Pokémon Tower Pokédex glitch

A relatively minor glitch exists within the Generation I Pokémon games. Usually the Pokédex should register Pokémon that the player has seen however, when the player encounters a ghost in the Pokémon Tower if the player does not have the Silph Scope, according to the game the relevant Pokémon cannot be identified. Regardless of this, the Pokédex still registers the Pokémon which was the ghost as seen.