Pub. L. 86-682, tit. 39, pt. I, ch. 1, sec. 1
Definitions
§ 1. Definitions As used in this title— “Department” means the Post Office Department, continued by section 301 of this title, and the postal field service of the Post Office Department; “postal field service” or “field postal service” includes all operations and organization units of the Department, other than the departmental operations and organization units in the headquarters offices of the Department at the seat of the Government, and includes postal inspectors assigned to the headquarters offices of the Department at the seat of the Government; “departmental service” means the administrative headquarters of the Department and its branches as distinguished from the postal field service; “revenue of the Department” means all funds of the United States, other than trust funds, received by the Department from any source in the exercise of any power or function vested in it, including, but not limited to— (i) unclaimed money in dead letters for which an owner cannot be found; (ii) unclaimed money taken from the mail by robbery, theft, or otherwise, which may come into the hands of an agent or employee of the United States or any other person; 74 Stat. 579 (iii) fines, penalties, and forfeitures, imposed for a violation of the postal laws, except such part as may by law belong to the informer or party prosecuting for the same; (iv) money derived from the sale of wastepaper or other public property of the Department.