48 C.F.R. § 13.305-4
(e) The individual authorized to make purchases using imprest funds or third party drafts shall—
(1) Furnish to the imprest fund or third party draft cashier a copy of the document required under paragraph (a) of this subsection annotated to reflect—
(2) Require the supplier to include with delivery of the supplies an invoice, packing slip, or other sales instrument giving—