Among the NPC Pokémon trades in the game's data are three trades not assigned to any NPC, and thus inaccessible. One of them, a Beedrill in exchange for a Butterfree, exists in the data of every first-generation title. The nickname of the Beedrill even changed from version to version, but the trade remained unused.

Pokémon Yellow replaced two functioning trades with unused ones. One requests a Pidgeot for a Pidgeot, and the other is a Mew for a Mew. In Japan, both are nicknamed Matsumiya, presumably after Toshinobu Matsumiya, who was in charge of Yellow's scenario. In the English version, the Pidgeot is named MARTY and the Mew is named BART.