
<PAGE>
 
                                                                       EXHIBIT H

                            DART GROUP CORPORATION
                               3300 75TH AVENUE
                           LANDOVER, MARYLAND  20785


                           CONFIDENTIALITY AGREEMENT

     You, the undersigned, have expressed an interest in a possible purchase of,
merger with or similar transaction involving, Dart Group Corporation and/or one
or more of its subsidiaries (collectively, the "Company").  In connection with
your analysis of a possible negotiated transaction with the Company, you have
requested certain oral and written information concerning the Company from
officers, directors, employees, representatives, advisors and/or agents of the
Company.  In consideration of furnishing you with such information, you agree
to, and agree to cause your affiliates to comply with, the following terms of
this Confidentiality Agreement:

(1)  The Evaluation Material (as defined below) will be used solely for the
     purpose of evaluating a possible transaction between the Company and you
     relating to the purchase by you of the Company, and will not be used in any
     way directly or indirectly detrimental to the Company or for any other
     purpose.  All the Evaluation Material will be kept confidential by you and
     your legal and financial advisors, except that you may disclose the
     Evaluation Material or portions thereof to those of your directors,
     officers, employees, representatives and agents and to those
     representatives of your legal and financial advisors (the persons to whom
     such disclosure is permissible being collectively called "Representatives")
     who need to know such information for the purpose of evaluating your
     possible acquisition of the Company (it being understood that each such
     Representative will be informed of the confidential nature of the
     Evaluation Material and will agree to be bound by this agreement).  You
     agree to be responsible for any breach of this agreement by any of the
     Representatives.  You will keep a list of all persons (indicating their
     position and affiliation) who have received any of it.  In the event that
     you or any of the Representatives is requested or required (by deposition,
     interrogatory, request for documents, subpoena, civil investigative demand
     or similar process or by law or rule of a stock exchange or similar entity)
     to disclose any of the Evaluation Material, you or such Representative, as
     the case may be, shall provide the Company with prompt prior notice of such
     request or requirement so that the Company may seek a protective order or
     other appropriate remedy or, if appropriate, waive compliance with the
     terms of this agreement.  In the event that such protective order or other
     remedy is not obtained, or that the Company waives compliance with the
     provisions hereof, (i) you or such Representative, as the case may be, may
     disclose to any tribunal only that portion of the Evaluation Material which
     you are advised by written opinion of

                                      H-1
<PAGE>
 
Richfood Holdings, Inc.
Page 2 -- February __, 1998
 
     your counsel is legally required to be disclosed or else stand liable for
     contempt or suffer other censure or penalty, and shall exercise reasonable
     efforts to obtain assurance that confidential treatment will be accorded
     such Evaluation Material and (ii) you shall not be liable for such
     disclosure unless such disclosure to such tribunal was caused by or
     resulted from a previous disclosure by you or any Representative not
     permitted by this agreement.  The term "person" as used in this agreement
     with be interpreted broadly to include, without limitation, any
     corporation, company, partnership or individual.

(2)  The term "Evaluation Material" as used in this agreement shall mean all
     information and documents, whether in written or oral form, which have been
     furnished by the Company, or any employee, officer, or financial or legal
     advisor to the Company (the "Disclosing Party"), to you or any of the
     Representatives, whether furnished or otherwise disclosed before or after
     the date of this agreement, together with all analyses, compilations,
     studies or other documents, records or data prepared by you or any of the
     Representatives which contain or otherwise reflect or are generated from
     such information and documents.  The term "Evaluation Material" does not
     include any information which (i) at the time of disclosure is generally
     available to and known by the public (other than as a result of a
     disclosure directly or indirectly by you or any of the Representatives not
     permitted by this agreement), (ii) was available to you on a
     nonconfidential basis from a source that is not known by you to be bound by
     a confidentiality agreement with any Disclosing Party or otherwise
     prohibited from transmitting or disclosing the information by a
     contractual, legal or fiduciary obligation, (iii) has been independently
     developed by you without violation of any obligation under this agreement
     or use of any Evaluation Material or (iv) became available to you on a non-
     confidential basis or has been independently developed by you in your
     capacity as wholesale supplier to Shoppers Food Warehouse Corp.
     ("Shoppers").

