wikia (Fandom)

I've noticed that for some reason, unlike mediawiki and wikipedia, the Fandom link starting with wiki doesn't work here. Can you tell me why, and can you possibly add this link here?

That's because "Wikia" is a namespace here, so it can't be an interwiki prefix. For the same reason it's better to not use "Fandom". I think it used to be possible to go through Meta but the interwiki over there is no longer "local" so it doesn't redirect. I guess we could add "CentralWikia" as on m:IWM if there's an use for it.