19 C.F.R. § 10.104
The entry of articles brought into the United States temporarily by an agency or office of the United States Government and claimed to be exempt from duty under Chapter 98, Subchapter XIII, Heading 9813, Harmonized Tariff Schedule of the United States (HTSUS), shall be made on Customs Form 7501, or its electronic equivalent. No bond shall be required if the agency or office files a stipulation in the form set forth in § 141.102(d) of this chapter. In those cases in which the provisions of Chapter 98, Subchapter XIII, HTSUS (19 U.S.C. 1202 ), are not met, however, the Center director will proceed as if a bond had been filed to cover the particular importation. Articles temporarily imported by a Government agency or office under this section are entitled to immediate delivery under the procedures set forth in § 10.101 .
19 C.F.R. §10.104