To my eye, it looks much more like a minor variation on the so-called Ashley Bend. I’ve attached an image so others know what you’re referring to. Reading a little further in the Ashley Book of Knots we find something of interest:
1408: Here is another bend with the same untrustworthy features as the “Whatnot”, yet in the form shown here it ranks among the securest of bends known.
1409: But in this second form it is one of the least secure knots known, its only rival being the Whatnot. The change from one of its forms to the other may occur accidentally or intentionally. So the knot is quite untrustworthy.
Tying this in more elastic material, you get a dramatic demonstration of what Ashley is talking about. It rolls apart. (Update: I also had such a single-pull rollout experience in some twisted polypropylene loaded only by hand. The rolling action destroyed the twist of part of the rope.)
So it becomes quickly evident why 1408 and its shifted form in 1409 are neglected.
This has implications for the Ashley Bend that I did not consider before. It is a very easy error to mistie the Ashley Bend and get the scary 1408/1409! They even look like the Ashley Bend. For 1408/1409, the “q” initially goes through the “b” from above. For the Ashley Bend, the “q” initially goes through the “b” from below.
Poor Ashley; getting his name tacked to a bend in a way he might not appreciate, especially considering this relationship.
cf:
http://notableknotindex.webs.com/butterflybend.html
http://igkt.net/sm/index.php?topic=1892.0
