i think these pokemon should NOT be allowed:
Darkrai
Giratina
Lugia
Ho-oh
Shaymin/Skymin
Kyogre
Groudon
Arceus
Dialga
Palkia
any HACKED pokemon
Rayquaza
Regigigas
Heatran
Mew
Mewto
the one's that ARE allowed:
any of the 493 pokemon that I did NOT list there.