Permissible marks and enclosures

§ 4555. Permissible marks and enclosures The sender may not place on or enclose in fourth class mail marks that have the character of personal correspondence, but the following marks and enclosures may be placed on or in fourth class mail when space is left on the address side sufficient for a legible address and necessary stamps— (1) the sender’s name, occupation, and address, preceded by the word “from”, and directions for transmission, delivery, forwarding, or return; (2) marks other than by written or printed words to call attention to words or passages in the text; (3) correction of typographical errors; (4) a simple manuscript dedication or inscription not of the nature of personal correspondence on the blank leaves or cover of a book or other printed matter; (5) matter mailable as third class mail printed on the wrapper, envelope, tag or label; (6) marks, numbers, names or letters for the purpose of description printed or written on the wrapper or cover; (7) the words “Please Do Not Open Until Christmas” or words to that effect on the package, wrapper or envelope enclosing the same or on a tag or label attached thereto; (8) corrections on proof sheets: (9) manuscript accompanying proof sheets; and (10) matter mailable as third class mail.