Labels pasted in books to mark their ownership and sometimes to indicate their location in a library. Private bookplates are often ornate or artistic: simpler and smaller ones bearing merely the owner's name are called "book labels." They are usually pasted on the front endpaper of books. (From Harrod, The Librarians' Glossary and Reference Book, 4th rev ed & Random House Unabridged Dictionary, 2d ed)
A bookplate, also known as ex-libris, is a decorative label or plate found in books, typically bearing the name of the owner and often designed by an artist, used to indicate ownership and pride.