of redemption at the option of the holder of the Indebtedness so repaid,
    redeemed, defeased, extended, refinanced, renewed, replaced or refunded,

        (4) to the extent such Refinancing Indebtedness refinances Indebtedness
    subordinate to the Notes, such Refinancing Indebtedness shall be
    subordinated in right of payment to the Notes and to the extent such
    Refinancing Indebtedness refinances Notes or Indebtedness PARI PASSU with
    the Notes, such Refinancing Indebtedness shall be PARI PASSU with or
    subordinated in right of payment to the Notes, in each case on terms at
    least as favorable to the holders of Notes as those contained in the
    documentation governing the Indebtedness so repaid, redeemed, defeased,
    extended, refinanced, renewed, replaced or refunded, and

        (5) with respect to Refinancing Indebtedness incurred by a Restricted
    Subsidiary, such Refinancing Indebtedness shall rank no more senior, and
    shall be at least as subordinated, in right of payment to the Subsidiary
    Guarantee of such Restricted Subsidiary as the Indebtedness being extended,
    refinanced, renewed, replaced or refunded.

    "RESTRICTED SUBSIDIARY" means:

        (1) each direct or indirect Subsidiary of the Company, other than Iron
    Mountain Global, Inc. and its Subsidiaries (including Britannia Data
    Management Limited and its Subsidiaries), existing on the date of the
    Indenture and

        (2) any other direct or indirect Subsidiary of the Company formed,
    acquired or existing after the date of the Indenture (including any Excluded
    Restricted Subsidiaries), which, in the case of (1) or (2), is not
    designated by the board of directors as an "Unrestricted Subsidiary."

    "SALE AND LEASEBACK TRANSACTION" means any transaction or series of related
transactions pursuant to which a Person sells or transfers any property or asset
in connection with the leasing, or the resale against installment payments, of
such property or asset to the seller or transferor.

    "SENIOR BANK DEBT" means all Obligations outstanding under or in connection
with the Credit Agreement (including Guarantees of such Obligations by
Subsidiaries of the Company).

    "SENIOR DEBT" means:

        (1) the Senior Bank Debt and

        (2) any other Indebtedness permitted to be incurred by the Company or
    any Restricted Subsidiary, as the case may be, under the terms of the
    Indenture, unless the instrument under which such Indebtedness is incurred
    expressly provides that it is:

           (i) on a parity with or subordinated in right of payment to the Notes
       or

           (ii) subordinated to Senior Debt on terms substantially similar to
       those of the Notes.

    Notwithstanding anything to the contrary in the foregoing, Senior Debt shall
not include:

        (1) any liability for federal, state, local or other taxes owed or owing
    by the Company,

        (2) any Indebtedness of the Company to any of its Subsidiaries or other
    Affiliates,

        (3) any trade payables or

        (4) any Indebtedness that is incurred in violation of the Indenture,
    provided that such Indebtedness shall be deemed not to have been incurred in
    violation of the Indenture for purposes of this clause (4) if, in the case
    of any obligations under the Credit Agreement, the holders of such
    obligations or their agent or representative shall have received a
    representation from the Company to the effect that the incurrence of such
    Indebtedness does not violate the provisions of the Indenture.

                                       66

    "SIGNIFICANT SUBSIDIARY" means any Subsidiary that would be a "significant
subsidiary" as defined in Article 1, Rule 1-02 of Regulation S-X, promulgated
pursuant to the Act, as such Regulation is in effect on the date hereof.

    "SUBSIDIARY" means, with respect to any Person, any corporation, association
or other business entity of which more than 50% of the total voting power of
shares of Capital Stock entitled (without regard to the occurrence of any
contingency) to vote in the election of directors, managers or trustees thereof
is at the time owned or controlled, directly or indirectly, by such Person or
one or more of the other Subsidiaries of such Person or a combination thereof.

    "TREASURY RATE" means, at any time of computation, the yield to maturity at
such time (as compiled by and published in the most recent Federal Reserve
Statistical Release H.15(519), which has become publicly available at least two
business days prior to the date of the redemption notice or, if such Statistical
Release is no longer published, any publicly available source of similar market
data) of United States Treasury securities with a constant maturity most nearly
equal to the Make-Whole Average Life; provided, however, that if the Make-Whole
Average Life is not equal to the constant maturity of the United States Treasury
security for which a weekly average yield is given, the Treasury Rate shall be
obtained by linear interpolation (calculated to the nearest one-twelfth of a
year) from the weekly average yields of United States Treasury securities for
which such yields are given, except that if the Make-Whole Average Life is less
than one year, the weekly average yield on actually traded United States
Treasury securities adjusted to a constant maturity of one year shall be used.

    "UNRESTRICTED SUBSIDIARY" means:

        (1) any Subsidiary that is designated by the board of directors as an
    Unrestricted Subsidiary in accordance with the "Unrestricted Subsidiaries"
    covenant and

        (2) any Subsidiary of an Unrestricted Subsidiary.

    "VOTING STOCK" means any class or classes of Capital Stock pursuant to which
the holders thereof have the general voting power under ordinary circumstances
to elect at least a majority of the board of directors, managers or trustees of
any Person (irrespective of whether or not, at the time, stock of any other
class or classes has, or might have, voting power by reason of the happening of
any contingency).

    "WEIGHTED AVERAGE LIFE TO MATURITY" means, when applied to any Indebtedness
at any date, the number of years obtained by dividing:

        (1) the sum of the products obtained by multiplying (x) the amount of
    each then remaining installment, sinking fund, serial maturity or other
    required payment of principal, including payment at final maturity, in
    respect thereof, by (y) the number of years (calculated to the nearest one-
    twelfth) that will elapse between such date and the making of such payment,
    by

        (2) the then outstanding principal amount of such Indebtedness.

    "WHOLLY OWNED RESTRICTED SUBSIDIARY" means any Restricted Subsidiary of the
Company all of the outstanding Capital Stock or other ownership interests of
which (other than directors' qualifying shares) shall at the time be owned by
the Company or by one or more Wholly Owned Restricted Subsidiaries of the
Company.

                                       67

                   MATERIAL FEDERAL INCOME TAX CONSIDERATIONS

    The following summary of federal income tax considerations is based upon the
Internal Revenue Code of 1986, as amended, Treasury regulations and rulings and
decisions now in effect, all of which are subject to change or possible
differing interpretations. No ruling has been sought from the Internal Revenue
Service with respect to any matter described in this summary, and we cannot
provide any assurance that the IRS or a court will agree with the statements
made in this summary. The summary applies to you only if you hold the Notes as a
capital asset, which generally is an asset held for investment rather than as
inventory or as property used in a trade or business. The summary also does not
discuss the particular tax consequences that might be relevant to you if you are
subject to special rules under the federal income tax law, for example if you
are:

    - a bank, life insurance company, regulated investment company or other
      financial institution,

    - a broker or dealer in securities or foreign currency,

    - a person that has a functional currency other than the U.S. dollar,

    - a person who acquires our Notes in connection with his employment or other
      performance of services,

    - a person subject to alternative minimum tax,

    - a person who owns our Notes as part of a straddle, hedging transaction,
      conversion transaction or constructive sale transaction,

    - a tax-exempt entity or

    - an expatriate.

    In addition, the following summary does not address all possible tax
considerations, and in particular does not discuss any state, local or foreign
tax considerations. For all these reasons, we urge you to consult with your tax
advisor about the federal income tax and other tax consequences of your
acquisition, ownership and disposition of our Notes.

    For purposes of this summary, you are a "U.S. holder" if you are a
beneficial owner of our Notes and for federal income tax purposes are:

    - a citizen or resident of the United States, including an alien individual
      who is a lawful permanent resident of the United States or meets the
      substantial presence residency test under the federal income tax laws,

    - a corporation, partnership or other entity treated as a corporation or
      partnership for federal income tax purposes, that is created or organized
      in or under the laws of the United States, any state thereof or the
      District of Columbia, unless otherwise provided by Treasury regulations,

    - an estate the income of which is subject to federal income taxation
      regardless of its source or

    - a trust if a court within the United States is able to exercise primary
      supervision over the administration of the trust and one or more United
      States persons have the authority to control all substantial decisions of
      the trust, or electing trusts in existence on August 20, 1996 to the
      extent provided in Treasury regulations,

and if your status as a U.S. holder is not overridden pursuant to the provisions
of an applicable tax treaty. Conversely, you are a "non-U.S. holder" if you are
a beneficial owner of our Notes and are not a U.S. holder.

                                       68

EXCHANGE OFFER

    An exchange of the old Notes for the registered new Notes will be regarded
for federal income tax purposes as a nontaxable continuation of the old Notes,
and a holder will have the same adjusted basis and holding period in the new
Notes immediately after the exchange as it had in the old Notes immediately
before the exchange. Each Note will be treated as indebtedness issued by Iron
Mountain.

U.S. HOLDERS

    If you are a U.S. holder:

    PAYMENTS OF INTEREST.  You must generally include interest on a Note in your
gross income as ordinary interest income:

    - when you receive it, if you use the cash method of accounting for federal
      income tax purposes, or

    - when it accrues, if you use the accrual method of accounting for federal
      income tax purposes.

    Purchase price for a Note that is allocable to prior accrued interest may be
treated as offsetting a portion of the interest income from the next scheduled
interest payment on the Note.

    MARKET DISCOUNT.  If after its original issuance as an old Note you purchase
a Note for an amount less than its principal amount, you will be treated as
having purchased the Note at a "market discount" unless the amount of this
market discount is less than the DE MINIMIS amount specified under the Internal
Revenue Code. Under the market discount rules, you will be required to treat any
gain on the sale, exchange, redemption, retirement, or other taxable disposition
of a Note, or any appreciation in a Note in the case of a nontaxable disposition
such as a gift, as ordinary income to the extent of the market discount which
has not previously been included in your income and which is treated as having
accrued on the Note at the time of the disposition. In addition, you may be
required to defer, until the maturity of the Note or earlier taxable
disposition, the deduction of all or a portion of the interest expense on any
indebtedness incurred or continued to purchase or carry the Note. Any market
discount will be considered to accrue ratably during the period from the date of
your acquisition to the maturity date of the Note, unless you elect to accrue
the market discount on a constant yield method. In addition, you may elect to
include market discount in income currently as it accrues, on either a ratable
or constant yield method, in which case the rule described above regarding
deferral of interest deductions will not apply. This election to include market
discount in income currently, once made, applies to all market discount
obligations acquired on or after the first taxable year to which the election
applies and may not be revoked without the consent of the IRS. You should
consult with your tax advisor regarding these elections.

    AMORTIZABLE BOND PREMIUM.  If you purchase a Note for an amount greater than
its principal amount, you will be treated as having purchased the Note with
"bond premium." You generally may elect to amortize this bond premium over the
remaining term of the Note on a constant yield method, and the amount amortized
in any year will be treated as a reduction of your interest income from the Note
for that year. If you do not make such an election, your bond premium on a Note
will decrease the gain or increase the loss that you otherwise recognize on a
dispositon of that Note. Any election to amortize bond premium applies to all
debt obligations, other than debt obligations the interest on which is
excludable from gross income, that you hold at the beginning of the first
taxable year to which the election applies and that you thereafter acquire. You
may not revoke an election to amortize bond premium without the consent of the
IRS. You should consult with your tax advisor regarding this election.

    DISPOSITION OF A NOTE.  Upon the sale, exchange, redemption, retirement or
other disposition of a Note, you generally will recognize taxable gain or loss
in an amount equal to the difference, if any,

                                       69

between (1) the amount you receive in cash or in property, valued at its fair
market value, upon this sale, exchange, redemption, retirement or other
disposition, other than amounts representing accrued and unpaid interest which
will be taxable as interest income, and (2) your adjusted tax basis in the Note.
Your adjusted tax basis in the Note will, in general, equal your acquisition
cost for the Note, as increased by any market discount you have included into
income in respect of the Note, and as decreased by any amortized bond premium on
the Note. Except with respect to accrued market discount, your gain or loss will
be capital gain or loss, and will be long-term capital gain or loss if you have
held the Note for more than one year at the time of disposition. For
noncorporate U.S. holders, preferential rates of tax may apply to long-term
capital gains.

NON-U.S. HOLDERS

    If you are a non-U.S. holder:

    GENERALLY.  You will not be subject to federal income taxes on payments of
principal, premium, if any, or interest on a Note, or upon the sale, exchange,
redemption, retirement or other disposition of a Note, if:

    - you do not own directly or indirectly 10% or more of the total voting
      power of all classes of our voting stock,

    - your income and gain in respect of the Note is not effectively connected
      with the conduct of a United States trade or business,

    - you are not a controlled foreign corporation that is related to or under
      common control with us,

    - we or the applicable paying agent (the "Withholding Agent") have received
      from you a properly executed, applicable IRS Form W-8 or substantially
      similar form in the year in which a payment of interest, principal or
      premium occurs, or in a preceding calendar year to the extent provided for
      in the instructions to the applicable IRS Form W-8, and

    - in the case of gain upon the sale, exchange, redemption, retirement or
      other disposition of a Note recognized by an individual non-U.S. holder,
      you were present in the United States for less than 183 days during the
      taxable year in which the gain was recognized.

    The IRS Form W-8 or substantially similar form must be signed by you under
penalties of perjury certifying that you are a non-U.S. holder and providing
your name and address, and you must inform the Withholding Agent of any change
in the information on the statement within 30 days of the change. If you hold a
Note through a securities clearing organization or other qualified financial
institution, the organization or institution may provide a signed statement to
the Withholding Agent. However, in that case, the signed statement must
generally be accompanied by a copy of the executed IRS Form W-8 or substantially
similar form that you provided to the organization or institution.

    Except in the case of income or gain in respect of a Note that is
effectively connected with the conduct of a United States trade or business,
discussed below, interest received or gain recognized by you which does not
qualify for exemption from taxation will be subject to federal income tax and
withholding at a rate of 30% unless reduced or eliminated by an applicable tax
treaty. You must generally use IRS Form 1001 to claim tax treaty benefits.

    EFFECTIVELY CONNECTED INCOME AND GAIN.  If you are a non-U.S. holder whose
income and gain in respect of a Note is effectively connected with the conduct
of a United States trade or business, you will be subject to regular federal
income tax on this income and gain in generally the same manner as U.S. holders,
and general federal income tax return filing requirements will apply. In
addition, if you are a corporation, you may be subject to a branch profits tax
equal to 30% of your effectively connected adjusted earnings and profits for the
taxable year, unless you qualify for a lower rate under an applicable tax
treaty. To obtain an exemption from withholding on interest on the Notes, you
must

                                       70

generally supply to the Withholding Agent an IRS Form 4224 for 1999 and 2000,
and under new Treasury regulations discussed below, an applicable IRS Form W-8,
or substantially similar form, for subsequent calendar years.

    NEW TREASURY REGULATIONS.  New Treasury regulations alter the withholding
rules on interest paid to you, effective generally for payments after December
31, 2000 and subject to complex transition rules. For example, documentation and
procedures satisfying the new Treasury regulations are deemed in some instances
to satisfy current law requirements, and in these instances you or the
Withholding Agent may wish to satisfy the requirements of the new Treasury
regulations rather than the requirements of the Treasury regulations soon to
expire. The new Treasury regulations are complex, and you must therefore consult
with your tax advisor to determine how the new Treasury regulations affect your
particular circumstances.

    The new Treasury regulations replace old IRS Forms W-8, 1001 and 4224 with a
new series of IRS Forms W-8, which you will generally have to properly execute
earlier than you would have otherwise had to for purposes of providing
replacements for the old IRS forms. For example, you must properly execute the
appropriate new version of IRS Form W-8, or substantially similar form, no later
than December 31, 2000 if you remain a non-U.S. holder of a Note on that date.
Under the new Treasury regulations, it may also be possible for you to receive
payments on the Notes through a qualified intermediary that complies with
requisite procedures and provides applicable certification of your non-U.S.
holder status on your behalf. The new Treasury regulations also clarify
Withholding Agents' reliance standards on executed IRS Forms W-8 or
substantially similar forms.

    If you are a non-U.S. holder claiming benefits under an income tax treaty,
you should be aware that you may be required to obtain a taxpayer identification
number and to certify your eligibility under the applicable treaty's limitations
on benefits article in order to comply with the new Treasury regulations'
certification requirements. The new Treasury regulations also provide special
rules to determine whether, for purposes of determining the applicability of a
tax treaty, interest paid to a non-U.S. holder that is an entity should be
treated as paid to the entity or to those holding the ownership interests in
that entity, and whether the entity or the holders in the entity are entitled to
benefits under the tax treaty.

INFORMATION REPORTING AND BACKUP WITHHOLDING

    Information reporting and backup withholding may apply to interest and other
payments to you under the circumstances discussed below. Amounts withheld under
backup withholding are generally not an additional tax and may be refunded or
credited against your federal income tax liability, provided that you furnish
the required information to the IRS.

