In the Pokémon Trading Card Game, there are often cases where a Pokémon card has an attack which has the name of a move it cannot learn legally in any of the games. It is unknown whether these instances are actual mistakes, or if card templating does not have to strictly follow game learnsets.
Occasionally, in-game event Pokémon that can be transferred onto the main series games have a move that is not normally included in that Pokémon's moveset (a prime example being Pokémon Box Ruby & Sapphire, which gave away four separate Pokémon with moves that were not normally available to that specific Pokémon).