48 C.F.R. § 217.7302
(a) Whenever practicable, include a requirement for contractor identification of sources of supply in all contracts for the delivery of supplies. The identification shall include—
(3) The item identification number used by—
(b) The requirement in paragraph (a) of this section does not apply to contracts that are—
[56 FR 36345, July 31, 1991, as amended at 64 FR 2597, Jan. 15, 1999; 88 FR 6583, Jan. 31, 2023]