    IF YOU ARE A U.S. HOLDER.  You may be subject to backup withholding at a 31%
rate when you receive interest payments on a Note or proceeds upon the sale,
exchange, redemption, retirement or other disposition of a Note. In general, you
can avoid this backup withholding by properly executing under penalties of
perjury an IRS Form W-9 or substantially similar form that provides:

    - your correct taxpayer identification number and

    - you are exempt from backup withholding because (a) you are a corporation
      or come within another enumerated exempt category, (b) you have not been
      notified by the IRS that you are subject to backup withholding or (c) you
      have been notified by the IRS that you are no longer subject to backup
      withholding.

    If you do not provide your correct taxpayer identification number on the IRS
Form W-9 or substantially similar form, you may be subject to penalties imposed
by the IRS.

                                       71

    Unless you have established on a properly executed IRS Form W-9 or
substantially similar form that you are a corporation or come within another
enumerated exempt category, interest and other payments on the Notes paid to you
during the calendar year, and the amount of tax withheld, if any, will be
reported to you and to the IRS.

    IF YOU ARE A NON-U.S. HOLDER.  The amount of interest paid to you on a Note
during each calendar year, and the amount of tax withheld, if any, will
generally be reported to you and to the IRS. This information reporting
requirement applies regardless of whether you were subject to withholding or
whether withholding was reduced or eliminated by an applicable tax treaty. Also,
interest paid to you on a Note may be subject to backup withholding at a 31%
rate, unless you properly certify your non-U.S. holder status on an IRS Form W-8
or substantially similar form in the manner described above, under "Non-U.S.
Holders." Similarly, information reporting and 31% backup withholding will not
apply to proceeds you receive upon the sale, exchange, redemption, retirement or
other disposition of a Note, if you properly certify that you are a non-U.S.
holder on an IRS Form W-8 or substantially similar form. Even without having
executed an IRS Form W-8 or substantially similar form, however, in some cases
information reporting and 31% backup withholding will not apply to proceeds you
receive upon the sale, exchange, redemption, retirement or other disposition of
a Note, if you receive those proceeds through a broker's foreign office.

    If you are a non-U.S. holder whose income and gain on a Note is effectively
connected to the conduct of a United States trade or business, a slightly
different rule may apply to proceeds you receive upon the sale, exchange,
redemption, retirement or other disposition of a Note. Until you comply with the
new Treasury regulations discussed above under "Non-U.S. Holders," information
reporting and 31% backup withholding may apply to you in the same manner as a
U.S. holder, and thus you may have to execute an IRS Form W-9 or substantially
similar form to prevent the backup withholding.

                                       72

                              PLAN OF DISTRIBUTION

    Each broker-dealer that receives new Notes for its own account pursuant to
the exchange offer must acknowledge that it will deliver a prospectus in
connection with any resale of such new Notes. This prospectus, as it may be
amended or supplemented from time to time, may be used by a broker-dealer in
connection with resales of new Notes received in exchange for old Notes where
such old Notes were acquired as a result of market-making activities or other
trading activities. We and our subsidiary guarantors have agreed to make this
prospectus, as amended or supplemented, available to any broker-dealer for use
in connection with any such resale for a period of 180 days from the date of the
completion of the exchange offer, or such shorter period as will terminate when
all old Notes acquired by broker-dealers for their own accounts as a result of
market-making activities or other trading activities have been exchanged for new
Notes and resold by such broker-dealers.

    We will not receive any proceeds from any sale of new Notes by
broker-dealers. New Notes received by broker-dealers for their own accounts
pursuant to the exchange offer may be sold from time to time in one or more
transactions in the over-the-counter market or, in negotiated transactions or a
combination of such methods of resale, at market prices prevailing at the time
of resale, at prices related to such prevailing market prices or negotiated
prices. Any such resale may be made directly to purchasers or to or through
brokers or dealers who may receive compensation in the form of commissions or
concessions from any such broker-dealer and/or the purchasers of any such new
Notes. Any broker-dealer that resells new Notes that were received by it for its
own account pursuant to the exchange offer and any broker-dealer that
participates in a distribution of such new Notes may be deemed to be an
"underwriter" within the meaning of the Securities Act, and any profit on any
such resale of new Notes and any commissions or concessions received by any such
persons may be deemed to be underwriting compensation under the Securities Act.
The letter of transmittal states that by acknowledging that it will deliver, and
by delivering, a prospectus, a broker-dealer will not be deemed to admit that it
is an "underwriter" within the meaning of the Securities Act.

    For a period of 180 days from the date of this prospectus, or such shorter
period as will terminate when all old Notes acquired by broker-dealers for their
own accounts as a result of market-making activities or other trading activities
have been exchanged for new Notes and resold by such broker-dealers, we will
promptly send additional copies of this prospectus and any amendment or
supplement to this prospectus to any broker-dealer that requests such documents
in the letter of transmittal. We have agreed to indemnify such broker-dealers
against specific liabilities, including liabilities under the Securities Act.

                                       73

                             TRANSFER RESTRICTIONS

    Unless and until an old Note is exchanged for a new Note pursuant to the
exchange offer, it will continue to bear the following legend on the face
thereof:

    "These securities have not been registered under the United States
    Securities Act of 1933, as amended (the "Securities Act"), and these
    securities may not be offered, sold, pledged or otherwise transferred except
    pursuant to an exemption from the registration requirements of the
    Securities Act and, in each case, in accordance with any applicable
    securities laws of any state of the United States or any other jurisdiction.

    Each holder of this security by its acceptance hereof agrees to (a) offer,
    sell, pledge or otherwise transfer this security only (1) to Iron Mountain
    Incorporated, (2) pursuant to a registration statement which has been
    declared effective under the Securities Act, (3) to a person it reasonably
    believes is a "qualified institutional buyer" as defined in rule 144A in a
    transaction meeting the requirements of Rule 144A, (4) pursuant to offers
    and sales to non-U.S. persons that occur outside the United States in a
    transaction meeting the requirements of Rule 904 of Regulation S under the
    Securities Act, (5) to an institutional "accredited investor" (as defined in
    Rule 501(A)(1), (2), (3) or (7) of Regulation D under the Securities Act)
    (an "IAI") that, prior to such transfer, executes and delivers to Iron
    Mountain Incorporated and the Trustee a letter containing certain
    representations and agreements relating to the transfer of this security
    (the form of which letter can be obtained from the Trustee) and an opinion
    of counsel, if Iron Mountain Incorporated or the Trustee so requests, or (6)
    pursuant to any other available exemption from the registration requirements
    under the Securities Act (and based on an opinion of counsel if Iron
    Mountain incorporated so requests), subject in each of the foregoing cases
    to applicable securities laws of any state of the United States or any other
    applicable jurisdiction, and (b) that it will, and each subsequent holder is
    required to, notify any purchaser from it of this security of the resale
    restrictions set forth in (a) above."

    The new Notes will not contain such restrictive legend or be otherwise
subject to restrictions on their transfer, except each global note shall bear
the following legend on the face thereof:

    "Unless and until it is exchanged in whole or in part for notes in
    definitive form, this note may not be transferred except as a whole by the
    Depositary Trust Company (the "Depository") to a nominee of the Depository
    or by the Depository or any such nominee to the Depositary or another
    nominee of the Depositary or by the Depositary or any such nominee to a
    successor depositary or a nominee of such successor depositary. Unless this
    certificate is presented by an authorized representative of the depositary
    to Iron Mountain or our agent for registration or transfer, exchange or
    payment, and any certificate issued is registered in the name of Cede & Co.
    or such other name as may be requested by an authorized representative of
    Depositary (and any payment hereon is made to Cede & Co. or such other
    entity as may be requested by an authorized representative of Depositary),
    any transfer, pledge or other use hereof for value or otherwise by or to any
    person is wrongful inasmuch as the registered owner hereof, Cede & Co., has
    an interest herein."

                                 LEGAL MATTERS

    Certain legal matters with respect to the validity of the new Notes and the
Guarantees will be passed upon for Iron Mountain by Sullivan & Worcester LLP,
Boston, Massachusetts and for the Initial Purchasers by Latham & Watkins, New
York, New York. Jas. Murray Howe, Secretary of Iron Mountain, is of counsel to
Sullivan & Worcester LLP and beneficially owns 20,000 shares of Common Stock.

                                       74

                                    EXPERTS

    The consolidated financial statements of Iron Mountain Incorporated and its
subsidiaries for the three years ended December 31, 1998, included in Iron
Mountain's Current Report on Form 8-K dated July 9, 1999, and its supplemental
schedule, Valuation and Qualifying Accounts, included in its Annual Report on
Form 10-K dated March 31, 1999, have been audited by Arthur Andersen LLP,
independent public accountants, as indicated in their reports with respect
thereto, and are incorporated by reference herein in reliance upon the authority
of said firm as experts in giving said reports.

    The financial statements of Records Retention/FileSafe, L.P. for the two
years ended December 31, 1996, included in Iron Mountain's Current Report on
Form 8-K dated November 25, 1997, have been audited by Abbott, Stringham &
Lynch, independent public accountants, as indicated in their report with respect
thereto, and are incorporated by reference herein in reliance upon the authority
of said firm as experts in giving said report.

    The consolidated financial statements of HIMSCORP, Inc. and Subsidiaries for
the period February 1, 1995 to December 31, 1995 and for the year ended December
31, 1996, appearing in Iron Mountain's Current Reports on Form 8-K dated October
30, 1997 and November 25, 1997, have been audited by Ernst & Young LLP,
independent auditors, as indicated in their reports thereon included therein,
and are incorporated by reference herein in reliance upon such reports given
upon the authority of said firm as experts in accounting and auditing.

    The consolidated financial statements of Arcus Technology Services, Inc. for
each of the two years in the period ended December 31, 1997 and the five-month
period ended December 31, 1995 and the consolidated financial statements of
Arcus, Inc. (Predecessor Company) for the seven-month period ended July 31,
1995, appearing in Iron Mountain's Current Report on Form 8-K dated March 9,
1998, have been audited by Ernst & Young LLP, independent auditors, as indicated
in their report thereon included therein and are incorporated by reference
herein in reliance upon such report given upon the authority of said firm as
experts in accounting and auditing.

    The consolidated financial statements of Arcus Group, Inc. for each of the
two years in the period ended December 31, 1996, appearing in Iron Mountain's
Current Reports on Form 8-K dated October 30, 1997 and November 25, 1997, have
been audited by Ernst & Young LLP, independent auditors, as indicated in their
reports thereon included therein, and are incorporated by reference herein in
reliance upon such reports given upon the authority of said firm as experts in
accounting and auditing.

    The financial statements of Midwest Records Management for the year ended
December 31, 1997, included in Iron Mountain's Current Report on Form 8-K dated
September 18, 1998, have been audited by Arthur Andersen LLP, independent public
accountants, as indicated in their report with respect thereto, and are
incorporated by reference herein in reliance upon the authority of said firm as
experts in giving said report.

    The financial statements of Sloan Vaults, Inc. and Affiliate for the year
ended December 31, 1997, included in Iron Mountain's Current Report on Form 8-K
dated September 18, 1998, have been audited by Arthur Andersen LLP, independent
public accountants, as indicated in their report with respect thereto, and are
incorporated by reference herein in reliance upon the authority of said firm as
experts in giving said report.

    The financial statements of InterMation, Inc. for the year ended December
31, 1997, included in Iron Mountain's Current Report on Form 8-K dated September
18, 1998, have been audited by Arthur Andersen LLP, independent public
accountants, as indicated in their report with respect thereto, and are
incorporated by reference herein in reliance upon the authority of said firm as
experts in giving said report.

                                       75

    The financial statements of National Underground Storage, Inc. for the two
years ended December 31, 1997, included in Iron Mountain's Current Report on
Form 8-K/A dated August 7, 1998, have been audited by Carbis Walker &
Associates, LLP, independent public accountants, as indicated in their report
with respect thereto, and are incorporated by reference herein in reliance upon
the authority of said firm as experts in giving said report.

    The financial statements of Britannia Data Management Limited for the two
years ended October 31, 1998, included in Iron Mountain's Current Report on Form
8-K/A dated March 22, 1999, have been audited by Robson Rhodes, chartered
accountants, as indicated in their report with respect thereto, and are
incorporated by reference herein in reliance upon the authority of said firm as
experts in giving said report.

    The financial statements of Data Base, Inc. and Affiliate for the three
years ended December 31, 1998, included in Iron Mountain's Current Report on
Form 8-K dated April 16, 1999, have been audited by Moss Adams LLP, independent
public accountants, as indicated in their report with respect thereto, and are
incorporated by reference herein in reliance upon the authority of said firm as
experts in giving said report.

    The financial statements of First American Records Management, Inc. for the
year ended December 31, 1998, included in Iron Mountain's Current Report on Form
8-K dated July 9, 1999, have been audited by Brach, Neal, Daney & Spence, LLP,
independent public accountants, as indicated in their report with respect
thereto, and are incorporated by reference herein in reliance upon the authority
of said firm as experts in giving said report.

    The financial statements of MAP, S.A. for the year ended February 28, 1999,
included in Iron Mountain's Current Report on Form 8-K dated July 9, 1999, have
been audited by Barbier Frinault & Associes, independent public accountants, as
indicated in their report with respect thereto, and are incorporated by
reference herein in reliance upon the authority of said firm as experts in
giving said report.

                                       76

                                    PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 20. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

    Section 145 of the Delaware General Corporation Law (the "DGCL") provides,
in effect, that any person made a party to any action by reason of the fact that
he is or was a director, officer, employee or agent of Iron Mountain may and, in
certain cases, must be indemnified by Iron Mountain against, in the case of a
non-derivative action, judgments, fines, amounts paid in settlement and
reasonable expenses (including attorney's fees) incurred by him as a result of
such action, and in the case of a derivative action, against expenses (including
attorney's fees), if in either type of action he acted in good faith and in a
manner he reasonably believed to be in, or not opposed to, the best interests of
Iron Mountain. This indemnification does not apply, in a derivative action, to
matters as to which it is adjudged that the director, officer, employee or agent
is liable to Iron Mountain, unless upon court order it is determined that,
despite such adjudication of liability, but in view of all the circumstances of
the case, he is fairly and reasonably entitled to indemnity for expenses, and,
in a non-derivative action, to any criminal proceeding in which such person had
reasonable cause to believe his conduct was unlawful.

    Article Sixth of Iron Mountain's Restated Certificate of Incorporation
provides that Iron Mountain shall indemnify each person who is or was an officer
or director of Iron Mountain to the fullest extent permitted by Section 145 of
the DGCL.

    Article Seventh of Iron Mountain's Restated Certificate of Incorporation
states that no director of Iron Mountain shall be liable to Iron Mountain or its
stockholders for monetary damages for breach of fiduciary duty as a director,
except to the extent that exculpation from liability is not permitted under the
DGCL as in effect when such breach occurred.

ITEM 21. EXHIBITS

    Exhibits indicated below are incorporated by reference to documents of the
Company on file with the Commission. Exhibit numbers in parentheses refer to the
Exhibit numbers in the applicable filing (which are identified in the footnotes
appearing at the end of this index). All other exhibits are filed herewith.



EXHIBIT NO.                                            ITEM                                              EXHIBIT
- -------------  ------------------------------------------------------------------------------------  ---------------
                                                                                               

       2.1     Agreement and Plan of Merger, dated as of September 26, 1997, by and among Iron          (2.2)(6)
               Mountain, Arcus Group, United Acquisition Company and Arcus Technology Services,
               Inc. (collectively, the "Arcus Parties")

       2.2     Amendment No. 1 to Agreement and Plan of Merger, dated as of November 25, 1997, by       (2.1A)(8)
               and among Iron Mountain and each of the Arcus Parties

       2.3     Agreement and Plan of Merger, dated as of February 19, 1997, by and among Iron            (2)(3)
               Mountain, IM-1 Acquisition Corp. and Safesite Records Management Corporation
               ("Safesite")

       2.4     Amendment No. 1 to Agreement and Plan of Merger, dated as of April 1, 1997, by and        (2A)(4)
               among Iron Mountain, IM-1 Acquisition Corp. and Safesite

       2.5     Amendment No. 2 to Agreement and Plan of Merger, dated as of May 7, 1997, by and          (2B)(4)
               among Iron Mountain, IM-1 Acquisition Corp. and Safesite


                                      II-1



EXHIBIT NO.                                            ITEM                                              EXHIBIT
- -------------  ------------------------------------------------------------------------------------  ---------------
                                                                                               
       2.6     Agreement and Plan of Merger, dated as of August 25, 1997, by and among Iron             (2.3)(6)
               Mountain, DSI Acquisition Corporation and Data Securities International, Inc.

       2.7     Agreement and Plan of Merger, dated as of September 17, 1997, by and among Iron          (2.2)(7)
               Mountain, IM-3 Acquisition Corp. and HIMSCORP, Inc.

