Out of print refers to an item, typically a book (see: out-of-print book), but can include any print or visual medium or sound recording, that is no longer being published.
The abbreviation OOP (also OP) is a more general term that encompasses craft, hobby, toy, and collectable items that are out of production.
An item goes out of print when a publisher does not reprint, re-press, or reissue after all copies have been sold to retailers. Reasons may include:
Out of print items are often pursued by collectors through aftermarket retailers such as used book stores, record shops, and online auction sites. Sellers of out of print merchandise on auction sites will typically include "OOP" or its equivalent in product descriptions. The designation is sometimes misappropriated—an example is in keyword stuffing, where the acronym is used to generate numerous search results even as it does not apply to the items retrieved. The abbreviation is sometimes placed in descriptions of items whose publication or production status is unclear (such as DVDs said to be returning to the "Disney Vault") to affect interest in the product.