User blog comment:LovelyChrys/Fanfic on this wikia?/@comment-26308-20120524135218

No. GRRM doesn't allow fanfic, HBO isn't too keen on it and the GoT Wiki enjoys a good relationship with both HBO and GRRM, so we're not going to do anything to upset that.

There is a GoT fanfic-specific Wiki, as mentioned above, and lots of other venues (particularly on Livejournal) where it can be posted, so it can be done there.