Treasury Regulations (26 C.F.R.)
26 CFR § 1.66-5 — Effective date.
Sections 1.66-1 through 1.66-4 are applicable on July 10, 2003. In addition, § 1.66-4 applies to any request for relief filed prior to July 10, 2003, for which the Internal Revenue Service has not issued a preliminary determination as of July 10, 2003.
Source: official text