out of print
In print publishing, when new copies of a book are no longer available for purchase.
A traditional publishing contract will usually define "out of print" as being a measurable period of time after the book has become unavailable (for example, six months). At this point, the publishing rights typically revert to the author (though sometimes only if the author makes a formal request).
In e-publishing, books cannot be "out of print", since they are not printed. However, the term is still used in situations where the book is no longer legally sold, such as if the publisher or author shut down operations, or if the book is withdrawn from the market for some reason.