39 C.F.R. § 3030.160 – Applicability.

(a) This subpart allocates rate authority to address the effects of decreases in the density of mail as measured by the sources identified in § 3030.161. The calculation of the additional rate authority corresponding to the change in density is described in § 3030.162.
(b) The Postal Service shall file a notice with the Commission by December 31 of each year that calculates the amount of density rate authority that is eligible to be authorized under this subpart.
(c) The Commission shall review the Postal Service's notice and determine how much, if any, rate authority will be authorized under this subpart. Any rate authority allocated under this subpart:
1. (1) Shall be made available to the Postal Service as of the date of the Commission's determination;
2. (2) Must be included in the calculation of the maximum rate adjustment authority in the first generally applicable rate adjustment filed after the Commission's determination; and
3. (3) May be used to generate unused rate authority, if unused, within 12 months of the Commission's announcement.