Pokémon Organized Play
From Bulbapedia, the community-driven Pokémon encyclopedia.
Pokémon Organized Play, often abbreviated as POP, is an official gathering of Pokémon Trading Card Game players to play games, trade, and just generally have fun and learn about the game. It is typically held once a week in a gaming store and organized by a League Leader. The League Leader awards special POP packs for good sportsmanship and good playing.
POP Packs
POP Packs are Pokémon TCG packs that only contain two cards, as opposed to the typical nine or ten. Although these packs almost always contain fairly worthless commons, once in a great while a player may pull a very good card, such as an Umbreon 
. These packs can typically only be found by participating in Pokémon Organized Play, but can occasionally be found for sale at stores which carry TCG packs.
