"Feather Tenon," anyone?

The other day I was surfing Wikipedia and came across this article on Mortise and tenon joinery.

I was surprised that there was no mention of “mortise and loose tenon.” In that article, the joint was labeled as a “feather tenon.” I’d never heard it called that. Being curious, I did a google search that resulted in only 50 results, 14 of which were displayed. Nearly all of them were exact copies of the original wikipedia article. A similar search for “loose tenon” results in thousands of hits.

My thought is that either:

a) “Feather tenon” is technically correct, copied from some textbook somewhere, but no longer (or rarely, or never) used.

b) “Feather tenon” is used outside the US or the “English-speaking world” and the English definition simply dominates the internet.

c) The definition is incorrect or written perhaps by someone who either misunderstood or is in a relatively isolated region of the world where “feather tenon” is the more common name.

(update) or d) I’m living in a cave?!?

Since I know there are members from a wide range of countries, continents and woodworking traditions in this community (did you know that the site owner isn’t American! – sorry, Martin, I couldn’t help myself! ;) ), surely if it’s in common use, someone here will know about it!

Can anyone set me straight?

-- Patrick, Chicago, IL www.TenonAndSpline.com