!
Error prevention and placeholders in the Pokémon games:
?????????? | ????? | ! | Abnormal Pokémon | Bad Egg | Enigma Berry (Generation III) | Error! | Error codes (Generations I and II) | Error traps for damaged save data | Error traps to prevent impossible progress | Event data debugging messages | Instant victory effect (Generation II) | Mystery Zone | N/A | Pokégear instruction booklet trap | Rhydon trap | Special (location) | This Game Pak is designed only for use on the Game Boy Color. | This Pokémon cannot be traded.
?????????? | ????? | ! | Abnormal Pokémon | Bad Egg | Enigma Berry (Generation III) | Error! | Error codes (Generations I and II) | Error traps for damaged save data | Error traps to prevent impossible progress | Event data debugging messages | Instant victory effect (Generation II) | Mystery Zone | N/A | Pokégear instruction booklet trap | Rhydon trap | Special (location) | This Game Pak is designed only for use on the Game Boy Color. | This Pokémon cannot be traded.
This article is about the error trap for when a player attempts to speak to a character with no dialog defined to them in the Generation I Pokémon games. For instances when the game may display only "!" in the Generation IV Pokémon games see Spacing syntax glitch.
"!" refers to a placeholder term for when the player attempts to speak with a character with no dialog assigned to them on Pokémon Red, Pokémon Green, Pokémon Blue and Pokémon Yellow. Its purpose is unconfirmed, however it presumably acts as an error handler to prevent the game from crashing otherwise.