Endorsements on penalty covers

§ 4153. Endorsements on penalty covers (a) Except as otherwise provided in this section, penalty covers shall bear, over the words “Official Business” an endorsement showing the name of the department, bureau or office from which, or officer from whom, it is transmitted. The penalty for the unlawful use of all penalty covers shall be printed thereon. 74 Stat. 661 (b) The Postmaster General shall prescribe the endorsement to be placed on covers mailed under paragraphs (1) (E), (2), and (3) of section 4152 (a) of this title.