This move is contained in a TM. This TM is not obtainable in-game, thus this move is only obtainable with use of cheating devices. No Pokémon can learn this move, so the TM is useless. Additionally, the machine was not included in the game code for Explorers of Time, Darkness, and Sky. The move still remains functional, but its name (except in Japanese) and description are dummied out as "$$$".
This move is likely to have been replaced by the HMRock Smash, which has the same purpose as Excavate in these games.
In all non-Japanese versions of Red and Blue Rescue Team, the move's description is "NULL", while the TM's description is partially translated in French and German, left blank in Italian, and fully translated in Spanish.
In French, German, Italian, and Spanish translations of Red and Blue Rescue Team, the move's name is left blank and the TM's name is "NULL". In the TM's description, its name is left untranslated in French and German, while it is translated in Spanish as Excavar, sharing its name with Dig.