I was informed without shoulders ( the reason I questioned what to call it) that both
dovetail and mortise-tenon joints have shoulders so "set neck" is what it is.
Since I tapered it...."tapered set neck" is accurate and fitting.
I did consider making it straight but it thought it would be easier to continue with the
taper.
I need to do a build with a straight set-in to determine which is best for me.