       2.8     Agreement and Plan of Merger, dated as of February 24, 1998, by and among Iron           (2.7)(11)
               Mountain, IM-3 Acquisition Corp. and InterMation, Inc. (confidential treatment
               granted as to certain portions)

       2.9     Agreement and Plan of Merger, dated as of June 5, 1998, by and among Iron Mountain       (2.1)(12)
               Records Management, Inc. ("IMRM"), Iron Mountain/ NUS, Inc. and National Underground
               Storage, Inc. (confidential treatment granted as to certain portions)

       2.10    Stock Purchase Agreement, dated as of February 28, 1999, by and among Iron Mountain,    (2.10)(16)
               Data Base, Inc. ("Data Base") and all of the stockholders of Data Base (confidential
               treatment granted as to certain portions)

       2.11    First Amendment to Stock Purchase Agreement, dated as of April 8, 1999, by and among    (10.1)(17)
               Iron Mountain, Data Base and all of the stockholders of Data Base

       2.12    Stock Purchase Agreement, dated as of April 1, 1999, by and among IMRM, First            (2.2)(17)
               American Records Management, Inc. and all of the stockholders of First American
               Records Management, Inc. (portions of this exhibit have been omitted pursuant to a
               request for confidential treatment)

       3.1     Amended and Restated Certificate of Incorporation of Iron Mountain, as amended           (3.1)(9)

       3.2     Amended and Restated By-Laws of Iron Mountain, as amended                                (3.2)(9)

       4.1     Indenture for 8 1/4% Senior Subordinated Notes due 2011, dated April 26, 1999, by       (10.1)(18)
               and among Iron Mountain, certain of its subsidiaries and The Bank of New York, as
               trustee

       4.2     Exchange and Registration Rights Agreement, dated as of April 26, 1999, by and among    (10.1)(18)
               Iron Mountain, certain of its subsidiaries and Bear, Stearns & Co. Inc., Chase
               Securities Inc., BNY Capital Markets, Inc., Fleet Securities, Inc., Prudential
               Securities Incorporated and Scotia Capital Markets (USA) Inc., as initial purchasers

       5       Opinion of Sullivan & Worcester LLP, as to the legality of the securities             Filed herewith
                                                                                                      as Exhibit 5

      10.1     Second Amended and Restated Credit Agreement, dated as of September 26, 1997, among      (10.1)(6)
               Iron Mountain, the lenders party thereto and The Chase Manhattan Bank, as
               Administrative Agent

      10.2     Amendment No. 1 to the Second Amended and Restated Credit Agreement, dated as of        (10.1)(13)
               December 31, 1997, among Iron Mountain, the lenders party thereto and The Chase
               Manhattan Bank, as Administrative Agent


                                      II-2



EXHIBIT NO.                                            ITEM                                              EXHIBIT
- -------------  ------------------------------------------------------------------------------------  ---------------
                                                                                               
      10.3     Amendment No. 2 to the Second Amended and Restated Credit Agreement, dated as of        (10.1)(15)
               November 9, 1998, among Iron Mountain, the lenders party thereto and The Chase
               Manhattan Bank, as Administrative Agent

      10.4     Indenture for 10 1/8% Senior Subordinated Notes due 2006, dated October 1, 1996, by      (10.3)(3)
               and among Iron Mountain, certain of its subsidiaries and First National Association,
               as trustee

      10.5     Indenture of 8 3/4% Senior Subordinated Notes due 2009, dated October 24, 1997, by       (4.1)(5)
               and among Iron Mountain, certain of its subsidiaries and The Bank of New York, as
               trustee

      10.6     Iron Mountain Incorporated 1995 Stock Incentive Plan, as amended                        (10.1)(17)

      10.7     Iron Mountain/UAC 1995 Stock Option Plan                                                (10.1)(10)

      10.8     Iron Mountain/ATSI 1995 Stock Option Plan                                               (10.2)(10)

      10.9     Iron Mountain Incorporated 1998 Employee Stock Purchase Plan                            (10.8)(13)

      10.10    Record Center Storage Services Agreement between IMRM and Resolution Trust              (10.18)(1)
               Corporation, dated July 31, 1992, as renewed by letter agreement effective July 26,
               1998 between Iron Mountain and the Federal Deposit Insurance Corporation

      10.11    Amended and Restated Registration Rights Agreement, dated as of June 12, 1997,           (10.2)(6)
               between Iron Mountain and certain stockholders of Iron Mountain

      10.12    Joinder to Registration Rights Agreement, dated as of October 31, 1997, by and          (10.12)(8)
               between Iron Mountain and Kent P. Dauten

      10.13    Stockholders' Agreement, dated September 17, 1997, by and between Iron Mountain and     (10.13)(9)
               Kent P. Dauten

      10.14    Stockholders' Agreement, dated as of February 19, 1997, by and among Iron Mountain      (10.20)(3)
               and certain stockholders of Safesite

      10.15    Asset Purchase and Sale Agreement, dated as of August 20, 1997, by and between IMRM      (10.2)(6)
               and Records Retention/FileSafe, L.P.

      10.16    Stockholders' Agreement, dated as of September 26, 1997, by and among Iron Mountain     (10.16)(8)
               and certain stockholders of the Arcus Parties

      10.17    Lease Agreement, dated as of October 1, 1998, between Iron Mountain Statutory           (10.20)(14)
               Trust--1998 and IMRM

      10.18    Unconditional Guaranty, dated as of October 1, 1998, from Iron Mountain to Iron         (10.21)(14)
               Mountain Statutory Trust--1998

      10.19    Amended and Restated Agency Agreement, dated October 1, 1998, by and between Iron       (10.22)(14)
               Mountain Statutory Trust--1998 and IMRM

      10.20    Amendment and Agreement Re: Leasehold Improvements, dated as of January 28, 1999, by    (10.22)(16)
               and among Iron Mountain Statutory Trust--1998, First Union National Bank, Scotiabanc
               Inc., IMRM, Iron Mountain, the lenders party thereto, The Bank of Nova Scotia, as
               Agent for the lenders, and BTM Capital Corporation, as LC Issuer

      10.21    Agreement, dated as of December 2, 1998, by and between Iron Mountain and Mentmore       (2.1)(15)
               Abbey plc


                                      II-3



EXHIBIT NO.                                            ITEM                                              EXHIBIT
- -------------  ------------------------------------------------------------------------------------  ---------------
                                                                                               
      10.22    Strategic Alliance Agreement, dated as of January 4, 1999, by and among Iron            (10.2)(15)
               Mountain, Iron Mountain (U.K.) Limited, Britannia Data Management Limited and
               Mentmore Abbey plc

      12       Statement of the computation of ratio of earnings to fixed charges                    Filed herewith
                                                                                                      as Exhibit 12

      21       Subsidiaries of Iron Mountain                                                         Filed herewith
                                                                                                      as Exhibit 21

      23.1     Consent of Arthur Andersen LLP (Iron Mountain Incorporated and its subsidiaries)      Filed herewith
                                                                                                     as Exhibit 23.1

      23.2     Consent of Abbott, Stringham & Lynch (Records Retention/File Safe, L.P.)              Filed herewith
                                                                                                     as Exhibit 23.2

      23.3     Consent of Ernst & Young LLP (HIMSCORP, Inc. and Subsidiaries)                        Filed herewith
                                                                                                     as Exhibit 23.3

      23.4     Consent of Ernst & Young LLP (Arcus Technology Services, Inc.)                        Filed herewith
                                                                                                     as Exhibit 23.4

      23.5     Consent of Arthur Andersen LLP (Midwest Records Management, Sloan Vaults, Inc. and    Filed herewith
               Affiliate, and InterMation, Inc.)                                                     as Exhibit 23.5

      23.6     Consent of Carbis Walker & Associates, LLP (National Underground Storage, Inc.)       Filed herewith
                                                                                                     as Exhibit 23.6

      23.7     Consent of Robson Rhodes (Britannia Data Management Limited)                          Filed herewith
                                                                                                     as Exhibit 23.7

      23.8     Consent of Moss Adams LLP (Data Base, Inc. and Affiliate)                             Filed herewith
                                                                                                     as Exhibit 23.8

      23.9     Consent of Brach, Neal, Daney & Spence, LLP (First American Records Management,       Filed herewith
               Inc.)                                                                                 as Exhibit 23.9

      23.10    Consent of Barbier Frinault & Associes (MAP, S.A.)                                    Filed herewith
                                                                                                       as Exhibit
                                                                                                          23.10

      24       Powers of Attorney                                                                     Contained on
                                                                                                       Pages II-8,
                                                                                                     II-10 and II-11
                                                                                                         of the
                                                                                                      Registration
                                                                                                        Statement


                                      II-4



EXHIBIT NO.                                            ITEM                                              EXHIBIT
- -------------  ------------------------------------------------------------------------------------  ---------------
                                                                                               
      25       Form T-1 Statement of Eligibility of The Bank of New York                             Filed herewith
                                                                                                      as Exhibit 25

      27       Financial Data Schedule--March 31, 1999                                                  (27)(19)

      99.1     Form of Letter of Transmittal                                                         Filed herewith
                                                                                                     as Exhibit 99.1

      99.2     Form of Notice of Guaranteed Delivery                                                 Filed herewith
                                                                                                     as Exhibit 99.2


- ------------------------

1.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 33-99950,
    filed with the Commission on December 1, 1995.

2.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-10359,
    filed with the Commission on August 16, 1996.

3.  Filed as an Exhibit to Iron Mountain's Annual Report on Form 10-K for the
    year ended December 31, 1996, filed with the Commission, File No. 0-27584.

4.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-24635,
    filed with the Commission on April 4, 1997, as amended on May 7, 1997 and
    May 13, 1997.

5.  Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated
    October 30, 1997, filed with the Commission, File No. 0-27584.

6.  Filed as an Exhibit to Iron Mountain's Quarterly Report on Form 10-Q for the
    quarter ended September 30, 1997, filed with the Commission, File No.
    0-27584.

7.  Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K/A dated
    November 10, 1997, filed with the Commission, File No. 0-27584.

8.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-41045,
    filed with the Commission on November 26, 1997.

9.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-44185,
    filed with the Commission on January 13, 1998.

10. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated
    March 9, 1998, filed with the Commission, File No. 0-27584.

11. Filed as an Exhibit to Iron Mountain's Annual Report on Form 10-K for the
    year ended December 31, 1997, filed with the Commission, File No. 0-27584.

12. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated July
    10, 1998, filed with the Commission, File No. 0-27584.

13. Filed as an Exhibit to Amendment No. 1 to Iron Mountain's Registration
    Statement No. 333-44187, filed with the Commission on August 3, 1998.

14. Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-67765,
    filed with the Commission on November 23, 1998.

15. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated
    January 19, 1999, filed with the Commission, File No. 0-27584.

                                      II-5

16. Filed as an Exhibit to Iron Mountain's Annual Report on Form 10-K for the
    year ended December 31, 1998, filed with the Commission, File No. 0-27584.

17. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated
    April 16, 1999, filed with the Commission, File No. 0-27584.

18. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated May
    11, 1999, filed with the Commission, File No. 0-27584.

19. Filed as an Exhibit to Iron Mountain's Quarterly Report on Form 10-Q for the
    quarter ended March 31, 1999, filed with the Commission, File No. 0-27584.

ITEM 22. UNDERTAKINGS

    The undersigned Registrant hereby undertakes:

    (1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this Registration Statement:

        (i) To include any prospectus required by Section 10(a)(3) of the
    Securities Act of 1933, as amended (the "Securities Act");

        (ii) To reflect in the prospectus any facts or events arising after the
    effective date of this Registration Statement (or the most recent
    post-effective amendment thereof) which, individually or in the aggregate,
    represent a fundamental change in the information set forth in this
    Registration Statement. Notwithstanding the foregoing, any increase or
    decrease in volume of securities offered (if the total dollar value of
    securities offered would not exceed that which was registered) and any
    deviation from the low or high end of the estimated maximum offering range
    may be reflected in the form of prospectus filed with the Commission
    pursuant to Rule 424(b) if, in the aggregate, the changes in volume and
    price represent no more than 20 percent change in the maximum aggregate
    offering price set forth in the "Calculation of Registration Fee" table in
    the effective Registration Statement;

        (iii) To include any material information with respect to the plan of
    distribution not previously disclosed in the Registration Statement or any
    material change to such information in the Registration Statement;

PROVIDED, HOWEVER, that the undertakings set forth in paragraphs (1)(i) and
(1)(ii) above do not apply if the information required to be included in a
post-effective amendment by those paragraphs is contained in periodic reports
filed with or furnished to the Commission by the Registrant pursuant to Section
13 or Section 15(d) of the Securities Exchange Act of 1934, as amended (the
"Exchange Act") that are incorporated by reference in this Registration
Statement.

    (2) That, for the purpose of determining any liability under the Securities
Act, each such post-effective amendment shall be deemed to be a new Registration
Statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial BONA FIDE offering
thereof;

    (3) To remove from registration by means of a post-effective amendment any
of the securities being registered which remain unsold at the termination of the
offering;

    (4) That, for purposes of determining any liability under the Securities
Act, each filing of the Registrant's Annual Report pursuant to Section 13(a) or
Section 15(d) of the Exchange Act (and where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the Exchange
Act) that is incorporated by reference in this Registration Statement shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial BONA FIDE offering thereof;

                                      II-6

    (5) That prior to any public reoffering of the securities registered
hereunder through use of a prospectus which is a part of this Registration
Statement, by any person or party who is deemed to be an underwriter within the
meaning of Rule 145(c), the Registrant undertakes that such reoffering
prospectus will contain the information called for by the applicable
registration form with respect to reofferings by persons who may be deemed
underwriters, in addition to the information called for by the other items of
the applicable form;

    (6) That every prospectus: (i) that is filed pursuant to paragraph (5)
immediately preceding, or (ii) that purports to meet the requirements of Section
10(a)(3) of the Securities Act and is used in connection with an offering of
securities subject to Rule 415, will be filed as a part of an amendment to the
Registration Statement and will not be used until such amendment is effective,
and that, for purposes of determining any liability under the Securities Act,
each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial BONA FIDE offering
thereof;

    (7) To respond to requests for information that is incorporated by reference
into the prospectus pursuant to Item 4, 10(b), 11 or 13 of this form, within one
business day of receipt of such request, and to send the incorporated documents
by first class mail or other equally prompt means. This includes information
contained in documents filed subsequent to the effective date of this
Registration Statement through the date of responding to the request;

    (8) To supply by means of a post-effective amendment all information
concerning a transaction, and the company being acquired involved therein, that
was not the subject of and included in the Registration Statement when it became
effective;

    (9) Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the foregoing provisions, or otherwise, the Registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.

                                      II-7

                                   SIGNATURES

    Pursuant to the requirements of the Securities Act, the Registrant has duly
caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Boston, Commonwealth of
Massachusetts, on July 9, 1999.

                               
                                IRON MOUNTAIN INCORPORATED

                                By:  /s/ C. RICHARD REESE
                                     -----------------------------------------
                                     Name: C. Richard Reese
                                     Title: Chairman of the Board of Directors
                                     and Chief Executive Officer



    Pursuant to the requirements of the Securities Act, this Registration
Statement on Form S-4 relating to the new Notes has been signed below on July 9,
1999 by the following persons in the capacities and on the dates indicated; and
each of the undersigned officers and directors of Iron Mountain Incorporated
hereby severally constitutes and appoints C. Richard Reese, David S. Wendell and
John F. Kenny, Jr., and each of them, to sign for him, and in his name in the
capacity indicated below, such Registration Statement for the purpose of
registering such securities under the Securities Act, and any and all amendments
thereto, including without limitation any registration statement or
post-effective amendment thereof filed under and meeting the requirements of
Rule 462(b) under the Securities Act, hereby ratifying and confirming our
signatures as they may be signed by our attorneys to such Registration Statement
and any and all amendments thereto.



