Section 20.7520-4 - Transitional rules(a)Reliance. If the valuation date is after April 30, 1989, and before June 10, 1994, an executor can rely on Notice 89-24, 1989-1 C.B. 660, or Notice 89-60, 1989-1 C.B. 700 (See § 601.601(d)(2)(ii) (b) of this chapter), in valuing the transferred interest.(b)Effective date. This section is effective as of May 1, 1989.