Hoe komt het dat bij Pokémon Leaf Green ik de Pokémon niet kan renamen?

Ik heb gezocht en ik heb dit gevonden:
'Renamable Pokémon

If the Pokémon was caught by the player that currently owns it, he will say that the name could be better and offer the player the option of changing it.
If the Pokémon he's judging is an outsider Pokémon (if it was originally obtained in a different game, via an event, or via an in-game trade), he will say that the name is perfect and refuse to change it. The Name Rater in Orre will also refuse to rename a Shadow Pokémon until it has been purified.
However, if both players have identical Trainer IDs and secret IDs (which is extremely unlikely), he will allow name changes. In Generation V, both players must also have the same name and gender as well.
Additionally, in Generation I only, should the player press End with no characters in the nickname space, the process will proceed as if the player canceled the nicknaming process, whereas in later games it will be treated as giving the Pokémon the same nickname as before.'

Het lijkt er dus op dat die Pokémon die je wilt renamen via een in-game trade is verkregen.