What does it mean to reissue patents in the United States?

P usually stands for patent, which means "patent". China patent application number system is as follows: category identification code A of invention patent document, publication specification A8 of invention patent application, publication specification of invention patent application (title page reprint) A9, publication specification of invention patent application (full-text reprint) B, invention patent specification B8, invention patent specification (title page reprint) B9, invention patent specification (full-text reprint) C 1-C7, and. U utility model patent specification U8 utility model patent specification (title page reprint) U9 utility model patent specification (full-text reprint) Y 1-Y7 utility model patent document type identification code part invalid announcement S design patent authorization announcement S9 design patent authorization announcement (full-text reprint) S 1-S7 design patent authorization announcement part invalid announcement S8 is reserved for the title page reprint of the design patent authorization announcement booklet.