SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                     FORM 15

   Certification and Notice of Termination of Registration under 12(g) of the
      Securities Exchange Act of 1934 or Suspension of Duty to File Reports
       Under Sections 13 and 15(d) of the Securities Exchange Act of 1934.

                         Commission File Number 33-35500

                          CITIBANK (SOUTH DAKOTA), N.A.
                 on behalf of Standard Credit Card Trust 1990-6
           (Issuer in respect of the Standard Credit Card Trust 1990-6
              9 3/8% Class A Credit Card Participation Certificates
            and 9 5/8% Class B Credit Card Participation Certificates)
           -----------------------------------------------------------
             (Exact name of registrant as specified in its charter)

                           701 East 60th Street, North
                         Sioux Falls, South Dakota 57117
                                 (605) 331-2626
                    ----------------------------------------
           (Address, including zip code, and telephone number, including
               area code, of registrant's principal executive offices)

              9 3/8% Class A Credit Card Participation Certificates
              9 5/8% Class B Credit Card Participation Certificates
              -----------------------------------------------------
            (Title of each class of securities covered by this Form)

                                 Not Applicable
              ----------------------------------------------------
                  (Titles of all other classes of securities
                    for which a duty to file reports under
                       section 13(a) or 15(d) remains)

     Please place an X in the box(es) to designate the appropriate rule
provision(s) relied upon to terminate or suspend the duty to file reports:

Rule 12g-4(a)(1)(i)       [x]       Rule 12h-3(b)(1)(ii)      [ ]
Rule 12g-4(a)(1)(ii)      [ ]       Rule 12h-3(b)(2)(i)       [ ]
Rule 12g-4(a)(2)(i)       [ ]       Rule 12h-3(b)(2)(ii)      [ ]
Rule 12g-4(a)(2)(ii)      [ ]       Rule 15d-6                [x]
Rule 12h-3(b)(1)(i)       [x]

Approximate number of holders of record
as of the certification or notice date: 0

         Pursuant to the  requirements  of the Securities  Exchange Act of 1934,
Citibank (South Dakota), N.A. has caused this  certification/notice to be signed
on its behalf by the undersigned duly authorized person.

Dated as of: March 30, 1998
                                        By: /s/ Eugene D. Rowenhorst
                                        Name: Eugene D. Rowenhorst
                                        Title: Senior Vice President


Instruction:  This  form is  required  by Rules  12g-4,  12h-3  and 15d-6 of the
General Rules and  Regulations  under the  Securities  Exchange Act of 1934. The
registrant  shall file with the Commission three copies of Form 15, one of which
shall be manually signed.  It may be signed by an officer of the registrant,  by
counsel or by any other duly authorized person. The name and title of the person
signing the form shall be typed or printed under the signature.