2 C.F.R. § 3485.137
(b) If the ED Deciding Official grants an exception, the exception must be in writing and state the reason(s) for deviating from the Governmentwide policy in Executive Order 12549.
(Authority: E.O. 12549 (3 CFR 1986 Comp., p. 189); E.O. 12689 (3 CFR 1989 Comp., p. 235); sec. 2455, Pub. L. 103-355, 108 Stat. 3327 (31 U.S.C. 6101 note); 20 U.S.C. 1082, 1094, 1221e-3, and 3474)