I thought WTF set the rules, and hence "standards" for sparring. As a result of that understanding, I don't disagree with someone who says they practice WTF-style TKD; the KKW-grading schools I have seen spar in WTF rules, and focus their training on that ruleset (e.g., little practice on knee kicks or head punches, since they are not allowed in tournaments).
So you define a style by a sparring ruleset and nothing more?
I guess I teach a whole bunch of styles then, since we spar under more than one ruleset.
A style of MA is a complete system; not just one small fragment.