          SIGNATURE                       TITLE                    DATE
- ------------------------------  --------------------------  -------------------

                                                      
     /s/ C. RICHARD REESE       Chairman of the Board of
- ------------------------------    Directors and Chief          July 9, 1999
       C. Richard Reese           Executive Officer

     /s/ DAVID S. WENDELL
- ------------------------------  President, Chief Operating     July 9, 1999
       David S. Wendell           Officer and Director

    /s/ JOHN F. KENNY, JR.      Executive Vice President
- ------------------------------    and Chief Financial          July 9, 1999
      John F. Kenny, Jr.          Officer

     /s/ CLARKE H. BAILEY
- ------------------------------  Director                       July 9, 1999
       Clarke H. Bailey

   /s/ CONSTANTIN R. BODEN
- ------------------------------  Director                       July 9, 1999
     Constantin R. Boden


                                      II-8



          SIGNATURE                       TITLE                    DATE
- ------------------------------  --------------------------  -------------------

                                                      
      /s/ KENT P. DAUTEN
- ------------------------------  Director                       July 9, 1999
        Kent P. Dauten

    /s/ EUGENE B. DOGGETT
- ------------------------------  Director                       July 9, 1999
      Eugene B. Doggett

    /s/ B. THOMAS GOLISANO
- ------------------------------  Director                       July 9, 1999
      B. Thomas Golisano

     /s/ ARTHUR D. LITTLE
- ------------------------------  Director                       July 9, 1999
       Arthur D. Little

     /s/ VINCENT J. RYAN
- ------------------------------  Director                       July 9, 1999
       Vincent J. Ryan

                                Vice President and
       /s/ JEAN A. BUA            Corporate Controller
- ------------------------------    (principal accounting        July 9, 1999
         Jean A. Bua              officer)


                                      II-9

                                   SIGNATURES

    Pursuant to the requirements of the Securities Act of 1933, Arcus Data
Security, Inc., Arcus Data Security LLC, Arcus Staffing Resources, Inc., Carter
Media Management, Inc., Criterion Atlantic Property, Inc., Datavault/United
States Safe Deposit Company, DSI Technology Escrow Services, Inc., HIMSCORP of
Cleveland, Inc., HIMSCORP of Detroit, Inc., HIMSCORP of Houston, Inc., HIMSCORP
of Los Angeles, Inc., HIMSCORP of New Orleans, Inc., HIMSCORP of Philadelphia,
Inc., HIMSCORP of Pittsburgh, Inc., HIMSCORP of Portland, Inc., HIMSCORP of San
Diego, Inc., IM-AEI Acquisition Corp., IM Billerica, Inc., Iron Mountain
Consulting Services, Inc., Iron Mountain of Maryland LLC, Iron Mountain/National
Underground Storage, Inc., Iron Mountain Records Management, Inc., Iron Mountain
Records Management of Michigan, Inc., Iron Mountain Records Management of Ohio,
Inc., Iron Mountain Records Management of San Antonio, Inc., Iron Mountain
Records Management of San Antonio--FP, Inc., Iron Mountain Records Management of
Utah, Inc., Iron Mountain Safe Deposit Corporation, Iron Mountain/Safesite,
Inc., and Recordkeepers, Inc., have each duly caused this Registration Statement
to be signed on its behalf by the undersigned, thereunto duly authorized, in the
City of Boston, Commonwealth of Massachusetts, on July 9, 1999.

ARCUS DATA SECURITY, INC.
ARCUS STAFFING RESOURCES, INC.
CARTER MEDIA MANAGEMENT, INC.
CRITERION ATLANTIC PROPERTY, INC.
DATAVAULT/UNITED STATES SAFE DEPOSIT COMPANY
DSI TECHNOLOGY ESCROW SERVICES, INC.
HIMSCORP OF CLEVELAND, INC.
HIMSCORP OF DETROIT, INC.
HIMSCORP OF HOUSTON, INC.
HIMSCORP OF LOS ANGELES, INC.
HIMSCORP OF NEW ORLEANS, INC.
HIMSCORP OF PHILADELPHIA, INC.
HIMSCORP OF PITTSBURGH, INC.
HIMSCORP OF PORTLAND, INC.
HIMSCORP OF SAN DIEGO, INC.
IM-AEI ACQUISITION CORP.
IM BILLERICA, INC.
IRON MOUNTAIN CONSULTING SERVICES, INC.
IRON MOUNTAIN/NATIONAL UNDERGROUND STORAGE, INC.
IRON MOUNTAIN RECORDS MANAGEMENT, INC.
IRON MOUNTAIN RECORDS MANAGEMENT OF MICHIGAN, INC.
IRON MOUNTAIN RECORDS MANAGEMENT OF OHIO, INC.
IRON MOUNTAIN RECORDS MANAGEMENT OF SAN ANTONIO, INC.
IRON MOUNTAIN RECORDS MANAGEMENT OF SAN ANTONIO--FP, INC.
IRON MOUNTAIN RECORDS MANAGEMENT OF UTAH, INC.
IRON MOUNTAIN SAFE DEPOSIT CORPORATION
IRON MOUNTAIN/SAFESITE, INC.
RECORDKEEPERS, INC.

                               
                                By:  /s/ C. RICHARD REESE
                                     -----------------------------------------
                                     Name: C. Richard Reese
                                     Title: Chairman of the Board of Directors
                                     and Chief Executive Officer

                                ARCUS DATA SECURITY LLC
                                IRON MOUNTAIN OF MARYLAND LLC

                                By:  Iron Mountain Records Management, Inc.
                                     Its Manager

                                By:  /s/ C. RICHARD REESE
                                     -----------------------------------------
                                     Name: C. Richard Reese
                                     Title: Chairman of the Board of Directors
                                     and Chief Executive Officer



                                     II-10

    Pursuant to the requirements of the Securities Act, this Registration
Statement on Form S-4 relating to the New Notes has been signed below on July 9,
1999 by the following persons in the capacities and on the dates indicated; and
each of the undersigned officers or directors or managers of Arcus Data
Security, Inc., Arcus Data Security LLC, Arcus Staffing Resources, Inc., Carter
Media Management, Inc., Criterion Atlantic Property, Inc., Datavault/United
States Safe Deposit Company, DSI Technology Escrow Services, Inc., HIMSCORP of
Cleveland, Inc., HIMSCORP of Detroit, Inc., HIMSCORP of Houston, Inc., HIMSCORP
of Los Angeles, Inc., HIMSCORP of New Orleans, Inc., HIMSCORP of Philadelphia,
Inc., HIMSCORP of Pittsburgh, Inc., HIMSCORP of Portland, Inc., HIMSCORP of San
Diego, Inc., IM-AEI Acquisition Corp., IM Billerica, Inc., Iron Mountain
Consulting Services, Inc., Iron Mountain of Maryland LLC, Iron Mountain/National
Underground Storage, Inc., Iron Mountain Records Management, Inc., Iron Mountain
Records Management of Michigan, Inc., Iron Mountain Records Management of Ohio,
Inc., Iron Mountain Records Management of San Antonio, Inc., Iron Mountain
Records Management of San Antonio--FP, Inc., Iron Mountain Records Management of
Utah, Inc., Iron Mountain Safe Deposit Corporation, Iron Mountain/Safesite,
Inc., and Recordkeepers, Inc., hereby severally constitutes and appoints C.
Richard Reese, David S. Wendell and John F. Kenny, Jr., and each of them, to
sign for him, and in his name in the capacity indicated below, such Registration
Statement for the purpose of registering such securities under the Securities
Act, and any and all amendments thereto, including without limitation any
registration statement or post-effective amendment thereof filed under and
meeting the requirements of Rule 462(b) under the Securities Act, hereby
ratifying and confirming our signatures as they may be signed by our attorneys
to such Registration Statement and any and all amendments thereto.



          SIGNATURE                       TITLE                    DATE
- ------------------------------  --------------------------  -------------------

                                                      
     /s/ C. RICHARD REESE       Chairman of the Board of
- ------------------------------    Directors and Chief          July 9, 1999
       C. Richard Reese           Executive Officer

    /s/ JOHN F. KENNY, JR.      Executive Vice President
- ------------------------------    and Chief Financial          July 9, 1999
      John F. Kenny, Jr.          Officer

                                Vice President and
         /s/ JEAN BUA             Corporate Controller
- ------------------------------    (principal accounting        July 9, 1999
           Jean Bua               officer)

                                Manager of Arcus Data
Iron Mountain Records             Security LLC and of Iron     July 9, 1999
Management, Inc.                  Mountain of Maryland LLC

By: /s/ C. RICHARD REESE
- ------------------------------
   Name: C. Richard Reese
   Title: Chairman of the
          Board of Directors
          and Chief Executive
          Officer


                                     II-11

                                 EXHIBIT INDEX



EXHIBIT NO.                                                                                              EXHIBIT
- -------------                                                                                        ---------------
                                                                                               

       2.1     Agreement and Plan of Merger, dated as of September 26, 1997, by and among Iron          (2.2)(6)
               Mountain, Arcus Group, United Acquisition Company and Arcus Technology Services,
               Inc. (collectively, the "Arcus Parties")

       2.2     Amendment No. 1 to Agreement and Plan of Merger, dated as of November 25, 1997, by       (2.1A)(8)
               and among Iron Mountain and each of the Arcus Parties

       2.3     Agreement and Plan of Merger, dated as of February 19, 1997, by and among Iron            (2)(3)
               Mountain, IM-1 Acquisition Corp. and Safesite Records Management Corporation
               ("Safesite")

       2.4     Amendment No. 1 to Agreement and Plan of Merger, dated as of April 1, 1997, by and        (2A)(4)
               among Iron Mountain, IM-1 Acquisition Corp. and Safesite

       2.5     Amendment No. 2 to Agreement and Plan of Merger, dated as of May 7, 1997, by and          (2B)(4)
               among Iron Mountain, IM-1 Acquisition Corp. and Safesite

       2.6     Agreement and Plan of Merger, dated as of August 25, 1997, by and among Iron             (2.3)(6)
               Mountain, DSI Acquisition Corporation and Data Securities International, Inc.

       2.7     Agreement and Plan of Merger, dated as of September 17, 1997, by and among Iron          (2.2)(7)
               Mountain, IM-3 Acquisition Corp. and HIMSCORP, Inc.

       2.8     Agreement and Plan of Merger, dated as of February 24, 1998, by and among Iron           (2.7)(11)
               Mountain, IM-3 Acquisition Corp. and InterMation, Inc. (confidential treatment
               granted as to certain portions)

       2.9     Agreement and Plan of Merger, dated as of June 5, 1998, by and among Iron Mountain       (2.1)(12)
               Records Management, Inc. ("IMRM"), Iron Mountain/ NUS, Inc. and National Underground
               Storage, Inc. (confidential treatment granted as to certain portions)

       2.10    Stock Purchase Agreement, dated as of February 28, 1999, by and among Iron Mountain,    (2.10)(16)
               Data Base, Inc. ("Data Base") and all of the stockholders of Data Base (confidential
               treatment granted as to certain portions)

       2.11    First Amendment to Stock Purchase Agreement, dated as of April 8, 1999, by and among    (10.1)(17)
               Iron Mountain, Data Base and all of the stockholders of Data Base

       2.12    Stock Purchase Agreement, dated as of April 1, 1999, by and among IMRM, First            (2.2)(17)
               American Records Management, Inc. and all of the stockholders of First American
               Records Management, Inc. (portions of this exhibit have been omitted pursuant to a
               request for confidential treatment)

       3.1     Amended and Restated Certificate of Incorporation of Iron Mountain, as amended           (3.1)(9)

       3.2     Amended and Restated By-Laws of Iron Mountain, as amended                                (3.2)(9)

       4.1     Indenture for 8 1/4% Senior Subordinated Notes due 2011, dated April 26, 1999, by       (10.1)(18)
               and among Iron Mountain, certain of its subsidiaries and The Bank of New York, as
               trustee

       4.2     Exchange and Registration Rights Agreement, dated as of April 26, 1999, by and among    (10.1)(18)
               Iron Mountain, certain of its subsidiaries and Bear, Stearns & Co. Inc., Chase
               Securities Inc., BNY Capital Markets, Inc., Fleet Securities, Inc., Prudential
               Securities Incorporated and Scotia Capital Markets (USA) Inc., as initial purchasers




EXHIBIT NO.                                                                                              EXHIBIT
- -------------                                                                                        ---------------
                                                                                               
       5       Opinion of Sullivan & Worcester LLP, as to the legality of the securities             Filed herewith
                                                                                                      as Exhibit 5

      10.1     Second Amended and Restated Credit Agreement, dated as of September 26, 1997, among      (10.1)(6)
               Iron Mountain, the lenders party thereto and The Chase Manhattan Bank, as
               Administrative Agent

      10.2     Amendment No. 1 to the Second Amended and Restated Credit Agreement, dated as of        (10.1)(13)
               December 31, 1997, among Iron Mountain, the lenders party thereto and The Chase
               Manhattan Bank, as Administrative Agent

      10.3     Amendment No. 2 to the Second Amended and Restated Credit Agreement, dated as of        (10.1)(15)
               November 9, 1998, among Iron Mountain, the lenders party thereto and The Chase
               Manhattan Bank, as Administrative Agent

      10.4     Indenture for 10 1/8% Senior Subordinated Notes due 2006, dated October 1, 1996, by      (10.3)(3)
               and among Iron Mountain, certain of its subsidiaries and First National Association,
               as trustee

      10.5     Indenture of 8 3/4% Senior Subordinated Notes due 2009, dated October 24, 1997, by       (4.1)(5)
               and among Iron Mountain, certain of its subsidiaries and The Bank of New York, as
               trustee

      10.6     Iron Mountain Incorporated 1995 Stock Incentive Plan, as amended                        (10.1)(17)

      10.7     Iron Mountain/UAC 1995 Stock Option Plan                                                (10.1)(10)

      10.8     Iron Mountain/ATSI 1995 Stock Option Plan                                               (10.2)(10)

      10.9     Iron Mountain Incorporated 1998 Employee Stock Purchase Plan                            (10.8)(13)

      10.10    Record Center Storage Services Agreement between IMRM and Resolution Trust              (10.18)(1)
               Corporation, dated July 31, 1992, as renewed by letter agreement effective July 26,
               1998 between Iron Mountain and the Federal Deposit Insurance Corporation

      10.11    Amended and Restated Registration Rights Agreement, dated as of June 12, 1997,           (10.2)(6)
               between Iron Mountain and certain stockholders of Iron Mountain

      10.12    Joinder to Registration Rights Agreement, dated as of October 31, 1997, by and          (10.12)(8)
               between Iron Mountain and Kent P. Dauten

      10.13    Stockholders' Agreement, dated September 17, 1997, by and between Iron Mountain and     (10.13)(9)
               Kent P. Dauten

      10.14    Stockholders' Agreement, dated as of February 19, 1997, by and among Iron Mountain      (10.20)(3)
               and certain stockholders of Safesite

      10.15    Asset Purchase and Sale Agreement, dated as of August 20, 1997, by and between IMRM      (10.2)(6)
               and Records Retention/FileSafe, L.P.

      10.16    Stockholders' Agreement, dated as of September 26, 1997, by and among Iron Mountain     (10.16)(8)
               and certain stockholders of the Arcus Parties

      10.17    Lease Agreement, dated as of October 1, 1998, between Iron Mountain Statutory           (10.20)(14)
               Trust--1998 and IMRM

      10.18    Unconditional Guaranty, dated as of October 1, 1998, from Iron Mountain to Iron         (10.21)(14)
               Mountain Statutory Trust--1998

      10.19    Amended and Restated Agency Agreement, dated October 1, 1998, by and between Iron       (10.22)(14)
               Mountain Statutory Trust--1998 and IMRM




EXHIBIT NO.                                                                                              EXHIBIT
- -------------                                                                                        ---------------
                                                                                               
      10.20    Amendment and Agreement Re: Leasehold Improvements, dated as of January 28, 1999, by    (10.22)(16)
               and among Iron Mountain Statutory Trust--1998, First Union National Bank, Scotiabanc
               Inc., IMRM, Iron Mountain, the lenders party thereto, The Bank of Nova Scotia, as
               Agent for the lenders, and BTM Capital Corporation, as LC Issuer

      10.21    Agreement, dated as of December 2, 1998, by and between Iron Mountain and Mentmore       (2.1)(15)
               Abbey plc

      10.22    Strategic Alliance Agreement, dated as of January 4, 1999, by and among Iron            (10.2)(15)
               Mountain, Iron Mountain (U.K.) Limited, Britannia Data Management Limited and
               Mentmore Abbey plc

      12       Statement of the computation of ratio of earnings to fixed charges                    Filed herewith
                                                                                                      as Exhibit 12

      21       Subsidiaries of Iron Mountain                                                         Filed herewith
                                                                                                      as Exhibit 21

      23.1     Consent of Arthur Andersen LLP (Iron Mountain Incorporated and its subsidiaries)      Filed herewith
                                                                                                     as Exhibit 23.1

      23.2     Consent of Abbott, Stringham & Lynch (Records Retention/File Safe, L.P.)              Filed herewith
                                                                                                     as Exhibit 23.2

      23.3     Consent of Ernst & Young LLP (HIMSCORP, Inc. and Subsidiaries)                        Filed herewith
                                                                                                     as Exhibit 23.3

      23.4     Consent of Ernst & Young LLP (Arcus Technology Services, Inc.)                        Filed herewith
                                                                                                     as Exhibit 23.4

      23.5     Consent of Arthur Andersen LLP (Midwest Records Management, Sloan Vaults, Inc. and    Filed herewith
               Affiliate, and InterMation, Inc.)                                                     as Exhibit 23.5

      23.6     Consent of Carbis Walker & Associates, LLP (National Underground Storage, Inc.)       Filed herewith
                                                                                                     as Exhibit 23.6

      23.7     Consent of Robson Rhodes (Britannia Data Management Limited)                          Filed herewith
                                                                                                     as Exhibit 23.7

      23.8     Consent of Moss Adams LLP (Data Base, Inc. and Affiliate)                             Filed herewith
                                                                                                     as Exhibit 23.8

      23.9     Consent of Brach, Neal, Daney & Spence, LLP (First American Records Management,       Filed herewith
               Inc.)                                                                                 as Exhibit 23.9

      23.10    Consent of Barbier Frinault & Associes (MAP, S.A.)                                    Filed herewith
                                                                                                       as Exhibit
                                                                                                          23.10




EXHIBIT NO.                                                                                              EXHIBIT
- -------------                                                                                        ---------------
                                                                                               
      24       Powers of Attorney                                                                     Contained on
                                                                                                       Pages II-8,
                                                                                                     II-10 and II-11
                                                                                                         of the
                                                                                                      Registration
                                                                                                        Statement

      25       Form T-1 Statement of Eligibility of The Bank of New York                             Filed herewith
                                                                                                      as Exhibit 25

      27       Financial Data Schedule--March 31, 1999                                                  (27)(19)

      99.1     Form of Letter of Transmittal                                                         Filed herewith
                                                                                                     as Exhibit 99.1

      99.2     Form of Notice of Guaranteed Delivery                                                 Filed herewith
                                                                                                     as Exhibit 99.2


- ------------------------

1.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 33-99950,
    filed with the Commission on December 1, 1995.

