http://www.smogon.com/forums/threads/tournament-rules-and-general-guidelines.3486049/
Battle Spot Singles!
Battle Rules:
Level 50
3v3 Singles (Bring 6, choose 3 to participate)
Best of 3, you may change your team of 6 between matches
Banned Pokemon: Mewtwo, Mew, Ho-oh, Lugia, Celebi, Kyogre...