(3)  If you determine not to seek to proceed with a transaction with the
     Company, you will promptly inform the Company, and you and your
     Representatives shall promptly either (i) destroy all copies of the written
                                    ------                                      
     Evaluation Material in your or their possession or under your or their
     custody or control (including that stored in any computer, word processor
     or similar device) and confirm such destruction to the Company in writing
     or (ii) return to the Company all copies of the Evaluation Material
     furnished to you by or on behalf of the Company in your possession or in
     the possession of your Representatives.  Any oral Evaluation Material will
     continue to be held subject to the terms of this agreement.

                                      H-2
<PAGE>
 
Richfood Holdings, Inc.
Page 3 -- February __, 1998
 
(4)  Except as required by law or by the rules and regulations of any stock
     exchange on which your stock is listed and only to the extent required by
     such law or rules and regulations as so advised in writing by counsel, you
     will not, and will direct and cause the Representatives not to, without the
     prior written consent of the Company, disclose to any person (i) that the
     Company is contemplating a sale, (ii) that any investigations, discussions
     or negotiations are taking place concerning a possible transaction between
     the Company and you, (iii) that you have requested or received Evaluation
     Material from any Disclosing Party, or (iv) any of the terms, conditions or
     other facts with respect to any such possible transaction, including the
     status thereof.

(5)  Until the earliest of (i) the execution by you of a definitive purchase and
     sale agreement (the "Sale Agreement"); (ii) an acquisition of the Company
     by a third party; or (iii) two years from the date of this agreement, you
     agree not to initiate or maintain contact (except for those contacts made
     in the ordinary course of business) with any officer, director, employee,
     representative, or agent of the Company or any of its subsidiaries
     regarding its business, assets, operations, prospects or finances, except
     with the express written permission of the Company.  It is understood that
     the Company will arrange for appropriate contacts for due diligence
     purposes.  It is further understood that all (a) communications regarding
     this possible transaction, (b) requests for additional information, (c)
     requests for facility tours or management meetings and (d) discussions or
     questions regarding procedures will be submitted or directed to Senator
     Richard Stone.  You further agree that for a period of one year from the
     date hereof, you will not solicit for hire any of the employees of the
     Company with whom you have had contact during the period of your
     investigation or who became known to you in the course of your
     consideration of a possible transaction with the Company, provided,
     however, that the foregoing will not be deemed to prevent you from (1)
     conducting general solicitations of employment published in a journal,
     newspaper or other publication of general circulation or in trade
     publications or other similar media and which, in any case, are not
     directed specifically toward such employees, or (2) negotiating with or
     employing any such employee who initiates contacts with you on an
     unsolicited basis.

(6)  You understand and acknowledge that the Company is not making any
     representation or warranty, express or implied, as to the accuracy or
     completeness of the Evaluation Material, and the Company, its officers,
     directors, employees, stockholders, owners, affiliates, advisors or agents
     expressly disclaims any and all liability to you or any other person that
     may be

                                      H-3
<PAGE>
 
Richfood Holdings, Inc.
Page 4 -- February __, 1998

     based upon or relate to (i) the use of the Evaluation Material by you or
     any of the Representatives or (ii) any errors therein or omissions
     therefrom.  Only those particular representations or warranties, if any,
     that are made to a purchaser in a definitive Sale Agreement when, as, and
     if it is executed, and subject to such limitations and restrictions as may
     be specified in such Sale Agreement, will have any legal effect.

(7)  For a period of two years from the date hereof, unless specifically
     requested or permitted in writing in advance by the Company, you and your
     affiliates (as defined in Rule 12b-2 under the Securities Exchange Act of
     1934, as amended (the "Exchange Act")) that are under your control will not
     (and you and they will not advise, assist, participate with or encourage
     others to), directly or indirectly, in any manner, effect or seek, offer,
     propose (whether publicly or otherwise) to:

     (i)    make any public announcement with respect to, or submit any proposal
            for, a transaction between the Company or any of its security
            holders and you (and/or any of your affiliates), whether or not any
            other parties are also involved, directly or indirectly, in such
            proposal or transaction, unless such proposal is directed and
            disclosed solely to the Board of Directors of the Company or its
            designated representatives, and the Company shall have requested in
            writing in advance the submission of such proposal (and shall have
            consented in writing, in advance, in the case of any such proposal
            from or involving parties in addition to or other than you, to the
            involvement of such additional or other parties);

