26 CFR §1.6107-2

1. (a)In general. The Commissioner may prescribe the form and manner of satisfying the requirements imposed by section 6107(a) and (b) and § 1.6107-1(a) and (b) in forms, instructions, or other appropriate guidance (see § 601.601(d)(2) of this chapter).
2. (b)Effective date. To the extent this section relates to section 6107(a) and § 1.6107-1(a), it applies to income tax returns and claims for refund presented to a taxpayer for signature after December 31, 2002. To the extent this section relates to section 6107(b) and § 1.6107-1(b), it applies after December 31, 2002, to returns and claims for refund for which the 3-year period described in section 6107(b) expires after December 31, 2002.