Books discarded from library collections are not generally considered collectible. If the ex-library (sometimes abbreviated ex-lib) designation applies, it should always be included in the book's description. (Note that the term ex libris means "from the library of..." and usually denotes a book from a private collection. It does not mean the same thing as ex-library.)

Books described as "ex-library, with all the usual markings" or similar language may contain some or all of the characteristic defacements shown below.

Library due date slip and card pocket.

Due date slips and card pockets. If these have been removed, they may leave behind glue stains or torn and abraded paper.

Library ownership stamp.

Ownership stamps. These will usually appear multiple times in a book. They may be found on the title page, text pages, upper or lower page edges, or the inside covers.

Library cataloging codes.

Cataloging Information. Notes and codes used for cataloging the book.

Library bar-code control strip and Withdrawn stamp.

Inventory control strips and withdrawn stamps. Books that are obviously from a library collection but that do not bear a withdrawn stamp should be purchased with caution, since they may not have been actually deacquisitioned.