     (ii)   by purchase or otherwise, through your affiliates or otherwise,
            alone or with others, acquire, offer to acquire, or agree to
            acquire, ownership (including, but not limited to, beneficial
            ownership as defined in Rule 13d-3 under the Exchange Act) of any
            assets or business of the Company (other than in the ordinary course
            of your business as wholesale supplier to Shoppers) or of any voting
            or other securities or direct or indirect rights (including
            convertible securities) or options to acquire such ownership (or
            otherwise act in concert with any person which so acquires, offers
            to acquire, or agrees to acquire);

     (iii)  make, or in any way participate directly or indirectly in, any
            "solicitation" of "proxies" (as such terms are used in the proxy
            rules of the Securities and Exchange Commission) to vote, or seek to
            advise or influence any

                                      H-4
<PAGE>
 
Richfood Holdings, Inc.
Page 5 -- February __, 1998
 
            person with respect to the voting of, any voting securities of the
            Company or any of its affiliates;

     (iv)   form, join or in any way participate in a "group" (within the
            meaning of Section 13(d)(3) of the Exchange Act) with respect to any
            voting securities of the Company or any of its affiliates;

     (v)    otherwise, alone or in concert with others, seek to influence or
            control the management or policies of the Company or any of its
            affiliates (other than in the ordinary course of your business as
            wholesale supplier to Shoppers);

     (vi)   deposit securities of the Company or any of its subsidiaries into a
            voting trust;

     (vii)  except as required by law or by the rules and regulations of any
            stock exchange on which your stock is listed and only to the extent
            required by such law or rules and regulations as so advised in
            writing by counsel, take any action which might require the Company
            to make a public announcement regarding (A) the possibility of a
            business combination or merger involving, or a sale or other
            disposition of, the Company or its subsidiaries or any of its voting
            securities or a material portion of its assets or any
            recapitalization, restructuring, liquidation, dissolution, purchase
            or sale of a substantial portion of the assets of, or other
            extraordinary transaction with respect to the Company or any of its
            subsidiaries or (B) any of the types of matters set forth in (i)-
            (vi) above;

     (viii) except as required by law or by the rules and regulations of any
            stock exchange on which your stock is listed and only to the extent
            required by such law or rules and regulations as so advised in
            writing by counsel, disclose to any third party any intention, plan
            or arrangement inconsistent with the foregoing; or

     (ix)   enter into any discussions, negotiations, arrangements or
            understandings with any third party with respect to any of the
            foregoing. You and your affiliates agree not to approach or request
            the Company or its subsidiaries (or any of their respective
            directors, officers, employees or agents), directly or indirectly,
            to amend or waive any provision of this paragraph (7) (including
            this sentence).

                                      H-5
<PAGE>
 
Richfood Holdings, Inc.
Page 6 -- February __, 1998
 
     You and your affiliates under your control agree to notify the Company if
     you or one or more of such affiliates is approached by a third party
     concerning the participation of you and/or the third party in a transaction
     or activity described in this paragraph (7) and you and such affiliates
     under your control agree to inform the Company of the nature of each
     contact with such third parties and the identities of the third parties
     involved.

(8)  You and your affiliates under your control hereby acknowledge that you are
     aware and that your officers, directors, employees, advisers and/or agents
     involved in the possible transaction contemplated herein have been advised
     that the United States securities laws prohibit any person who has material
     non-public information about a company from purchasing or selling
     securities of such company.

(9)  You also understand and agree that no contract or agreement providing for
     the sale of the Company shall be deemed to exist between you and the
     Company unless and until a definitive Sale Agreement has been executed and
     delivered by you and the Company, and you hereby waive, in advance, any
     claims (including, without limitation, breach of contract) in connection
     with the sale of the Company unless and until a definitive Sale Agreement
     has been executed and delivered by you and the Company.  You also agree
     that unless and until a definitive Sale Agreement has been executed and
     delivered, neither the Company, nor its stockholders or owners has any
     legal obligation of any kind whatsoever with respect to any such
     transaction by virtue of this agreement or any other written oral
     expression with respect to such transaction except, in the case of this
     agreement, for the matters specifically agreed to herein.  For purposes of
     this paragraph, the term "definitive Sale Agreement" does not include an
     executed letter of intent or any other preliminary written agreement, nor
     does it include any written or verbal acceptance of an offer or bid on your
     part.  You further understand that (i) the Company shall be free to conduct
     the process for the sale of the Company as it, in its sole discretion shall
     determine (including, without limitation, negotiating with any of the
     prospective buyers and entering into a definitive Sale Agreement without
     prior notice to you or any other person), (ii) any procedures relating to
     such sale may be changed at any time without notice to you or any other
     person and (iii) you shall not have any claims whatsoever against the
     Company, or any of its respective directors, officers, stockholders,
     owners, affiliates, representatives, advisors or agents arising out of or
     relating to the sale of the Company (other than those as against the
     parties to a definitive Sale Agreement with you in accordance with the
     terms thereof).  Neither this paragraph nor any other provision in this

