It appears that Wikipedia does keep an archive ... https://en.wikipedia.org/wiki/Wikipedia:Viewing_and_restoring_deleted_pages https://en.wikipedia.org/wiki/Wi

It appears that Wikipedia does keep an archive ... https://en.wikipedia.org/wiki/Wikipedia:Viewing_and_restoring_deleted_pages https://en.wikipedia.org/wiki/Wikipedia:Viewing_and_restorin... However ... > A message by Wikipedia system administrator Brion Vibber from January 2007 warned that deleted revisions could theoretically be cleared without warning at any time, and a script exists to perform this function. However in practice they have only been cleared twice, both times due to technical issues – once on 3 December 2003, because the Wikipedia database was transferred to a new server, and once on 8 June 2004 due to a database crash. This is, of course, different from the revision history for an article, which shows each edit and is available for public inspection, e.g., ... https://en.wikipedia.org/w/index.php?title=Deep_learning&offset=&limit=500&action=history https://en.wikipedia.org/w/index.php?title=Deep_learning&off...