39 CFR § 3022.2
Scope and nature of complaints
November 6, 2020
Any interested person (including a duly appointed officer of the Commission representing the interests of the general public) may file a written complaint with the Commission if that person believes that the Postal Service is not operating in conformance with:
(a) The provisions of 39 U.S.C. chapter 36, or 39 U.S.C. 101(d), 401(2), 403(c), 404a, or 601; or
(b) Any rule, order, or other regulatory requirement based on any of these statutory provisions.