10 U.S.C. § 8805: Acceptance of Government checks outside the United States

Notwithstanding section 3302(a) of title 31, the Secretary of the Navy may authorize the officer in charge of any commissary store or ship’s store ashore located outside the United States to—(1) accept any Government check tendered by a retired member of the Navy or the Marine Corps, a member of the Navy Reserve or the Marine Corps Reserve, or a member of the Fleet Reserve or the Fleet Marine Corps Reserve, if the member is the payee of the check and the check is tendered in payment of amounts due from the member to the store; and (2) refund in cash any difference between the amount due and the amount of the tendered check.