This page in a nutshell: An RfC found consensus to deprecate the Book namespace and delete all books therein, with undeletion available on request. See "How do I get a book undeleted?" below for instructions.

On 15 May 2021,an RfC was opened that proposed deprecating the Book namespace, and gave various options for what to do with the content in the namespace should consensus be found for deprecation.

The deprecation portion of the RfC was subsequentlyclosed on 24 May 2021 with consensus being found to deprecate.

Subsequently, the "options for action" portion wasclosed on 18 June 2021, with consensus being found to delete books within the namespace so long as undeletion was possible on request. Consensus was separately found for other options that were smaller in scope, such as preventing the namespace being indexed by search engines, but the deletion option superseded these.

Owing to technical restrictions, content cannot be undeleted from namespaces that do not exist (they would be located atSpecial:Badtitle/NS108:<book_name>, which cannot be accessed directly). Therefore, in order to ensure that content is retrievable as per the RfC finding, all books were moved to subpages ofWikipedia:Books/archive by a bot.

The booknamespace was removed from the English Wikipedia, on 13 July 2021.

On 3 August 2021, all books had been deleted.

Go toRequests for Undeletion, and enterWikipedia:Books/archive/<book_name> as the page to undelete - replacing<book_name> with the name of the book you want to restore.

An administrator will then restore the content to youruserspace.^{[note 1]}

The following was taken largely from the opening statement of the RfC linked above, with some copyedits and tense changes for clarity.

The Book namespace was introduced in 2009 as a way to download or print a collection of articles. To do this you useSpecial:Book to select a collection of articles you want in the book. divide them into chapters and choose some rendering settings. You can also give it a cover image, change the color of the book, choose rendering settings, and divide the articles into chapters.

After this was done you could either purchase a printed copy fromPediaPress or download it in a wide variety of formats including PDF using theOffline Content Generator.

Eventually the Offline Content Generator became outdated and unmaintainable. Bugs and security issues could no longer be fixed so the Wikimedia Foundation turned off the book rendering service on all Wikimedia wikis inOctober 2017. Since then, Wikipedia books have only been available either in physical form from PediaPress or throughMediaWiki2LaTeX (de:b:Benutzer:Dirk Huenniger/wb2pdf/manual). The issue with this is that we now require readers to visit a third party site to access our content and either purchase it or wait for a significant amount of time to get access to the book to render if MediaWiki2LaTeX even works properly for you. A large proportion of our books are too long to render and a good chunk of the rest have things like navboxes breaking the renderer and even if it in theory should work I've had times were it randomly stop or I can't download the book for unexplained reasons. If you want to do it locally (which I've heard works significantly better) you will have to do it on Linux or set up a virtual machine. After investing a few hours trying to do this I gave up so I haven't tested that personally. If you want a PDF of an article I would instead suggest using the "Download as PDF" option in the side bar which can reliably give you a PDF version in seconds.

At the time of the deprecation RfC, the namespace had pageviews on the order of a popular portal likePortal:South Africa spread out over slightly more than 6000 pages. During a normal month without significant editor activity most books didn't get a single view and just 1.5% of books got any daily pageviews. The most popular one, now located atUser:David Eppstein/Fundamental Data Structures, got just 15.

There have been several previous initiatives to hide books from readers, the biggest three being2019 removal of book creator from side bar and suppression of many links,2021 removal of remaining links and2021 deletion of some book related templates. The latter two were basically unanimous decisions.

Books can be created in userspace asCategory:User namespace book pages. TheBook: namespace has been disabled by sysadmins; a title likeBook:Foo is now just considered a mainspace article.

PediaPress links to a few of our books at theCatalog, which may or may not be possible to retain if the books are deleted on Wikipedia. It would continue to be possible to use PediaPress as long asSpecial:Book isn't removed. Either by not saving the book on wiki and saving it at PediaPress or by saving it user space.

This link lists any remaining subpages of this page.Wikipedia:Books/archive/All pages lists all subpages that existed before deletion started.