(a) The rules in this part implement 39 U.S.C. 601, which describes certain circumstances in which letters may be carried out of the mail.

(b) Notwithstanding placement in Postal Service chapter I of this title, the following provisions in parts 310 and 320 of this title are within the scope of this part and the Commission has the authority to interpret them:

(1) Section 310.1 of this title;

(2) Sections 310.2(b)(1) and (2) of this title; and

(3) Sections 320.1 through 320.8 of this title.

(c) In the event of a conflict between 39 U.S.C. 601 and applicable regulations under parts 310 and 320 of this title, 39 U.S.C. 601 shall supersede any other generally applicable requirements.