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== Incorrect Trivia ==
Out of all moves that have been HMs in all six generations, Fly is the only one that some Pokémon can learn by leveling up. (Though the move Waterfall also existed in all generations and some Pokémon can learn it via leveling up, it was not an HM until Generation II.)
This is incorrect, as Seel can learn Dive in generation 5 by levelup.