Unobtainable items are items that exist within the game’s code, but cannot ever be obtained by players via normal gameplay. These items are usually found by extracting information via the game’s cache. Some items are found in game, or within certain interfaces, but cannot be placed into the inventory.
These items, like all other items, have an ID number assigned to it.
Item IDs may change over certain updates, and may fill unused IDs that are considered null. Certain items used exclusively may be removed from the game and their item IDs relabeled as “Null”, which are represented in the cache as pink skirts.