Pokémon.com has revealed information about the 2011-2012 Modified format, including the sets rotated out. The new format will include all sets from HeartGold & SoulSilver on, rotating out seven sets. Due to rule changes in the Black & White set, The Pokémon Company International is considering the implementation of this new format on July 1, 2011, earlier than the usual September 1; final decisions will be made in June.
Additionally, TPCi has sent an email to players in the United Kingdom to confirm the rules for their Nationals event on May 29. For this event, the Black & White set will not be usable, and rule changes will not be put into effect. Players were notified that the set and rule changes will be legal at Spring Battle Roads.