The Fame Checker has a simple design. It is dark red and has a screen roughly the size of the Pokédex screen. It has four black circular buttons on the left side, and on the right side it has a Poké Ball-shaped button or wheel split into three different portions.
Each character who appears in the Fame Checker has six different entries that can be unlocked. Each of these entries corresponds to a quote about the character that the player can encounter within the game. When the player encounters this dialogue in the game, it will be registered in their Fame Checker. Each entry has a title (e.g. "Favorite kind of Pokémon", "Friends and Family", etc.), a location (which does not necessarily correspond to the save location), and the character or text being quoted; additionally, the overworld sprite of the character or object that provided the quote appears as an icon that represents that entry. Prior to unlocking an entry, it appears as a question mark with no title or indication of where the player can unlock it.
These quotes can come from a variety of sources: the character themselves, major characters, unnamed NPCs, NPC Trainers, signs, Pokémon Journal, etc.
Once all six data pieces are obtained in a person's section, the player can read a message that that character has sent directly to the player.
The characters who have information stored in the Fame Checker in Generation III are as follows:
In Going Green, it was revealed that Professor Oak had been forced to make the aforementioned voice messages by Orm as a part of Team Rocket's plan to have Professor Oak reverse-engineer Team Rocket their own version of the Pokédex in preparation of catchingDeoxys. However, what Orm hadn't noticed was that Professor Oak had secretly turned Green's Fame Checker on while being attacked, recording the conversation between him and Orm into it.
Trivia
In Koga's Fame Checker entries, his daughter Janine is incorrectly identified as "Charine".