39 C.F.R. § 761.7
No formal assignment shall be required for the conversion to book-entry Postal Service securities of registered Postal Service securities held by a Reserve Bank (in either its individual capacity or as fiscal agent of the United States) on the effective date of this part for any purpose specified in § 761.3(a) . Registered Postal Service securities deposited thereafter with a Reserve Bank for any purpose specified in § 761.3 shall be assigned for conversion to book-entry Postal Service securities. The assignment, which shall be executed in accordance with the provisions of part 760 of this subchapter and subpart F of 31 CFR part 306, so far as applicable, shall be to "Federal Reserve Bank of ------ as fiscal agent of the United States acting on behalf of the Postal Service for conversion to book-entry Postal Service securities."
39 C.F.R. §761.7