The usage of "alternate_costume" does not match its wiki

Wiki entry says "A character wearing a (typically fanmade/unofficial) costume other than the one they are typically depicted in. For a game character, this is a costume other than the standard one that can be unlocked within the game."

However in reality this tag is also being used to denote official alternate costumes...specifically skins...however by this wiki description you'd think that would be an improper usage....especially that second line "other than the standard one that can be unlocked within the game"...well skins can certainly be unlocked in the game.

So in my mind there are 2 options...update this wiki entry to include official alternate costumes...or a second option, and much much more work, create a new tag that denotes official alternate costumes (maybe just something like "official_alternate").

I think in an ideal world we'd do the latter but it would be a huge amount of work as the tag is at like...112k entries and this task would require a rather deep knowledge of certain characters...you'd have to know which costumes are in fact official and which are not.

The discussion about skins, craft essence, dark persona, in-game alternate colors... etc has sprung up a few times, generally fizzling out into "let's keep using the alternate_costume tag for now".
The wiki does mentions this aspect... though there is a small typo.
It should have been: "this is a costume other than the standard, one that can be unlocked within the game" The comma making the distinction that it's referring to other skins beside the standard one.

That being said, i was always for splitting the tags between original and official, skins and alternate costumes. Official being all the in-universe idol costumes from idolmaster, or that "1 dress":danbooru.donmai.us/posts/2680698 that Darkness wore for like 2 episodes, in-game skins etc.

For the name, i'd suggest keeping alternate_costume for official designs, since that's how the term is currently used in gaming/anime communities.
Then we'd create a new tag, like fan_costume, fan_made_costume, original_alternate_costume, etc. to cover the the other population of images.

BTW if we do this, i'm suspecting that after tag cleaning is done, way more than 112k images will be in the 2 tags. Since people on one side don't/didn't use alternate_costume for skins that much, and on the other, they didn't use it for fan-made contemporary takes on characters.
We might also get into another debate about what counts as an original_alternate_costume, for which i'm saying now that we exclude all underwear stuff, only costumes worn in a public setting.

If the distinction is between canon and non-canon (meaning appearing anywhere in official works or not), then i'd recommend the tags be official_costume / unofficial_costume. "fanmade" and "original" have their own connotations that would affect their usage.

on this topic, though, i've always felt it'd be more productive to have a tag for the inverse of the current alternate_costume. something like standard_costume, making it easy to subtract from a search if you want other looks. it's way easier to identify the typical character design than recognize which outfits are or aren't official in-game or whatever.