2.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-10359,
    filed with the Commission on August 16, 1996.

3.  Filed as an Exhibit to Iron Mountain's Annual Report on Form 10-K for the
    year ended December 31, 1996, filed with the Commission, File No. 0-27584.

4.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-24635,
    filed with the Commission on April 4, 1997, as amended on May 7, 1997 and
    May 13, 1997.

5.  Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated
    October 30, 1997, filed with the Commission, File No. 0-27584.

6.  Filed as an Exhibit to Iron Mountain's Quarterly Report on Form 10-Q for the
    quarter ended September 30, 1997, filed with the Commission, File No.
    0-27584.

7.  Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K/A dated
    November 10, 1997, filed with the Commission, File No. 0-27584.

8.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-41045,
    filed with the Commission on November 26, 1997.

9.  Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-44185,
    filed with the Commission on January 13, 1998.

10. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated
    March 9, 1998, filed with the Commission, File No. 0-27584.

11. Filed as an Exhibit to Iron Mountain's Annual Report on Form 10-K for the
    year ended December 31, 1997, filed with the Commission, File No. 0-27584.

12. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated July
    10, 1998, filed with the Commission, File No. 0-27584.

13. Filed as an Exhibit to Amendment No. 1 to Iron Mountain's Registration
    Statement No. 333-44187, filed with the Commission on August 3, 1998.

14. Filed as an Exhibit to Iron Mountain's Registration Statement No. 333-67765,
    filed with the Commission on November 23, 1998.

15. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated
    January 19, 1999, filed with the Commission, File No. 0-27584.

16. Filed as an Exhibit to Iron Mountain's Annual Report on Form 10-K for the
    year ended December 31, 1998, filed with the Commission, File No. 0-27584.

17. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated
    April 16, 1999, filed with the Commission, File No. 0-27584.

18. Filed as an Exhibit to Iron Mountain's Current Report on Form 8-K dated May
    11, 1999, filed with the Commission, File No. 0-27584.

19. Filed as an Exhibit to Iron Mountain's Quarterly Report on Form 10-Q for the
    quarter ended March 31, 1999, filed with the Commission, File No. 0-27584.

EX-5

                                                                      EXHIBIT 5


                                  SULLIVAN & WORCESTER LLP
                                   ONE POST OFFICE SQUARE
                                 BOSTON, MASSACHUSETTS 02109
                                       (617) 338-2800
                                    FAX NO. 617-338-2880


    IN WASHINGTON, D.C.                                     IN NEW YORK
1025 CONNECTICUT AVENUE, N.W.                             767 THIRD AVENUE
   WASHINGTON, D.C. 20038                              NEW YORK, NEW YORK 10017
      (202) 775-8190                                       (212) 486-8200
   FAX NO. 202-293-2275                                  FAX NO. 212-758-2151




                                                                    July 9, 1999




Iron Mountain Incorporated
745 Atlantic Avenue
Boston, Massachusetts  02111

Re:      Registration Statement on Form S-4
         $150,000,000 of Senior Subordinated Notes due 2011

Ladies and Gentlemen:

         The following opinion is furnished to you in connection with the
registration pursuant to a registration statement on Form S-4 (the
"Registration Statement") under the Securities Act of 1933, as amended (the
"Securities Act"), by Iron Mountain Incorporated, a Delaware corporation (the
"Company"), of $150,000,000 of Senior Subordinated Notes due 2011 (the
"Notes"), which Notes will initially be guaranteed (the "Guarantees") by each
of the Company's direct and indirect wholly owned restricted subsidiaries
(other than any excluded restricted subsidiary) (collectively, the
"Subsidiary Guarantors") and issued under an indenture, dated as of April 26,
1999, relating to the Notes (the "Indenture") by and among the Company, the
Subsidiary Guarantors and The Bank of New York, as Trustee (the "Trustee").

         We have acted as counsel to the Company in connection with the
preparation of the Registration Statement, and we have examined originals or
copies, certified or otherwise identified to our satisfaction, of corporate
records, certificates and statements of officers and accountants of the Company,
of public officials, and such other documents as we have considered necessary in
order to furnish the opinion hereinafter set forth. We express no opinion herein
as to the laws of any jurisdiction other than the laws of the State of New York.

         Based upon and subject to the foregoing, we are of the opinion that the
Company and the Subsidiary Guarantors have taken all necessary action to approve
the Indenture and the terms of the Notes and Guarantees, and when (i) the
Registration Statement has become effective under the Securities Act, (ii) the
Indenture has been duly executed and delivered by the Company, the Subsidiary
Guarantors and the Trustee, and the Notes have been duly executed by the Company
and authenticated by the Trustee, (iii) the Indenture has been qualified under
the Trust Indenture Act of 1939, as amended, and (iv) the Notes have been
delivered to the purchasers thereof against payment of the purchase price
therefore as described in the Registration Statement, the Notes and the
Guarantees will be legal, valid and binding obligations of the Company and the
Subsidiary Guarantors respectively, subject in each case to the effect of (a)
bankruptcy, insolvency, reorganization, moratorium or other similar laws
relating to or affecting the rights and remedies of creditors and the
obligations of debtors generally and (b) the application of general principles
of equity (regardless of whether enforcement is considered in proceedings at law
or in equity).

         We express no opinion as to the applicability (and, if applicable, the
effect) of Section 548 of the United States Bankruptcy Code or any comparable
provision of state law to the conclusions expressed above.





Iron Mountain Incorporated
July 9, 1999
Page 2

         We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to our firm made therein under the
caption "Legal Matters." In giving such consent, we do not thereby admit that we
come within the category of persons whose consent is required under Section 7 of
the Securities Act or the Rules and Regulations of the Securities and Exchange
Commission promulgated thereunder.

                                                   Very truly yours,

                                                   /s/ SULLIVAN & WORCESTER LLP
                                                   -----------------------------
                                                       SULLIVAN & WORCESTER LLP

EX-12

                                                                Exhibit 12




                           IRON MOUNTAIN INCORPORATED

       STATEMENT OF THE COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

                             (DOLLARS IN THOUSANDS)



                                                                                                                  PRO FORMA
                                                                                                          -------------------------
                                                                                         THREE MONTHS      FOR THE    FOR THE THREE
                                                YEAR ENDED DECEMBER 31,                 ENDED MARCH 31,   YEAR ENDED   MONTHS ENDED
                               -----------------------------------------------------  ------------------ DECEMBER 31,    MARCH 31,
                                 1994       1995       1996       1997       1998       1998      1999       1998          1999
                               ---------  ---------  ---------  ---------  ---------  ---------  ------- ------------  -----------
                                                                                              
Earnings:
  Income (loss) from continuing
    operations before provision
    (benefit) for Income taxes
    and minority interest      $   3,241  $   1,945  $   1,792   $ (4,601) $   3,391   $(1,583)  $   1,522  $   2,813    $   1,416
  Add: Fixed charges              13,472     17,058     21,939     37,489     61,169    14,191      16,232     73,860       18,215
                               ---------  ---------  ---------  ---------  ---------  ---------  ---------  ---------    ---------
                               $  16,713  $  19,003  $  23,731  $  32,888  $  64,560   $12,608   $  17,754  $  76,673    $  19,631
                               ---------  ---------  ---------  ---------  ---------  ---------  ---------  ---------    ---------
                               ---------  ---------  ---------  ---------  ---------  ---------  ---------  ---------    ---------
Fixed Charges:
  Interest expense             $   8,954  $  11,838  $  14,901  $  27,712  $  45,673   $10,721   $  11,944  $  54,944    $  13,384
  Interest portion of rent
    expense                        4,518      5,220      7,038      9,777     15,496     3,470       4,288     18,916        4,831
                               ---------  ---------  ---------  ---------  ---------  ---------  ---------  ---------    ---------
                               $  13,472  $  17,058  $  21,939  $  37,489  $  61,169   $14,191   $  16,232  $  73,860    $  18,215
                               ---------  ---------  ---------  ---------  ---------  ---------  ---------  ---------    ---------
                               ---------  ---------  ---------  ---------  ---------  ---------  ---------  ---------    ---------
Ratio of earnings to fixed
  charges                           1.2x       1.1x       1.1x      0.9x(1)     1.1x       0.9x(2)    1.1x       1.0x         1.1x


(1) For 1997, the Company would have needed to generate additional income from
    continuing operations before benefit for income taxes and minority interest
    of $4,601 to cover its fixed charges of $37,489.

(2) For the three months ended March 31, 1998, the Company would have needed
    to generate additional income from continuing operations before benefit
    for income taxes and minority interest of $1,583 to cover its
    fixed charges of $14,191.

EX-21

                                                                      EXHIBIT 21

                           Iron Mountain Incorporated

                                  SUBSIDIARIES




                                                                 Jurisdiction of
                    Subsidiary                                    Organization
- ----------------------------------------------------------        -------------

                                                               
Iron Mountain Records Management, Inc.                               Delaware
     Iron Mountain Records Management of Ohio, Inc.                  Delaware
     Iron Mountain Records Management of Michigan, Inc.              Delaware
           Iron Mountain Safe Deposit Corporation                    Michigan
     Iron Mountain/National Underground Storage, Inc.                Delaware
     Iron Mountain Records Management of San Antonio, Inc.           Delaware
     Iron Mountain Records Management of San Antonio-FP, Inc.        Delaware
     Iron Mountain Consulting Services, Inc.                         Delaware
     Iron Mountain of Maryland LLC                                   Delaware
     Carter Media Management, Inc.                                   Kentucky
     IM Billerica, Inc.                                              Massachusetts
     Criterion Atlantic Property, Inc.                               Delaware
     HIMSCORP of Philadelphia, Inc.                                  Delaware
     HIMSCORP of Pittsburgh, Inc.                                    Delaware
     HIMSCORP of New Orleans, Inc.                                   Delaware
     HIMSCORP of San Diego, Inc.                                     Delaware
     HIMSCORP of Los Angeles, Inc.                                   Delaware
     HIMSCORP of Cleveland, Inc.                                     Delaware
     HIMSCORP of Portland, Inc.                                      Delaware
     HIMSCORP of Detroit, Inc.                                       Delaware
     HIMSCORP of Houston, Inc.                                       Delaware
     Recordkeepers, Inc.                                             Delaware
     Arcus Data Security, Inc.                                       Delaware
           Arcus Data Security LLC                                   Delaware
           Datavault/United States Safe Deposit Company              California
           Iron Mountain Global, Inc.                                Delaware
                 Iron Mountain Global LLC                            Delaware
                 Iron Mountain (Netherlands) B.V                     Netherlands
                      Iron Mountain (UK) Ltd.                        United Kingdom
                          Britannia Data Management Limited          United Kingdom
Iron Mountain (Puerto Rico), Inc.                                    Puerto Rico
DSI Technology Escrow Services, Inc.                                 Delaware
Iron Mountain/Safesite, Inc.                                         Delaware
IM-AEI Acquisition Corp.                                             Delaware
     Iron Mountain Records Management of Utah, Inc.                  Delaware
Arcus Staffing Resources, Inc.                                       Delaware



- ------------------

Each entity is 100% owned by its parent, except that Britannia Data Management
Limited is owned 50.1% by Iron Mountain (UK) Ltd.

EX-23.1

                                                                    EXHIBIT 23.1



                  Consent of Independent Public Accountants


As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement on Form S-4 of our report dated July
2, 1999 for Iron Mountain Incorporated included in its Current Report on Form
8-K for the year ended December 31, 1998, filed with the Securities and
Exchange Commission on July 9, 1999, as well as our report dated February 19,
1999, on the supplemental schedule, Valuation and Qualifying Accounts,
included in its Form 10-K for the year ended December 31, 1998, filed with
the Securities and Exchange Commission on March 31, 1999 and to all
references to our Firm included in this registration statement.

                                              /s/ Arthur Andersen LLP


Boston, Massachusetts
July 9, 1999

EX-23.2

                                                                    EXHIBIT 23.2

                   Consent of Independent Public Accountants


As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement on Form S-4 of our report dated August
7, 1997 for Records Retention/FileSafe LP included in Iron Mountain
Incorporated's Form 8-K filed with the Securities and Exchange Commission on
November 25, 1997 and to all references to our Firm included in this
registration statement.



                                   /s/Abbott, Stringham & Lynch


Campbell, California
July 2, 1999

EX-23.3

                                                                  EXHIBIT 23.3


                    Consent of Independent Auditors


We consent to the reference to our firm under the caption "Experts" and the
incorporation by reference in the Registration Statement (Form S-4) of Iron
Mountain Incorporated of our report dated February 21, 1997, with respect to
the consolidated financial statements of HIMSCORP, Inc. and Subsidiaries as
of December 31, 1995 and 1996 and for the period from February 1, 1995
(commencement of operations) to December 31, 1995 and for the year ended
December 31, 1996 included in the Current Reports on Form 8-K dated October
30, 1997 and November 25, 1997 filed by Iron Mountain Incorporated with the
Securities and Exchange Commission.


                                         /s/ Ernst & Young LLP


Chicago, Illinois
July 2, 1999

EX-23.4

                                                                    EXHIBIT 23.4

                       Consent of Independent Auditors


We consent to the reference to our firm under the caption "Experts" in the
registration statement on Form S-4 of Iron Mountain Incorporated filed on or
about July 9, 1999 and to the incorporation by reference therein of our
reports (a) dated February 23, 1998, with respect to the consolidated
financial statements of Arcus Technology Services, Inc. for each of the two
years in the period ended December 31, 1997 and the five-month period ended
December 31, 1995 and the  consolidated financial statements of Arcus, Inc.
(Predecessor Company) for the seven-month period ended July 31, 1995,
included in its Current Report on Form 8-K dated March 9, 1998 filed with the
Securities and Exchange Commission, and (b) dated April 30, 1997 (except Note
15, as to which the date is September 26, 1997), with respect to the
consolidated financial statements of Arcus Group, Inc. for each of the two
years in the period ended December 31, 1996, included in its Current Reports
on Form 8-K dated October 30, 1997 and November 25, 1997, both filed with the
Securities and Exchange Commission.



                                   /s/ Ernst & Young LLP



Dallas, Texas
July 2, 1999

EX-23.5

                                                                    EXHIBIT 23.5


                   Consent of Independent Public Accountants


As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement on Form S-4 of our reports dated
March 13,1998, February 25, 1998 and August 21, 1998 for Sloan Vaults, Inc.
and Affiliate, Midwest Records Management and InterMation, Inc.,
respectively, included in Iron Mountain Incorporated's Form 8-K filed with
the Securities and Exchange Commission on September 18, 1998, and to all
references to our Firm included in this registration statement.



                                                  /s/ Arthur Andersen LLP


San Diego,California
Omaha, Nebraska
Seattle, Washington
July 2, 1999

EX-23.6

                                                                  EXHIBIT 23.6

                     Consent of Independent Public Accountants

As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement on Form S-4 of our report dated July
30, 1998 for National Underground Storage, Inc. included in Iron Mountain
Incorporated's Form 8-K/A filed with the Securities and Exchange Commission
on August 7, 1998 and to all references to our Firm included in this
registration statement.


                                  /s/ Carbis Walker & Associates, LLP

Butler, Pennsylvania
July 2, 1999

EX-23.7

                                                                EXHIBIT 23.7

                        Consent of Independent Public Accountants

As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement on Form S-4 of our report dated
February 9, 1999 for Britannia Data Management Limited included in Iron
Mountain Incorporated's Form 8-K/A filed with the Securities and Exchange
Commission on March 22, 1999 and to all references to our Firm included in
this registration statement.


                                       /s/  Robson Rhodes
                                            Chartered Accountants

Birmingham, England
July 2, 1999

EX-23.8

                                                                 EXHIBIT 23.8

                     Consent of Independent Public Accountants

As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement on Form S-4 of our report dated
April 8, 1999 on the financial statements of Data Base, Inc. and Affiliate
for the periods ended December 31, 1996, 1997 and 1998 included in Iron
Mountain Incorporated's Form 8-K filed with the Securities and Exchange
Commission on April 16, 1999 and to the reference to us under the heading
"Experts" in this registration statement.


