Section 25.2703-1 applies to any right or restriction created or substantially modified after October 8, 1990, and is effective as of January 28, 1992. With respect to transfers occurring prior to January 28, 1992, and for purposes of determining whether an event occurring prior to January 28, 1992 constitutes a substantial modification, taxpayers may rely on any reasonable interpretation of the statutory provisions. For these purposes, the provisions of the proposed regulations and the final regulations are considered a reasonable interpretation of the statutory provisions.

[T.D. 8395, 57 FR 4274, Feb. 4, 1992]