"I don't see any description of a Zeppelin Double Loop there."
Right. There is no description THERE; however, the operative sentence in my post is this, which occurs at some point after the link:
"Just wrap around your post twice and make the knot itself in the same fashion as in the above instructions."
The point of making the structure in that manner is to accomplish two things:
(1) To make a double Zeppelin Loop without bulking up the Zeppelin Knot too much
(2) To make a double Zeppelin Loop quickly and easily, merely by extending what has already been learned
Thinking in terms of item (2) above--at least some of the time--can be very useful; yes, of course, there are times when it would be unwise to think in those terms.
I tried knot4u's Double Zeppelin Bend. I like it. However, the Zeppelin Bend's type of symmetry is such that there is little room for improvement. This situation makes the Double Zeppelin Bend . . . a very pretty knot.
Contrast the beauty of the above knot with the ugly monstrosity that my loop-doubling method turned the Zeppelin Knot into. But, the method works, and works well and consistently, once you figure out how to dress the beast.
I tried roo's Double-Wide (by making a double-coil b and a double-coil q). Now THAT'S one wide beast.
Then whaddaya think I did? I made a Double-Wide Double Zeppelin Bend. It was BIG. REAL big. But it was NOT easy to untie! It JAMMED!
If I got it right, Dan_Lehman's extra half turn on the b and extra half turn on the q resulted in something quite interesting, which was easy enough to untie.
JCS