During the Chuunin exam final battles, each contestant had a card that explained their level in the 5 disciplines - Taijutsu, Genjutsu, Ninjutsu, Blood and Ninja Tool (sometimes called Ninja Art). Naruto MUD to date only has 3 of these. I've listed blood examples, so I'll also go over Ninja Tools.
We don't really see a lot about the Ninja Tools, so its a bit difficult to do it. They always say "Ninja Art: <<<<>>>>" with whatever is in there. They seem to mostly be weapons or tools to use in some way.
Anyway I just thought I'd start a thread on it, for later expansion of the mud, if and when we decide to go beyond the 3 disciplines. Of course, given that Genjutsu is far from completed, its perhaps a bit early to be thinking too seriously about implementing things like this.