                                          /s/ Moss Adams LLP

Seattle, Washington
July 2, 1999

EX-23.9

                                                                EXHIBIT 23.9

                  Consent of Independent Public Accountants

As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement on Form S-4 of our report dated
April 1, 1999 for First American Records Management, Inc. included in Iron
Mountain Incorporated's Form 8-K filed with the Securities and Exchange
Commission on July 9, 1999, and to all references to our Firm included in
this registration statement.

                             /s/ Brach, Neal, Daney & Spence, LLP


San Jose, California
July 9, 1999

EX-23.10

                                                                   EXHIBIT 23.10


                  Consent of Independent Public Accountants


As independent public accounts, we hereby consent to the incorporation by
reference in this registration statement on Form S-4 of our report dated May
7, 1999 for MAP, S.A. included in Iron Mountain Incorporated's Form 8-K filed
with the Securities and Exchange Commission on July 9, 1999 and to all
references to our Firm included in this registration statement.



                                          /s/ Barbier Frinault & Associes
                                              ARTHUR ANDERSEN



Paris, France
July 9, 1999

EX-25

                                                                      Exhibit 25


- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------


                                    FORM T-1

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                            STATEMENT OF ELIGIBILITY
                   UNDER THE TRUST INDENTURE ACT OF 1939 OF A
                    CORPORATION DESIGNATED TO ACT AS TRUSTEE

                      CHECK IF AN APPLICATION TO DETERMINE
                      ELIGIBILITY OF A TRUSTEE PURSUANT TO
                             SECTION 305(b)(2) |__|



                              THE BANK OF NEW YORK
               (Exact name of trustee as specified in its charter)


New York                                               13-5160382
(State of incorporation                                (I.R.S. employer
if not a U.S. national bank)                           identification no.)

One Wall Street, New York, N.Y.                        10286
(Address of principal executive offices)               (Zip code)





                           IRON MOUNTAIN INCORPORATED
               (Exact name of obligor as specified in its charter)


Delaware                                               04-3107342
(State or other jurisdiction of                        (I.R.S. employer
incorporation or organization)                         identification no.)


                             TABLE OF CO-REGISTRANTS
                                                                            
Arcus Data Security, Inc.                            Delaware                     94-2148675
Arcus Data Security LLC                              Delaware                     04-3462538
Arcus Staffing Resources, Inc.                       Delaware                     94-3229868
Carter Media Management, Inc.                        Kentucky                     61-1311186
Criterion Atlantic Property, Inc.                    Delaware                     04-3102768
Datavault/United States Safe Deposit Company         California                   95-3769759
DSI Technology Escrow Services, Inc.                 Delaware                     77-0154485
HIMSCORP of Cleveland, Inc.                          Delaware                     36-4072100
HIMSCORP of Detroit, Inc.                            Delaware                     36-3994880
HIMSCORP of Houston, Inc.                            Delaware                     36-4072098
HIMSCORP of Los Angeles, Inc.                        Delaware                     36-4027036
HIMSCORP of New Orleans, Inc.                        Delaware                     36-3994882
HIMSCORP of Philadelphia, Inc.                       Delaware                     36-3998771








                                                                            
HIMSCORP of Pittsburgh, Inc.                         Delaware                     36-3994877
HIMSCORP of Portland, Inc.                           Delaware                     91-1826931
HIMSCORP of San Diego, Inc.                          Delaware                     36-4024320
IM-AEI Acquisition Corp.                             Delaware                     33-0486463
IM Billerica, Inc.                                   Massachusetts                04-3373720
Iron Mountain Consulting Services, Inc.              Delaware                     04-3241466
Iron Mountain of Maryland LLC                        Delaware                     52-2140928
Iron Mountain/National Underground Storage, Inc.     Delaware                     25-1016055
Iron Mountain Records Management, Inc.               Delaware                     04-3038590
Iron Mountain Records Management of Michigan,        Delaware                     04-3346223
Inc.
Iron Mountain Records Management of Ohio, Inc.       Delaware                     31-1419399
Iron Mountain Records Management of San              Delaware                     04-3376180
Antonio, Inc.
Iron Mountain Records Management of San              Delaware                     04-3377554
Antonio-FP, Inc.
Iron Mountain Records Management of Utah, Inc.       Delaware                     04-3402733
Iron Mountain Safe Deposit Corporation               Michigan                     04-3402751
Iron Mountain/Safesite, Inc.                         Delaware                     04-3071673
Recordkeepers, Inc.                                  Delaware                     52-1578272







745 Atlantic Avenue
Boston, MA                                             02111
(Address of principal executive offices)               (Zip code)

                             ----------------------

                    8 1/4% Senior Subordinated Notes Due 2011
                       (Title of the indenture securities)


- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

                                       2




1.      GENERAL INFORMATION. FURNISH THE FOLLOWING INFORMATION AS TO THE
        TRUSTEE:

        (a) NAME AND ADDRESS OF EACH EXAMINING OR SUPERVISING AUTHORITY TO WHICH
IT IS SUBJECT.




- --------------------------------------------------------------------------------
                  Name                                        Address
- --------------------------------------------------------------------------------
                                                      
        Superintendent of Banks of the State of          2 Rector Street, New York,
        New York                                         N.Y.  10006, and Albany, N.Y. 12203

        Federal Reserve Bank of New York                 33 Liberty Plaza, New York,
                                                         N.Y.  10045

        Federal Deposit Insurance Corporation            Washington, D.C.  20429

        New York Clearing House Association              New York, New York   10005




        (b) WHETHER IT IS AUTHORIZED TO EXERCISE CORPORATE TRUST POWERS.

        Yes.

2.      AFFILIATIONS WITH OBLIGOR.

        IF THE OBLIGOR IS AN AFFILIATE OF THE TRUSTEE, DESCRIBE EACH SUCH
        AFFILIATION.

        None.

16.     LIST OF EXHIBITS.

        EXHIBITS IDENTIFIED IN PARENTHESES BELOW, ON FILE WITH THE COMMISSION,
        ARE INCORPORATED HEREIN BY REFERENCE AS AN EXHIBIT HERETO, PURSUANT TO
        RULE 7A-29 UNDER THE TRUST INDENTURE ACT OF 1939 (THE "ACT") AND 17
        C.F.R. 229.10(d).

        1.     A copy of the Organization Certificate of The Bank of New York
               (formerly Irving Trust Company) as now in effect, which contains
               the authority to commence business and a grant of powers to
               exercise corporate trust powers. (Exhibit 1 to Amendment No. 1 to
               Form T-1 filed with Registration Statement No. 33-6215, Exhibits
               1a and 1b to Form T-1 filed with Registration Statement No.
               33-21672 and Exhibit 1 to Form T-1 filed with Registration
               Statement No. 33-29637.)

        4.     A copy of the existing By-laws of the Trustee. (Exhibit 4 to Form
               T-1 filed with Registration Statement No. 33-31019.)

        6.     The consent of the Trustee required by Section 321(b) of the
               Act. (Exhibit 6 to Form T-1 filed with Registration Statement
               No. 33-44051.)

        7.     A copy of the latest report of condition of the Trustee published
               pursuant to law or to the requirements of its supervising or
               examining authority.





                                    SIGNATURE



        Pursuant to the requirements of the Act, the Trustee, The Bank of New
York, a corporation organized and existing under the laws of the State of New
York, has duly caused this statement of eligibility to be signed on its behalf
by the undersigned, thereunto duly authorized, all in The City of New York, and
State of New York, on the 6th day of July, 1999.


                                               THE BANK OF NEW YORK



                                               By:  /s/ Iliana A. Arciprete
                                                  ---------------------------
                                                   Name:  Iliana A. Arciprete
                                                   Title: Assistant Treasurer

                                       4





                                                                       Exhibit 7

                       Consolidated Report of Condition of

                              THE BANK OF NEW YORK

                    of One Wall Street, New York, N.Y. 10286
                     And Foreign and Domestic Subsidiaries,
a member of the Federal Reserve System, at the close of business March 31, 1999,
published in accordance with a call made by the Federal Reserve Bank of this
District pursuant to the provisions of the Federal Reserve Act.




                                                                             DOLLAR AMOUNTS
ASSETS                                                                         IN THOUSANDS
                                                                              
Cash and balances due from depository institutions:
   Noninterest-bearing balances and currency and coin..                          $4,508,742
   Interest-bearing balances...........................                           4,425,071
Securities:
   Held-to-maturity securities.........................                             836,304
   Available-for-sale securities.......................                           4,047,851
Federal funds sold and Securities purchased under
   agreements to resell................................                           1,743,269
Loans and lease financing receivables:
   Loans and leases, net of unearned
     income............................................                           39,349,679
   LESS: Allowance for loan and
     lease losses......................................                             603,025
   LESS: Allocated transfer risk
     reserve...........................................                              15,906
   Loans and leases, net of unearned income,
     allowance, and reserve............................                          38,730,748
Trading Assets.........................................                           1,571,372
Premises and fixed assets (including capitalized
   leases).............................................                             685,674
Other real estate owned................................                              10,331
Investments in unconsolidated subsidiaries and
   associated companies................................                             182,449
Customers' liability to this bank on acceptances
   outstanding.........................................                           1,184,822
Intangible assets......................................                           1,129,636
Other assets...........................................                           2,632,309
                                                                                -----------
Total assets...........................................                         $61,688,578
                                                                                -----------
                                                                                -----------








                                                                             
LIABILITIES
Deposits:
   In domestic offices.................................                         $25,731,036
   Noninterest-bearing.................................                          10,252,589
   Interest-bearing....................................                          15,478,447
   In foreign offices, Edge and Agreement
     subsidiaries, and IBFs............................                          18,756,302
   Noninterest-bearing.................................                             111,386
   Interest-bearing....................................                          18,644,916
Federal funds purchased and Securities sold under
   agreements to repurchase............................                           3,276,362
Demand notes issued to the U.S.Treasury................                             230,671
Trading liabilities....................................                           1,554,493
Other borrowed money:
   With remaining maturity of one year or less.........                           1,154,502
   With remaining maturity of more than one year
     through three years...............................                                 465
   With remaining maturity of more than three years....                              31,080
Bank's liability on acceptances executed and
   outstanding.........................................                           1,185,364
Subordinated notes and debentures......................                           1,308,000
Other liabilities......................................                           2,743,590
                                                                                -----------
Total liabilities......................................                          55,971,865
                                                                                -----------
                                                                                -----------
EQUITY CAPITAL
Common stock...........................................                           1,135,284
Surplus................................................                             764,443
Undivided profits and capital reserves.................                           3,807,697
Net unrealized holding gains (losses) on
   available-for-sale securities.......................                              44,106
Cumulative foreign currency translation adjustments....                         (    34,817)
                                                                                -----------
Total equity capital...................................                           5,716,713
                                                                                -----------
Total liabilities and equity capital...................                         $61,688,578
                                                                                -----------
                                                                                -----------









         I, Thomas J. Mastro, Senior Vice President and Comptroller of the
above-named bank do hereby declare that this Report of Condition has been
prepared in conformance with the instructions issued by the Board of Governors
of the Federal Reserve System and is true to the best of my knowledge and
belief.


                                                    Thomas J. Mastro

         We, the undersigned directors, attest to the correctness of this Report
of Condition and declare that it has been examined by us and to the best of our
knowledge and belief has been prepared in conformance with the instructions
issued by the Board of Governors of the Federal Reserve System and is true and
correct.

Thomas A. Renyi
Alan R. Griffith                                                  Directors
Gerald L. Hassell


- --------------------------------------------------------------------------------

EX-99.1

                                                                   EXHIBIT 99.1

                                  IRON MOUNTAIN INCORPORATED

                                 FORM OF LETTER OF TRANSMITTAL

                            8 1/4% SENIOR SUBORDINATED NOTES DUE 2011

               THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME,
                ON             , 1999 UNLESS EXTENDED (THE "EXPIRATION DATE").

                                    THE EXCHANGE AGENT IS:

                                     THE BANK OF NEW YORK



                                                                                 
    BY REGISTERED OR CERTIFIED MAIL:                                                BY HAND OR OVERNIGHT DELIVERY:

          THE BANK OF NEW YORK                                                           THE BANK OF NEW YORK
        101 BARCLAY STREET - 7E                                                           101 BARCLAY STREET
        NEW YORK, NEW YORK 10286                                                   CORPORATE TRUST SERVICES WINDOW
       ATTENTION: NORIKO MIYAZAKI                                                            GROUND LEVEL
         REORGANIZATION SECTION                                                        NEW YORK, NEW YORK 10286
                                                                                      ATTENTION: NORIKO MIYAZAKI
                                                                                        REORGANIZATION SECTION


                                       BY FACSIMILE FOR ELIGIBLE INSTITUTIONS:
                                                   (212) 815-4699
                                      FOR CONFIRMATION AND/OR INFORMATION CALL:
                                                   (212) 815-6333

         Delivery of this instrument to an address other than as set forth above
or transmission of instructions via a facsimile number other than the one listed
above will not constitute a valid delivery. The instructions accompanying this
letter of transmittal should be read carefully before this letter of transmittal
is completed.

         The undersigned acknowledges that he or she has received the
Prospectus dated       , 1999 (the "Prospectus") of Iron Mountain Incorporated
(the "Company") and this Letter of Transmittal (the "Letter of Transmittal"),
which together constitute the company's offer (the "Exchange Offer") to
exchange $1,000 principal amount (or integral multiples in excess thereof) of
its 8 1/4% Senior Subordinated Notes due 2011 (the "New Notes"), which have
been registered under the Securities Act of 1933, as amended (the "Securities
Act"), pursuant to a Registration Statement of which the Prospectus is a
part, for each $1,000 principal amount (or integral multiples in excess
thereof) of its outstanding 8 1/4% Senior Subordinated Notes due 2011 (the
"Old Notes"), of which $150,000,000 aggregate principal amount is
outstanding. Other capitalized terms used but not defined herein have the
meaning given to them in the Prospectus.

         The Letter of Transmittal is to be used by holders of Old Notes (i) if
the Old Notes are to be physically delivered herewith; (ii) if delivery of the
Old Notes is made by book-entry transfer to the Exchange Agent's account at the
Depositary Trust Company ("DTC") pursuant to the procedures set forth in the
Prospectus under "The Exchange Offer--Procedures for Tendering" by any financial
institution that is a participant in dtc and whose name appears on a security
position listing as the owner of the Old Notes or (iii) if the guaranteed
delivery procedures described in the Prospectus are to be utilized. DELIVERY OF
DOCUMENTS TO DTC DOES NOT CONSTITUTE DELIVERY TO THE EXCHANGE AGENT.

         The term "Holder" with respect to the Exchange Offer means any person
(i) in whose name Old Notes are registered on the books of the Company or any
other person who has obtained a properly completed bond power from the
registered holder or (ii) in whose name the Old Notes are held of record by DTC
who desires to deliver such Old Notes by book-entry transfer at DTC. The
undersigned has completed, executed and delivered this Letter of Transmittal to
indicate the action the undersigned desires to take with respect to the Exchange
Offer. Holders who wish to tender their Old Notes must complete this letter in
its entirety.

         Holders who desire to tender their Old Notes and whose Old Notes are
not lost but are not immediately available or who cannot deliver their Old Notes
and all other documents required hereby to the Exchange Agent by the Expiration
Date or who are unable to complete the procedure for book-entry transfer on a
timely basis must tender their Old Notes pursuant to the guaranteed delivery
procedure set forth in "The Exchange Offer--Procedures for Tendering."







            PLEASE READ THE INSTRUCTIONS ACCOMPANYING THIS LETTER OF TRANSMITTAL
                          CAREFULLY BEFORE CHECKING ANY BOX BELOW.

            DESCRIPTION OF 8 1/4% SENIOR SUBORDINATED NOTES DUE 2011 (OLD NOTES)



- ------------------------------------------------------------------------------------------------------------------------
                                                                                                PRINCIPAL AMOUNT
         NAME(S) AND                                                                          TENDERED (MUST BE IN
        ADDRESS(ES) OF                                         AGGREGATE PRINCIPAL              DENOMINATIONS OF
     REGISTERED HOLDER(S)              CERTIFICATE              AMOUNT REPRESENTED      $1,000 OR ANY INTEGRAL MULTIPLES
  (PLEASE FILL IN, IF BLANK)            NUMBER(S)*              BY CERTIFICATE(S)             IN EXCESS THEREOF )**
- ------------------------------------------------------------------------------------------------------------------------
                                                                               

- ------------------------------------------------------------------------------------------------------------------------

- ------------------------------------------------------------------------------------------------------------------------

- ------------------------------------------------------------------------------------------------------------------------
                                          TOTAL
- ------------------------------------------------------------------------------------------------------------------------
*        NEED NOT BE COMPLETED BY HOLDERS OF OLD NOTES WHO TENDER BY BOOK-ENTRY TRANSFER.
**       NEED NOT BE COMPLETED BY HOLDERS WHO WISH TO TENDER WITH RESPECT TO ALL OLD NOTES LISTED.
- ------------------------------------------------------------------------------------------------------------------------


NOTE:  SIGNATURES MUST BE PROVIDED BELOW.  PLEASE READ THE ACCOMPANYING
INSTRUCTIONS CAREFULLY.

