41 C.F.R. § 101-29.403-1
When the exceptions listed in § 101-29.402 do not apply and an applicable indexed product description is desired for use in procurement but does not meet an agency's essential needs, exceptions to the product description to effect procurement may be authorized as follows:
(c) Exceptions to Federal product descriptions that do not require prior approval under paragraphs (a) and (b) of this section may be authorized by the acquiring agency if:
(2) Notification of exception or recommendation for change to the Federal product description is sent promptly to the preparing activity and the General Services Administration (FCO), Washington, DC 20406.
(A statement of the exception with a justification and, where applicable, recommendation for revision or amendment to the description)