Pokemon with > 600 BST are banned. Excluding Kekking/Slaking. Event Pokemon are allowed.
Excluding Kekking again, Pokemon with >= 580 BST are banned. Including event Pokemon and pseudo-legends.
Lati@s with kokoro-no-shizuku/soul dew are counted as event Pokemon. Without the item they don't count. Phione also counts as an event Pokemon.
Clauses: item, species, self-ko, sleep. That's it.
Personally, it's leagues better than smogon. As these rules are based on the official rules of the battle haxway written by the developers. None of those eyebrow-raising specific bans that smogon is doing.
-User Name Origin: http://www.youtube.com/watch?v=tO_5esMq2kE#t=56s "Japanese Wii U. American Wii U. The future is yours, Xenoblade U."