What bookdealers really mean. A dictionary by Tom Congalton and Dan Gregory (Between the Covers), with additions from other sources
A proof that is uncorrected, which is probably why they call it that. The text of a book printed, and bound in softcovers for use by the author, editors, proofreaders, and favored reviewers. Often errors or earlier versions of text appear in these proofs, and reviewers are usually cautioned by the publisher not to quote from this version. Versions where the text has changed considerably are considered more desirable. Around 1976 some publishers, who had noticed that proofs had become collectible, began to distribute them more widely, to booksellers and others, as a sort of "party favor," and consequently the values of some (but not all) proofs eventually diminished.
Epreuve non corrigée