Happy New Year!
I had some correspondence with Dan Lehmann in 2004 about this knot and he was very helpful. He found one "accidental" appearance in one edition of a book, where it was drawn by mistake, it appears not to have been published. I thought I'd have a go at putting it here to see if anyone around the world can identify it or has used it.
TYPE OF KNOT - Adjustable hitch for tent guylines etc.
DESCRIPTION - This is effectively a double Clove Hitch (?) over the standing part forming a sliding knot which holds firm when stress is applied to the loop and standing part. It works very much like the various versions of the Taut-line Hitch.
METHOD OF TYING
1. Tie a loose overhand knot with the leading end on top and facing right - Step 1
2. Place the leading end over itself and the standing part - Step 2
3. Loop the leading end round twice - Step 3
4. Pass the leading end through the two loops - Step 4
5. Work the knot neatly together - Step 5
See attached images. It would only allow me to attach 4, but I can provide more!
I look forward to any comments or information.
Brian