In a few articles, I see there is a tag of 'variations' on them.
There are 2 possible meanings that I can see for this tag:
'Variations' currently does not have a definition, so it's currently being used for both cases above.
My question would be, which definition should 'variations' be? perhaps a new tag for chess variations be created? i.e. 'variants' or 'chess-variants'?
Using a variations tag to mean 'variations of a particular opening, middlegame, or endgame position' seems to add little additional information to the question. Like a tag of 'code' on stack overflow. Don't think we need such a generic tag, though something like 'calculation' or 'analysis' is appropriate if that's what the question is about.
Having a variants or chess-variants tag makes a lot of sense though, along with tags for specific chess variants like bughouse, atomic, etc. like you said.
To expand on Bort's answer:
As of this writing, there are 3 questions tagged variations. On all of them, the variations tag could (and probably should) be replaced with opening without really losing any meaning.
There was one question referring to chess variants (specifically mentioned Chess 960). I retagged that as chess-variants just so that it is separate from the variations questions. Daniel δ had written a fairly exhaustive tag-wiki for variations, but the information was referring to chess-variants. I moved the tag-wiki to the correct tag and embellished some as well.
Feel free to re-tag or suggest better wording for anything as well.
