- "JK Rowling's reaction is that she is very flattered by the fact there is such great interest in her Harry Potter series and that people take the time to write their own stories. Her concern would be to make sure that it remains a non-commercial activity to ensure fans are not exploited and it is not being published in the strict sense of traditional print publishing."
- ―Spokesperson for the Christopher Little literary agency about Harry Potter fan fiction[src]
Fanon refers to any fan-made fiction. It is synonymous with fan fiction (which, itself, is often shortened to fanfic or just a fic). Both are unlicensed stories, written by a fan, which takes place in an established fictional universe, such as the Harry Potter universe. Such fiction is un-recognized by J.K. Rowling and is therefore non-canon, however, Rowling has given her blessing to fans who want to write fan-fiction in her universe – as long as it isn't published traditionally.
The word itself is a portmanteau of fan and canon.
Fanon on Ilvermorny Wiki
On Ilvermorny Wikia, fanon is restricted to the North American continent, and does not deal with the British setting of most traditional Harry Potter fan sites. Nevertheless, it uses some material from Rowling's canon, such as its namesake: Ilvermorny School of Witchcraft and Wizardry.