We recently got a tag suggested that had the description
dnd-3.x is a tag used to denote a specific and standardized hybrid play style using both the 3.0 and 3.5 versions of dnd simultaneously.
Play style is defined by allowing all rules of both systems, except where a rule from 3.0 was replaced or updated by a rule in 3.5. Thus 3.5 material has dominance in all cases over 3.0, but anything that was not updated or replaced from 3.0 is still valid and usable in-game.
This seemed like a neologism for a practice rather than a game in its own right, and I rejected the tag edit. (Although “D&D 3.x” is a common shorthand to refer to both games, that did not seem to be what the tag was being suggested for — nor would we need a tag just for that shorthand.) The author reiterated that it is not their own invention and that it is a widely-played game in its own right.
Does this creature exist? Is there a specific, well-defined, and standardised game called “D&D 3.x”? And if so, is it widely-known and -played enough to transcend “we just use both game's books with this rule of thumb” and emergently become a singular, distinct game in its own right?
In other words, is this a distinct game and topic in its own right, such that we need/should support it as a distinct game with distinct tagging? Or is tagging questions about specific interactions with dnd-3ednd-3.5e the right way to categorise questions arising from this practice?