As the name implies, it is a slip of paper canceling or covering something that was originally printed on the title page or last page, most likely a colophon or some identification of the first printer or publisher. In a few instances, the cancel slip is pasted on a blank space on the suelta in which case it is added by the bookseller who want to show ownership.

Cancel slips on sueltas are usually an indication of the sale of stock from one printer to another during the transfer of a business. The new owner pastes his printed slip over some part of the title page or over the colophon of the previous printer. Many cancel slips survive in poor condition: partly torn, partly rubbed, damaged in various other ways. They may also have fallen off and left glue marks. If these marks were washed off later, there may be no trace of the original cancel slip.

See also: colophon, imprint