Gates:Unused downloadable content
Unused downloadable content for 
Pokémon Mystery Dungeon: Gates to Infinity that was never meant to be seen by the public was leaked thanks to a security issue involving Nintendo's servers that allowed all DLCs to be downloaded if the key for one of them was known. The full DLC contains 102 NCCH partitions, even though only a few of them were intended to be obtained by players. The unused DLCs contain placeholder Unused Dungeons and three unused music tracks, which are remade versions of tracks from 
Pokémon Mystery Dungeon: Explorers of Sky: Craggy Coast, Star Cave and Vast Ice Mountain Peak. Most unused DLC entries are assigned an unused red Magnagate icon.
Items that can only be found in DLC dungeons can still be used if the DLC is uninstalled or the SD card is removed. They will display as a question mark with the name "Mysterious Item". Despite this, all of the real names for the items can be found in the files of the base game.
Additionally, the names of all the released DLC-exclusive dungeons are present in the files of the base game.
See Also
References
- [1] DLC explanation on 3DBrew