This article is incomplete. Please feel free to edit this article to add missing information and complete it. Reason: Does Card Pop! work between different languages? (including between the English-Spanish-Italian and the English-German-French cartridges) How many player IDs can be held before some are overwritten? If the Japanese version of the first game is being played on the original Game Boy or the Game Boy Advance, is Card Pop! usable? (since the Game Boy Color infrared port is not required) Does the second game (which is Japanese only) have built-in infrared or does it use the GBC infrared? Are all cards available via Card Pop! or only some cards? (which cards exactly are available?).
When two games are connected via infrared, each player will receive a random card. A player cannot Card Pop! with the same partner save file again until both players have used the feature with so many others that their partner's ID is overwritten in both save files. If the save file is deleted, all Card Pop! data is deleted, so whether a new save file can Card Pop! with another game's save file is unaffected by the players the previous save file performed Card Pop! with.
Card Pop! cannot be performed between Pokémon Trading Card Game and Pokémon Card GB2: Here Comes Team GR!. Attempting to do so can result in glitches such as a game freeze or a loss of save data in Pokémon Trading Card Game.