Beautiful fly as always.

With the caveats that I haven't read the book and don't know which other thread to which you refer, I'd offer up that there are Variants and Variants.

My understanding is that a Variant is a wingless fly with oversized hackle, a la Art Flick's Variants. I've also seen the term variant combined with named patterns to suggest that the pattern is like the named pattern but with something slightly different, but not enough for a wholesale name change.