39 CFR 263.3: Responsibility.

(a) Records Office. Records Office has the responsibility for providing for the establishment of retention schedules and has the authority to approve them. Furthermore, that office has the authority to dispose of Postal Service records by transfer or destruction.

(b) Custodians. Custodians are responsible for the retention and prompt disposal of records in their custody and for delegating in writing, persons to perform these duties.