31 U.S.C. § 9310: Individual sureties

If another applicable Federal law or regulation permits the acceptance of a bond from a surety that is not subject to sections 9305 and 9306 and is based on a pledge of assets by the surety, the assets pledged by such surety shall—(1) consist of eligible obligations described under section 9303(a); and (2) be submitted to the official of the Government required to approve or accept the bond, who shall deposit the obligations as described under section 9303(b).