                                      H-6
<PAGE>
 
Richfood Holdings, Inc.
Page 7 -- February __, 1998
 
     agreement can be waived or amended except by written consent of the
     Company, which consent shall specifically refer to this paragraph (or such
     other provision) and explicitly make such waiver or amendment.  Each party
     agrees that nothing in this agreement shall in any way affect, or
     constitute the waiver of any rights under, any supply agreements that may
     be in effect from time to time between you and Shoppers.

(10) You agree that money damages would not be a sufficient remedy for any
     breach of this agreement and that the Company shall be entitled to
     equitable relief, including injunction and specific performance, in the
     event of any breach of the provisions of this agreement, in addition to all
     other remedies available to the Company at law or in equity.  You also
     hereby irrevocably and unconditionally consent to submit to the exclusive
     jurisdiction of the courts of the State of Maryland and of the United
     States of America located in the State of Maryland for any actions, suits
     or proceedings arising out of or relating to this agreement and the
     transactions contemplated hereby (and you agree not to commence any action,
     suit or proceeding relating thereto except in such courts), and further
     agree that service of any process, summons, notice or document by U.S.
     registered mail to your address set forth below shall be effective service
     of process for any action, suit or proceeding brought against you in any
     such court.  You hereby irrevocably and unconditionally waive any objection
     to the laying of venue of any action, suit or proceeding arising out of
     this agreement or the transactions contemplated hereby in the courts of the
     State of Maryland, and hereby further irrevocably and unconditionally waive
     and agree not to plead or claim in any such court that any such action,
     suit or proceeding brought in any such court has been brought in an
     inconvenient forum.

(11) It is further understood that no failure or delay in exercising any right,
     power or privilege hereunder will operate as a waiver thereof, nor will any
     single or partial exercise thereof preclude any other or further exercise
     thereof or the exercise of any other right, power or privilege hereunder.

(12) This agreement is for the benefit of the Company and its successors and
     assigns.  The rights of the Company under this Agreement may be assigned in
     whole or in part to any purchaser of the Company, which purchaser shall be
     entitled to enforce this Agreement to the same extent and in the same
     manner as the Company is entitled to enforce the Agreement.  This agreement
     and all controversies arising from or relating to performance under this
     agreement shall be governed by and construed in accordance with the laws of
     the State of

                                      H-7
<PAGE>
 
Richfood Holdings, Inc.
Page 8 -- February __, 1998

     Maryland, without giving effect to its conflicts of laws and principles.
     This agreement supersedes the Confidentiality Agreement, dated as of March
     14, 1997, by and among you, the Company and Shoppers, which agreement shall
     be of no further force and effect.

(13) If any legal action is brought for the enforcement of the Agreement, or
     because of an alleged dispute, breach, default or misrepresentation in
     connection with any of the provisions of this Agreement, the prevailing
     party or parties shall be entitled to recover his, its or their reasonable
     attorneys' fees and other costs incurred in such legal action, in addition
     to any other relief to which he, it or they may be entitled.

     If you agree with the foregoing, please sign a copy of this facsimile
letter and return to me.  Your return to me of a signed facsimile copy will
thereupon constitute our agreement with respect to the subject matter of this
letter.


                                    Very truly yours,

                                    DART GROUP CORPORATION


                                    /s/ Richard B. Stone
                                    --------------------
                                    Richard B. Stone
                                    Chairman and Chief Executive Officer

                                      H-8
<PAGE>
 
Richfood Holdings, Inc.
Page 9 -- February __, 1998
 
AGREED TO and ACCEPTED THIS
_____ DAY OF FEBRUARY, 1998


RICHFOODS HOLDINGS, INC.


By: 
   ----------------------------
     Name:
          ---------------------
     Title:
           --------------------

Address:  
        -----------------------

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

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

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

                                      H-9
