1 C.F.R. § 21.52
(a) United States Code. All citations to statutory authority shall include a United States Code citation, where available. Citations to titles of the United States Code, whether or not enacted into positive law, may be cited without Public Law or U.S. Statutes at Large citation. For example:
Authority: 10 U.S.C. 501.
Authority:Sec. 5, Pub. L. 89-670, 80 Stat. 935 (49 U.S.C. 1654); sec. 313, Pub. L. 85-726, 72 Stat. 752 (49 U.S.C. 1354).
[54 FR 9682, Mar. 7, 1989]