48 C.F.R. §§ 750.7106-4
Informal commitments may be formalized under certain circumstances to permit payment to persons who have taken action without a formal contract; for example, where any person, pursuant to written or oral instructions from an officer or official of the Agency and relying in good faith upon the apparent authority of the officer or official to issue such instructions, has arranged to furnish or has furnished property or services to the agency and/or to a foreign assistance contractor or subcontractor without formal contractual coverage for such property or services. Formalization of commitments under such circumstances normally will protect the foreign policy interests of the United States by assuring persons that they will be treated fairly and paid expeditiously.
48 C.F.R. §§750.7106-4