The subject of this article has no official name. The name currently in use is a fan designator; see below for more information.
An in-game trade is a trade made with NPCs in the core series and spin-offPokémon games. The process uses the same trading sequence as player trades and is usually done for Pokémon that are difficult or impossible to obtain through other means, or for Pokémon unavailable at that point of the game. In later games, the traded Pokémon often has special moves, like Egg Moves.
This article is incomplete. Please feel free to edit this article to add missing information and complete it. Reason: Check that the Gen II held items of trade evolutions and Japanese Blue's Krabby are correct.
All Trainer ID numbers and IVs are random in the Generation I games. The Original Trainer always uses the hardcoded text string 0x5D, which is displayed as TRAINER (Japanese: トレーナーTrainer) in the game's language. In Western language versions of the handheld games and Pokémon Stadium, this string is displayed in ALLCAPS ("TRAINER" in English), whereas in Pokémon Stadium 2 it is displayed in title case ("Trainer" in English).
The held item column refers to the item the Pokémon will be holding if it is traded to a Generation II game. With the exception of Pokémon that evolve during that trade and Krabby in Japanese Blue, they have the same item a wild Pokémon of the same species would have if it were traded to a Generation II game; Pokémon that evolve during the trade have the item their evolved form would have, while Krabby has TM13 (Snore) instead of TM33 (Ice Punch).
This (full) data is stored in Mobile System GB related code for Japanese Pokémon Crystal. It also appears earlier in the ROM, but with the Original Trainer data not included. Kabīn is possibly a reference to the Game Freak Kōji Nishino and Snorlax (Japanese: カビゴン) in-jokes, and the early 'Kabīn battle' concept art. The code remains in English Crystal, however, the Japanese names were not translated; resulting in garbage text, and the game causes problems as it expects the English name length.
In the English language version of Pokémon Diamond and Pearl, Kazza, Charap, and Gaspar are functionally Japanese in origin. While this has no effect in the Generation IV games (since their species do not have foreign Pokédex entries in the Generation IV games), it becomes noticeable when sent to later generations. These Pokémon have the correct language of origin if obtained in any other game language or Pokémon Platinum.
Similarly, the old man who trades the player Jynx for Poliwhirl in Cerulean City claims that Poliwhirl "went and evolved". Poliwhirl does not evolve by trade in the Generation I games but rather through the use of a Water Stone. In the context of the Japanese Pokémon Blue, the old man trades away Haunter for Machoke, both of which evolve by trade.