POP Series 4 was the second of the POP Series promotional sets to be available at the Pokémon TCG World Championships, with POP Series 2 previously being available in 2005. In order for players to obtain a booster pack from the set, they were required to challenge and beat the 15-and-over champion, Tsuguyoshi Yamato, from the previous championships. The set saw mainstream release in sanctioned tournaments in September, being available until March.
The rare cards Deoxys δ, Flygon and Mew have holographic versions and were available in Value Packs. In an unusual move, Mudkip, Pikachu, Wobbuffet (all common) and Combusken (uncommon) also have holographic versions.
The holographic Deoxys δ is also unique among holographic δ Delta Species cards, as it features the "cosmic" holographic design as opposed to the plain holographic treatment every other δ Delta Species card features.