19 U.S.C. § 2078 - U.S. Code - Unannotated Title 19. Customs Duties § 2078. Certification of reason for advance

A certificate by the Commissioner of Customs  1 stating the amount of an expenditure made from funds advanced and certifying that the confidential nature of the transaction involved renders it inadvisable to specify the details thereof or impracticable to furnish the payee's receipt shall be a sufficient voucher for the sum expressed to have been expended.