The Fanon Purge was a consensus decision by the active users on the Sarna BattleTechWiki on 18 May 2011, calling for a change to that Wiki's policies. Whereas previously, fan fiction (Fanon) was welcome on Sarna BTW, it was now decided to migrate all Fan Fiction to this site (the BattleTech Fanon Wiki), and keep BTW strictly encyclopedic.

As a result, numerous pieces of fan fiction and their associated talk pages and graphic files were copied over to this site, and subsequently deleted on BTW.