A distinctive mark, characteristic, or sound indicating identity, A letter, number, or symbol placed at the bottom of the first page on each sheet of printed pages of a book as a guide to the proper sequence of the sheets in binding, A letter or figure placed at the bottom of the first page of each sheet of a book or pamphlet, as a direction to the binder in arranging and folding the sheets, adjective_ distinctive, characteristic indicative of identity, transitive verb_ To mark with, or as with, a signature or signatures