- Fan Nickname:
- Abomasnow is sometimes called Obamasnow due to similar sounding names.
- The Rotom formes all have their own names pertaining to their appliances: Rotom-H for Heat Rotom, Rotom-W for Wash Rotom, Rotom-F for Frost Rotom, Rotom-S (the "S" is for Slash, because the move it gets is Air Slash) for Fan Rotom, and finally Rotom-C (for Cut) for Mow Rotom.
- Mow Rotom also gets called "Mowtom" occasionally.
- "Eruptran" is used to refer to the special Heatran that came with the move Eruption, which it cannot otherwise learn.
- Giratina's formes are known as Giratina-A for the "normal" forme that first appears in Diamond and Pearl and Giratina-O for the Origin Forme that debuts in Platinum.
- Shaymin's Sky Forme is called Skymin or Shaymin-S.
- An Arceus not holding any of the Elemental Plates (thus making it Normal-type) and using the move Extreme Speed (usually with Swords Dance) is known as "Extreme Killer" or "E-Killer" Arceus. The name comes from how powerful STAB-boosted Extreme Speed is coming of of Arceus' high Attack stat, especially if it's boosted. Some Arceus formes as get names that are portmanteaus of their type + Arceus, such as Eleceus, Darkceus, Grasseus, and Ghostceus.
- Name's the Same: Pokemon Diamond is not to be confused with a bootleg version of Telefang.
- The Legendary Starfy introduces another character named Starly, this one being a starfish.
- This isn't the first 2006 Nintendo RPG to feature a player character named Lucas.
- An incredibly minor example: an NPC in the Lost Tower is a Roughneck named Kirby and uses Cleffa, a pink spherical Pokémon that is associated with stars. Why does that sound so familiar?note
- Official Fan-Submitted Content: Draco Meteor got its name from a fan contest held by the magazine CoroCoro.
- Refitted for Sequel:
- A Mr. Mime pre-evolution and evolutions for Lickitung, Tangela, and a Grass-type Eeveelution existed way back in Pocket Monsters 2 (the early incarnation of Pokémon Gold and Silver), before they were cut from the final product. These games, however, revive them as Mime Jr., Lickilicky, Tangrowth, and Leafeon.
- Canalave and Snowpoint City were both intended for Pocket Monsters 2 (as places known as New Type and North/Blue Forest respectively) but were cut. They're brought back here, slightly modified. As a nod to this, the Canalave City music is a remix of the Gen II credits music.
- Shellos and Gastrodon had been designed for Ruby and Sapphire, but due to time constraints, weren't used in those games. They were used here.
- Urban Legend of Zelda: Rumors persisted prior to the games' release that the starters would follow a new elemental dynamic (Fighting/Dark/Psychic instead of Grass/Fire/Water). Come Gen VI, where they actually do.note
- What Could Have Been:
- Spiritomb was originally going to be called Phantomb.
- Buildings were supposed to use the same 3D perspective (complete with 3D props such as tables) as the overworld instead of the forced 2D perspective.
Trivia / Pokémon Diamond and Pearl