/ /      CHECK HERE IF TENDERED OLD NOTES ARE BEING DELIVERED BY BOOK-ENTRY

         TRANSFER MADE TO THE ACCOUNT MAINTAINED BY THE EXCHANGE AGENT WITH DTC
         AND COMPLETE THE FOLLOWING:

Name of Tendering Institution:_______________________________________________
DTC Book-Entry Account Number:________________ Transaction Code No:_________

/ /    CHECK HERE IF TENDERED OLD NOTES ARE BEING DELIVERED PURSUANT TO A NOTICE
       OF GUARANTEED DELIVERY PREVIOUSLY SENT TO THE EXCHANGE AGENT AND
       COMPLETE THE FOLLOWING:

Name(s) of Registered Holder(s):_______________________________________________
Date of Execution of Notice of Guaranteed Delivery:____________________________
Name of Institution which Guaranteed Delivery :________________________________
DTC Account Number:____________________________________________________________
If Delivered by Book-Entry Transfer:
  Name of Tendering Institution:________________________________________________
  DTC Book-Entry Account No.:___________________  Transaction Code No.:_________

/ /      CHECK HERE IF YOU ARE A BROKER-DEALER TENDERING OLD NOTES ACQUIRED AS
         A RESULT OF MARKET-MAKING OR OTHER TRADING ACTIVITIES AND WISH TO
         RECEIVE 10 ADDITIONAL COPIES OF THE PROSPECTUS AND 10 COPIES OF ANY
         AMENDMENTS OR SUPPLEMENTS THERETO.

         Name:_________________________________________________________________
         Address:______________________________________________________________


             PLEASE READ THE ACCOMPANYING INSTRUCTIONS CAREFULLY.






TO: THE BANK OF NEW YORK

Ladies and Gentlemen:

         Subject to the terms and conditions of the Exchange Offer, the
undersigned hereby tenders to the Company the principal amount of Old Notes
indicated above. Subject to and effective upon the acceptance for exchange of
the principal amount of Old Notes tendered in accordance with this Letter of
Transmittal, the undersigned sells, assigns and transfers to, or upon the order
of, the Company all right, title and interest in and to the Old Notes tendered
hereby. The undersigned hereby irrevocably constitutes and appoints the Exchange
Agent its agent and attorney-in-fact (with full knowledge that the Exchange
Agent also acts as the agent of the Company) with respect to the tendered Old
Notes with full power of substitution to (i) deliver such Old Notes to the
Company or transfer ownership of such Old Notes on the account books maintained
by DTC, in each case, together with all accompanying evidences of transfer and
authenticity to, or upon the order of, the Company, (ii) present such Old Notes
or transfer ownership of such Old Notes on the account books maintained by DTC,
for transfer on the books of the Company and (iii) receive all benefits and
otherwise exercise all rights of beneficial ownership of such Old Notes, all in
accordance with the terms of the Exchange Offer. The power of attorney granted
in this paragraph shall be deemed irrevocable and coupled with an interest.

         The undersigned hereby represents and warrants that he or she has
full power and authority to tender, sell, assign and transfer the Old Notes
tendered hereby and that the Company will acquire good and unencumbered title
thereto, free and clear of all liens, restrictions, charges and encumbrances
and not subject to any adverse claim, when the same are acquired by the
Company. The undersigned hereby acknowledges that this Exchange Offer is
being made in reliance upon an interpretation by the staff of the Securities
and Exchange Commission that any New Notes acquired in exchange for Old Notes
tendered hereby may be offered for sale, resold and otherwise transferred by
holders thereof (other than any such holder that is an "affiliate" of the
Company or any of its subsidiaries within the meaning of Rule 405 under the
Securities Act of 1933 (the "Securities Act") or any holder that is a
broker-dealer who acquired Old Notes directly from the Company to resell
pursuant to Rule 144A or any other exemption under the Securities Act),
without compliance with the registration and prospectus delivery provisions
of the Securities Act, provided that such New Notes are acquired in the
ordinary course of business of the holder receiving such New Notes and that
neither the holder nor any such other person has an arrangement with any
person to participate in the distribution of such New Notes. The undersigned
hereby further represents that (i) the New Notes acquired pursuant to the
Exchange Offer are being obtained in the ordinary course of such holder's
business, (ii) such holder has no arrangements with any person to participate
in the distribution (within the meaning of the Securities Act) of such New
Notes and (iii) such holder is not an "affiliate", as defined under Rule 405
of the Securities Act of the Company or any of its subsidiaries or, if such
holder is an affiliate, that such holder will comply with the registration
and prospectus delivery requirements of the Securities Act to the extent
applicable. If the undersigned is not a broker-dealer, the undersigned
represents that it is not engaged in, and does not intend to engage in, a
distribution of New Notes. If the undersigned is a broker-dealer that
acquired Old Notes for its own account as a result of market-making
activities or other trading activities, and who receives New Notes in
exchange for those Old Notes, it acknowledges that it will deliver a
prospectus in connection with any resale of such New Notes; however, by so
acknowledging and by delivering a prospectus, the undersigned will not be
deemed to admit that it is an "underwriter" within the meaning of the
Securities Act. The undersigned will, upon request, execute and deliver any
additional documents deemed by the Exchange Agent or the Company to be
necessary or desirable to complete the assignment, transfer and purchase of
the Old Notes tendered hereby.

         For purposes of the Exchange Offer, the Company shall be deemed to have
accepted validly tendered Old Notes, when, as and if the Company has given oral
or written notice of acceptance thereof to the Exchange Agent.

         If any tendered Old Notes are not accepted for exchange pursuant to the
Exchange Offer for any reason, any such unaccepted Old Notes will be returned
(except as noted below with respect to tenders through DTC), without expense, to
the undersigned at the address shown below or at a different address as may be
indicated herein under "Special Payment Instructions" as promptly as practicable
after the Expiration Date.

         All authority herein conferred or agreed to be conferred in this Letter
of Transmittal shall survive the death, incapacity or dissolution of the
undersigned, and any obligation of the undersigned hereunder shall be binding
upon the administrators, legal representatives, heirs, personal representatives,
successors and assigns of the undersigned.

         The undersigned understands that tenders of Old Notes pursuant to the
procedures described under the caption "The Exchange Offer--Procedures for
Tendering" in the Prospectus and in the instructions hereto will constitute a
binding agreement between the undersigned and the Company upon the terms and
subject to the conditions of the Exchange Offer.







         Unless otherwise indicated under "Special Payment Instructions," please
issue the New Notes issued in exchange for the Old Notes accepted for exchange
and return any Old Notes not tendered or not exchanged in the name(s) of the
undersigned (or, in either such event, in the case of Old Notes tendered by DTC,
by credit to the account at DTC). Similarly, unless otherwise indicated under
"Special Delivery Instructions," please send the New Notes issued in exchange
for the Old Notes accepted for exchange and any Old Notes not tendered or not
exchanged (and accompanying documents, as appropriate) to the undersigned at the
address shown below the undersigned's signature(s), unless, in either event,
tender is being made through DTC. In the event that both "Special Payment
Instructions" and "Special Delivery Instructions" are completed, please issue
the New Notes issued in exchange for the Old Notes accepted for exchange and
return any Old Notes not tendered or not exchanged in the name(s) of, and send
said New Notes to, the person(s) so indicated. The undersigned recognizes that
the Company has no obligation pursuant to the "Special Payment Instructions" and
"Special Delivery Instructions" to transfer any Old Notes from the name of the
registered holder(s) thereof if the Company does not accept for exchange any of
the Old Notes so tendered.

         Holders of the Old Notes who wish to tender their Old Notes and (i)
whose Old Notes are not immediately available or (ii) who cannot deliver their
Old Notes, this Letter of Transmittal or any other documents required hereby to
the Exchange Agent prior to the Expiration Date, may tender their Old Notes
according to the guaranteed delivery procedures set forth in the Prospectus
under the caption "The Exchange Offer--Guaranteed Delivery Procedures." See
Instruction 1 regarding the completion of the Letter of Transmittal printed
below.


                         SPECIAL PAYMENT INSTRUCTIONS
                        (SEE INSTRUCTIONS 3, 4  AND 5)

To be completed ONLY if certificates for Old Notes in a principal amount not
tendered or not purchased, or New Notes issued in exchange for Old Notes
accepted for exchange, are to be issued in the name of someone other than the
undersigned.

Issue New Notes to:


Name:___________________________________________________________________________
                                (Please Print)
Address:________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________
                              (Include Zip Code)

________________________________________________________________________________
                  (Tax Identification or Social Security No.)


                         SPECIAL DELIVERY INSTRUCTIONS
                        (SEE INSTRUCTIONS 3, 4  AND 5)

To be completed ONLY if certificates for Old Notes in a principal amount not
tendered or not purchased, or New Notes issued in exchange for Old Notes
accepted for exchange are to be sent to someone other than the undersigned, or
the undersigned at an address other than that shown above.

Mail to:

Name:___________________________________________________________________________
                                  (Please Print)
Address:________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________
                              (Include Zip Code)
________________________________________________________________________________
                   (Tax Identification or Social Security No.)


IMPORTANT: THIS LETTER OR A FACSIMILE HEREOF (TOGETHER WITH THE CERTIFICATES FOR
OLD NOTES OR A BOOK-ENTRY CONFIRMATION AND ALL OTHER REQUIRED DOCUMENTS OR THE
NOTICE OF GUARANTEED DELIVERY) MUST BE RECEIVED BY THE EXCHANGE AGENT PRIOR TO
5:00 P.M., NEW YORK CITY TIME, ON THE EXPIRATION DATE.

- --------------------------------------------------------------------------------

          PLEASE READ THIS ENTIRE LETTER OF TRANSMITTAL CAREFULLY BEFORE
                              COMPLETING ANY BOX ABOVE.






                               PLEASE SIGN HERE
WHETHER OR NOT OLD NOTES ARE BEING PHYSICALLY TENDERED HEREBY

____________________________________________________________ Date: _____________

____________________________________________________________ Date: _____________
Signature(s) of Registered holder(s) or Authorized Signatory

Area Code and Telephone Number: ________________________________________________

         The above lines must be signed by the registered holder(s) of Old Notes
as their name(s) appear(s) on the Old Notes or, if tendered by a participant in
DTC, exactly as such participant's name appears on a security position listing
as the owner of the Old Notes or by person(s) authorized to become registered
holder(s) by properly executed bond power and other documents transmitted with
this Letter of Transmittal. If Old Notes to which this Letter of Transmittal
relates are held of record by two or more joint holders, then all such holders
must sign this Letter of Transmittal. If signature is by a trustee, executor,
administrator, guardian, attorney-in-fact, officer of a corporation or other
person acting in a fiduciary or representative capacity, such person must (i)
set forth his or her full title below and (ii) unless waived by the Company,
submit evidence satisfactory to the Company of such person's authority so to
act. See Instruction 3 regarding the completion of this Letter of Transmittal
printed below.

         If the signature appearing above is not the registered holder(s) of the
Old Notes, then the registered holder must sign a valid proxy.

Name(s):________________________________________________________________________

________________________________________________________________________________
                               (Please Print)

Capacity (full title):__________________________________________________________

Address:________________________________________________________________________

________________________________________________________________________________
                             (Include Zip Code)

                          GUARANTEE OF SIGNATURE(S)
                      (IF REQUIRED - SEE INSTRUCTION 3)

Authorized Signature:___________________________________________________________

Name:___________________________________________________________________________
                                 (Please Print)

Name of Firm:___________________________________________________________________

Address:________________________________________________________________________

________________________________________________________________________________
                             (Include Zip Code)

Title:__________________________________________________________________________

Area Code and Telephone No.:____________________________________________________

Dated:__________________________________________________________________________

________________________________________________________________________________







                                INSTRUCTIONS

                   FORMING PART OF THE TERMS AND CONDITIONS
                            OF THE EXCHANGE OFFER

         1. DELIVERY OF THIS LETTER OF TRANSMITTAL AND OLD NOTES. The tendered
Old Notes (or a confirmation of a book-entry transfer into the Exchange Agent's
account at DTC of all Old Notes delivered electronically), as well as a properly
completed and duly executed copy of this Letter of Transmittal or facsimile
hereof and any other documents required by this Letter of Transmittal, must be
received by the Exchange Agent at its address set forth herein prior to 5:00
p.m., New York City time, on the Expiration Date. The method of delivery of the
tendered Old Notes, this Letter of Transmittal and all other required documents
to the Exchange Agent is at the election and risk of the holder and, except as
otherwise provided below, the delivery will be deemed made only when actually
received by the Exchange Agent. Instead of delivery by mail, it is recommended
that the holder use an overnight or hand delivery service. In all cases,
sufficient time should be allowed to assure timely delivery. No Letter of
Transmittal or Old Notes should be sent to the Company.

         Holders who wish to tender their Old Notes and (i) whose Old Notes are
not immediately available, or (ii) who cannot deliver their Old Notes, this
Letter of Transmittal or any other documents required hereby to the Exchange
Agent prior to 5:00 p.m., New York City time, on the Expiration Date, must
tender their Old Notes according to the guaranteed delivery procedures set forth
in the Prospectus. Pursuant to such procedures: (i) such tender must be made by
or through a member firm of a registered national securities exchange or of the
National Association of Securities Dealers, Inc., or a commercial bank or trust
company having an office or correspondent in the United States or an "eligible
guarantor institution" (an "Eligible Institution") within the meaning of Rule
17Ad-15 under the Securities Exchange Act of 1934, as amended; (ii) prior to
the Expiration Date, the Exchange Agent must have received from the Eligible
Institution a properly completed and duly executed Notice of Guaranteed Delivery
(by facsimile transmission, mail or hand delivery) setting forth the name and
address of the holder of the Old Notes, the certificate number or numbers of
such Old Notes and the principal amount of Old Notes tendered, stating that the
tender is being made thereby and guaranteeing that, within three business days
after the Expiration Date, this Letter of Transmittal (or facsimile hereof)
together with the Old Notes (or a confirmation of electronic delivery of
book-entry delivery into the Exchange Agent's account at DTC) and any other
required documents will be deposited by the Eligible Institution with the
Exchange Agent; and (iii) such properly completed and executed Letter of
Transmittal (or facsimile hereof), as well as all other documents required by
this Letter of Transmittal and all tendered Old Notes in proper form for
transfer (or a confirmation of electronic delivery of book-entry delivery into
the Exchange Agent's account at DTC), must be received by the Exchange Agent
within three business days after the Expiration Date, all as provided in the
Prospectus under the caption "The Exchange Offer -- Guaranteed Delivery
Procedures." Any holder of Old Notes who wishes to tender his or her Old Notes
pursuant to the guaranteed delivery procedures described above must ensure that
the Exchange Agent receives the Notice of Guaranteed Delivery prior to 5:00
p.m., New York City time, on the Expiration Date. Upon request of the Exchange
Agent, a Notice of Guaranteed Delivery will be sent to holders who wish to
tender their Old Notes according to the guaranteed delivery procedures set forth
above.

         All questions as to the validity, form, eligibility (including time of
receipt) and acceptance of tendered Old Notes and withdrawal of tendered Old
Notes will be determined by the Company in its sole discretion, which
determination will be final and binding. The Company reserves the absolute right
to reject any and all Old Notes not properly tendered or any Old Notes the
Company's acceptance of which would, in the opinion of counsel for the Company,
be unlawful. The Company also reserves the right to waive any defects or
irregularities or conditions of tender as to the Exchange Offer and/or
particular Old Notes. The Company's interpretation of the terms and conditions
of the Exchange Offer (including the instructions in this Letter of Transmittal)
shall be final and binding on all parties. Unless waived, any defects or
irregularities in connection with tenders of Old Notes must be cured within such
time as the Company shall determine. Neither the Company, the Exchange Agent nor
any other person shall be under any duty to give notification of defects or
irregularities with respect to tenders of Old Notes, nor shall any of them incur
any liability for failure to give such notification. Tenders of Old Notes will
not be deemed to have been made until such defects or irregularities have been
cured or waived. Any Old Notes received by the Exchange Agent that are not
validly tendered and as to which the defects or irregularities have not been
cured or waived will be returned by the Exchange Agent to the tendering holders
of Old Notes, unless otherwise provided in this Letter of Transmittal, as soon
as practicable following the Expiration Date.

         2. PARTIAL TENDERS. Tenders of Old Notes will be accepted only in
denominations of $1,000 and any integral multiples in excess thereof. If less
than the entire principal amount of any Old Notes is tendered, the tendering
holder should fill in the principal amount tendered in the fourth column of the
box entitled "Description of






8 1/4% Senior Subordinated Notes Due 2011 (Old Notes)" above. The entire
principal amount of Old Notes delivered to the Exchange Agent will be deemed to
have been tendered unless otherwise indicated. If the entire principal amount of
all Old Notes is not tendered, then Old Notes for the principal amount of Old
Notes not tendered and the New Notes issued in exchange for any Old Notes
accepted will be sent to the holder at his or her registered address, unless a
different address is provided in the appropriate box on this Letter of
Transmittal, promptly after the Old Notes are accepted for exchange.

