Authority26 U.S.C. 6001, 6011, 6061, 6071, 6091, 6161, and 7805. Section 156.6060-1 also issued under 26 U.S.C. 6060(a); Section 156.6081-1 also issued under 26 U.S.C. 6081(a); Section 156.6109-1 also issued under 26 U.S.C. 6109(a); Section 156.6109-2 also issued under 26 U.S.C. 6109(a); Section 156.6695-1 also issued under 26 U.S.C. 6695(b).