赤緑の有志英語版で生まれたMN記号が本編赤青に引き継がれたらしい件
OriginalMN.png @ Bulbagarden Archives
ポケモン本編アメリカ上陸前、赤緑の有志英訳が勝手につくられはじめる
Pocketを3文字長、Monsterを省略形MNで1文字長、間のスペースと合わせて5文字長の特殊文字にする
米国任天堂スタッフ陣がこれを妙案と捉え、本家赤青でPK1文字、MN1文字が採用される
ノブ・オガサワラ先生は後年これを「中華圏のハックから拝借」と回顧した:
Nob: That "PKMN" notation, that was stolen from some hacked Chinese ROM of RB. / They were examining the ROM, saw it, decided that's a good idea and adopted it. (2020-05-19)
実際に中華圏で有志英訳が生み出されたのか、ノブ先生の記憶違いか、真相は不明
1997-07-01香港返還は関係あるか?
https://bulbapedia.bulbagarden.net/wiki/ROM_hack#Trivia
The MN character introduced in the English release of Pokémon Red and Blue can be traced back to a partial fan translation patch of the Japanese Pokémon Blue from December 1997 and January 1998 that predates Nintendo of America's announcement of the game in the United States. This has been confirmed by Nob Ogasawara on Twitter, although he misremembered it as a bootleg.