         3. SIGNATURES ON THE LETTER OF TRANSMITTAL; BOND POWERS AND
ENDORSEMENTS; GUARANTEE OF SIGNATURES. If this Letter of Transmittal (or
facsimile hereof) is signed by the record holder(s) of the Old Notes tendered
hereby, the signature must correspond with the name(s) as written on the face of
the Old Notes without alteration, enlargement or any change whatsoever.

         If this Letter of Transmittal (or facsimile hereof) is signed by the
registered holder or holders of Old Notes tendered and the New Notes issued in
exchange therefor are to be issued (or any untendered principal amount of Old
Notes is to be reissued) to the registered holder, the said holder need not and
should not endorse any tendered Old Notes, nor provide a separate bond power.

         If this Letter of Transmittal (or facsimile hereof) is signed by a
person other than the registered holder or holders of any Old Notes listed, such
Old Notes must be endorsed or accompanied by appropriate bond powers signed as
the name of the registered holder or holders appears on the Old Notes.

         If this Letter of Transmittal (or facsimile hereof) or any Old Notes or
bond powers are signed by trustees, executors, administrators, guardians,
attorneys-in-fact or officers of corporations or others acting in a fiduciary or
representative capacity, such persons should so indicate when signing, and,
unless waived by the Company, evidence satisfactory to the Company of their
authority so to act must be submitted with this Letter of Transmittal.

         Endorsements on Old Notes or signatures on bond powers required by this
Instruction 3 must be guaranteed by an Eligible Institution participating in a
recognized medallion signature guarantee program.

         Except as otherwise provided below, all signatures on this Letter of
Transmittal (or facsimile hereof) must be guaranteed by an Eligible Institution
participating in a recognized medallion signature guarantee program. Signatures
on this Letter of Transmittal need not be guaranteed if (i) this Letter of
Transmittal is signed by the registered holder(s) of the Old Notes tendered
herewith (including any participant in DTC whose name appears on a security
position listing as the owner of Old Notes) and such holder(s) have not
completed the box set forth herein entitled "Special Payments Instructions" or
the box entitled "Special Delivery Instructions" or (ii) such Old Notes are
tendered for the account of an Eligible Institution.

         4. SPECIAL ISSUANCE AND DELIVERY INSTRUCTIONS. Tendering holders should
indicate, in the applicable box or boxes, the name and address to which New
Notes or substitute Old Notes for principal amounts not tendered or not accepted
for exchange are to be issued or sent, if different from the name and address of
the person signing this Letter of Transmittal (or in the case of tender of the
Old Notes through DTC, if different from DTC). In the case of issuance in a
different name, the taxpayer identification or social security number of the
person named must also be indicated.

         5. TAX IDENTIFICATION NUMBER. Federal income tax law requires that a
holder whose offered Old Notes are accepted for exchange must provide the
Company (as payor) with his, her or its correct Taxpayer Identification Number
("TIN"), which, in the case of an exchanging holder who is an individual, is his
or her social security number. If the Company is not provided with the correct
TIN or an adequate basis for exemption, such holder may be subject to a $50
penalty imposed by the Internal Revenue Service (the "IRS"). In addition,
delivery to such holder of New Notes may be subject to backup withholding in an
amount equal to 31% of the gross proceeds resulting from the Exchange Offer. If
withholding results in an overpayment of taxes, a refund may be obtained. Exempt
holders (including, among others, all corporations and certain foreign
individuals) are not subject to these backup withholding and reporting
requirements.

         To prevent backup withholding, each exchanging holder must provide his,
her or its correct TIN by completing the Substitute Form W-9 enclosed herewith,
certifying that the TIN provided is correct (or that such holder is awaiting a
TIN) and that either (i) the holder is exempt from backup withholding, (ii) the
holder has not been notified by the IRS that he, she or it is subject to backup
withholding as a result of a failure to report all interest or dividends, or
(iii) the IRS has notified the holder that he, she or it is no longer subject to
backup withholding. In order to satisfy the Exchange Agent that a foreign
individual qualifies as an exempt recipient, such holder must submit a statement
signed under penalty of perjury attesting to such exempt status. Such statements
may be






obtained from the Exchange Agent. If the Old Notes are in more than one name or
are not in the name of the actual owner, consult the Substitute Form W-9 for
information on which TIN to report. If you do not provide your TIN to the
Company within 60 days, backup withholding will begin and continue until you
furnish your TIN to the Company.

         6. TRANSFER TAXES. The Company will pay all transfer taxes, if any,
applicable to the exchange of Old Notes pursuant to the Exchange Offer. If,
however, New Notes or Old Notes for principal amounts not tendered or accepted
for exchange are to be delivered to, or are to be registered or issued in the
name of, any person other than the registered holder of the Old Notes tendered
hereby, or if tendered Old Notes are registered in the name of any person other
than the person signing this Letter of Transmittal, or if a transfer tax is
imposed for any reason other than the exchange of Old Notes pursuant to the
Exchange Offer, then the amount of any such transfer taxes (whether imposed on
the registered holder or on any other person) will be payable by the tendering
holder.

         Except as provided in this Instruction 6, it will not be necessary for
transfer tax stamps to be affixed to the Old Notes listed in this Letter of
Transmittal.

         7. WAIVER OF CONDITIONS. The Company reserves the absolute right to
amend, waive or modify specified conditions in the Exchange Offer in the case of
any Old Notes tendered.

         8. MUTILATED, LOST STOLEN OR DESTROYED OLD NOTES. Any tendering holder
whose Old Notes have been mutilated, lost, stolen or destroyed should contact
the Exchange Agent at the address indicated herein for further instructions.

         9. REQUESTS FOR ASSISTANCE OR ADDITIONAL COPIES. Questions and requests
for assistance and requests for additional copies of the Prospectus or this
Letter of Transmittal may be directed to the Exchange Agent at the address
specified above. The telephone number for the Exchange Agent is (212) 815-6333.
Holders may also contact their broker, dealer, commercial bank, trust company or
other nominee for assistance concerning the Exchange Offer.



                                           (DO NOT WRITE IN SPACE BELOW)
- ----------------------------------------------------------------------------------------------------------------------
              CERTIFICATE                             OLD NOTES                               OLD NOTES
              SURRENDERED                              TENDERED                                ACCEPTED
- --------------------------------------- --------------------------------------  --------------------------------------
                                                                          

______________________________________________________________________________________________________________________

______________________________________________________________________________________________________________________

______________________________________________________________________________________________________________________

DELIVERY PREPARED BY: _________________ CHECKED BY: _____________ DATED:_________________







                   PAYOR'S NAME: IRON MOUNTAIN INCORPORATED



______________________________________________________________________________________________________________________
                                                                           

                           PART I -- PLEASE PROVIDE YOUR TIN IN THE
        SUBSTITUTE         BOX AT RIGHT AND CERTIFY BY SIGNING                    ____________________________
         FORM W-9          AND DATING BELOW                                          Social Security Number

                                                                                               OR

                                                                                  ----------------------------
                                                                                 Employer Identification Number

                           PART II -- CERTIFICATION--Under penalties of perjury, I certify that:
      DEPARTMENT OF
       THE TREASURY        (1)      The number shown on this form is my correct Taxpayer Identification Number (or I am waiting for
     INTERNAL REVENUE               a number to be issued to me), and
         SERVICE
                           (2)      I am not subject to backup withholding because (i) I am exempt from backup withholding, (ii) I
                                    have not been notified by the Internal Revenue Service ("IRS") that I am subject to backup
                                    withholding as a result of a failure to report all interest or dividends, or (iii) the IRS has
                                    notified me that I am no longer subject to backup withholding.
                           -----------------------------------------------------------------------------------------

                           CERTIFICATION INSTRUCTIONS--You must cross out item (2) in Part II above  if you have been notified by
     PAYER'S REQUEST       the IRS that you are subject to backup withholding because of underreporting interest or dividends on
       FOR TAXPAYER        your tax return. However, if after being notified by the IRS that you were subject to backup withholding
      IDENTIFICATION       you received another notification from the IRS that you are no longer subject to backup withholding, do
       NUMBER (TIN)        not cross out item (2).

                                                                                               PART III

                                                                                            Awaiting TIN  / /
                           Signature:__________________________________  Date:_________
                           Name (Please Print):________________________________________
______________________________________________________________________________________________________________________


         NOTE: FAILURE TO COMPLETE AND RETURN THE SUBSTITUTE FORM W-9 MAY RESULT
IN BACKUP WITHHOLDING OF 31% OF ANY PAYMENTS MADE TO YOU. PLEASE REVIEW THE
ENCLOSED GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION NUMBER ON
SUBSTITUTE FORM W-9 FOR ADDITIONAL DETAILS.

                     YOU MUST COMPLETE THE FOLLOWING CERTIFICATE
             IF YOU CHECKED THE BOX IN PART III OF SUBSTITUTE FORM W-9.

- --------------------------------------------------------------------------------

            CERTIFICATE OF AWAITING TAXPAYER IDENTIFICATION NUMBER

         I certify under penalties of perjury that a taxpayer identification
number has not been issued to me, and either (i) I have mailed or delivered an
application to receive a taxpayer identification number to the appropriate
Internal Revenue Service Center or Social Security Administration Office or (ii)
I intend to mail or deliver an application in the near future. I understand that
if I do not provide a taxpayer identification number within 60 days, 31% of all
reportable payments made to me thereafter will be withheld until I provide a
number.

- ----------------------------------------    ------------------------------------
           Signature                                    Date

- ----------------------------------------
      Name (Please Print)

- --------------------------------------------------------------------------------

EX-99.2

                                                                   EXHIBIT 99.2


                      FORM OF NOTICE OF GUARANTEED DELIVERY
                                       FOR
                    8 1/4% SENIOR SUBORDINATED NOTES DUE 2011
                                       OF
                           IRON MOUNTAIN INCORPORATED

     As set forth in the Prospectus, dated       , 1999 (the "Prospectus") of
Iron Mountain Incorporated (the "Company") and the accompanying Letter of
Transmittal and instructions thereto (the "Letter of Transmittal"), this form
or one substantially equivalent hereto must be used to accept the Company's
exchange offer (the "Exchange Offer") to purchase all of its outstanding 8
1/4% Senior Subordinated Notes Due 2011 (the "Old Notes") if (i) certificates
representing the Old Notes to be tendered for purchase and payment are not
lost but are not immediately available, (ii) time will not permit the Letter
of Transmittal, certificates representing such Old Notes or other required
documents to reach the Exchange Agent prior to the Expiration Date or (iii)
the procedures for book-entry transfer cannot be completed prior to the
Expiration Date. This form may be delivered by an Eligible Institution by
mail or hand delivery or transmitted, via telegram, telex or facsimile, to
the Exchange Agent as set forth below. All capitalized terms used herein but
not defined herein shall have the meanings ascribed to them in the Prospectus.

     THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON
               , 1999 UNLESS THE OFFER IS EXTENDED (THE "EXPIRATION DATE").
TENDERS OF OLD NOTES MAY BE WITHDRAWN AT ANY TIME PRIOR TO 5:00 P.M. ON THE
EXPIRATION DATE.

                               THE EXCHANGE AGENT:
                              The Bank of New York

                                         
  BY REGISTERED OR CERTIFIED MAIL:            BY HAND OR OVERNIGHT DELIVERY:
       The Bank of New York                       101 Barclay Street
     101 Barclay Street - 7E                     Corporate Trust Services
     New York, New York 10286                            Window
    Attention: Noriko Miyazaki                        Ground Level
      Reorganization Section                     New York, New York 10286
                                                 Attention: Noriko Miyazaki
                                                   Reorganization Section

  
                            BY FACSIMILE FOR ELIGIBLE
                                  INSTITUTIONS:
                                 (212) 815-4699

                             FOR CONFIRMATION AND/OR
                                INFORMATION CALL:
                                 (212) 815-6333

     DELIVERY OF THIS INSTRUMENT TO AN ADDRESS, OR TRANSMISSION VIA TELEGRAM,
TELEX OR FACSIMILE, OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID
DELIVERY.

     This form is not to be used to guarantee signatures. If a signature on
the Letter of Transmittal is required to be guaranteed by an "Eligible
Institution" participating in a recognized medallion signature guarantee
program under the instruction thereto, such signature guarantee must appear
in the applicable space provided in the signature box on the Letter of
Transmittal.




                                     -2-

TO:  THE BANK OF NEW YORK

Ladies and Gentlemen:

     The undersigned hereby tender(s) to the Company, upon the terms and
subject to the conditions set forth in the Exchange Offer and the Letter of
Transmittal, receipt of which is hereby acknowledged, the aggregate principal
amount of Old Notes set forth below pursuant to the guaranteed delivery
procedures set forth in the Prospectus.

     The undersigned understands that tenders of Old Notes pursuant to the
Exchange Offer may not be withdrawn after 5:00 p.m., New York City time on
the Expiration Date. Tenders of Old Notes may also be withdrawn if the
Exchange Offer is terminated without any such Old Notes being purchased
thereunder or as otherwise provided in the Prospectus.

     All authority herein conferred or agreed to be conferred by this Notice
of Guaranteed Delivery shall survive the death or incapacity of the
undersigned and every obligation of the undersigned under this Notice of
Guaranteed Delivery shall be binding upon the heirs, personal
representatives, executors, administrators, successors, assigns, trustees in
bankruptcy and other legal representatives of the undersigned.

                            PLEASE SIGN AND COMPLETE

                                       
Signature(s) of Registered Owner(s)       Names(s) of Registered Holder(s):
or Authorized Signatory:

- ---------------------------------         -------------------------------------

- ---------------------------------         -------------------------------------

- ---------------------------------         -------------------------------------

Aggregate Principal Amount of Old         Address:
Notes Tendered:

- ---------------------------------         -------------------------------------

- ---------------------------------         -------------------------------------

- ---------------------------------         -------------------------------------
                                          Area Code and
Certificate No.(s) of Old Notes           Telephone No.:
(if available):                                         -----------------------
                                          If Old Notes will be delivered by
- ---------------------------------         book-entry transfer at
- ---------------------------------         The Depository Trust Company,
- ---------------------------------         Insert DTC Book-entry Account
Date:-----------------------------        No.:---------------------------------
     -----------------------------            ---------------------------------



     This Notice of Guaranteed Delivery must be signed by the registered
holder(s) of Old Notes exactly as its (their) name(s) appear on certificates
for Old Notes, or by person(s) authorized to become registered holder(s) by
endorsements and documents transmitted with this Notice of Guaranteed
Delivery. If signature is by a trustee, executor, administrator, guardian,
attorney-in-fact, officer or other person acting in a fiduciary or
representative capacity, such person must provide the following information.

                      Please print name(s) and address(es)

Name(s):
        -----------------------------------

Capacity:
         -----------------------------------

Address(es):
            --------------------------------

DO NOT SEND OLD NOTES WITH THIS FORM.  NOTES SHOULD BE SENT TO THE EXCHANGE
AGENT TOGETHER WITH A PROPERLY COMPLETED AND DULY EXECUTED LETTER OF
TRANSMITTAL.




                                     -3-

                                    GUARANTEE
                    (NOT TO BE USED FOR SIGNATURE GUARANTEE)

     The undersigned, a member firm of a registered national securities
exchange or of the National Association of Securities Dealers, Inc. or a
commercial bank or trust company having an office or a correspondent in the
United States, hereby (a) represents that each holder of Old Notes on whose
behalf this tender is being made "own(s)" the Old Notes covered hereby within
the meaning of Rule 14e-4 under the Securities Exchange Act of 1934, as
amended, (b) represents that such tender of Notes complies with such Rule
14e-4, and (c) guarantees that, within three New York Stock Exchange trading
days from the date of this Notice of Guaranteed Delivery, a properly
completed and duly executed Letter of Transmittal (or a facsimile thereof),
together with certificates representing the Old Notes covered hereby in
proper form for transfer (or confirmation of the book-entry transfer of such
Old Notes into the Exchange Agent's account at The Depository Trust Company,
pursuant to the procedure for book-entry transfer set forth in the
Prospectus) and required documents will be deposited by the undersigned with
the Exchange Agent.

     THE UNDERSIGNED ACKNOWLEDGES THAT IT MUST DELIVER THE LETTER OF
TRANSMITTAL AND OLD NOTES TENDERED HEREBY TO THE EXCHANGE AGENT WITHIN THE
TIME PERIOD SET FORTH ABOVE AND THAT FAILURE TO DO SO COULD RESULT IN
FINANCIAL LOSS TO THE UNDERSIGNED.

Name of Firm:
             -------------------------     ---------------------------------
                                           Authorized Signature
Address:------------------------------

        ------------------------------     Name:----------------------------

- -------------------------------------
                                           Title:
                                                 ---------------------------

Area Code and Telephone No.:               Date:
                                                ----------------------------
- -------------------------------------