Page 133 - Peter Randall "The Craft of the Knot.."

Snare, this knot is a very good general-purpose noose to learn.

STEP 1 Tie a Double Overhand Knot (see Chapter 1) with the running
end over the standing part.

STEP 2 Tighten as shown.

Because the Double Overhand Knot can hold tension when tightened

down, the loop opening will not close down until it is pulled on, which
helps to explain its nefarious past with poachers. Knots that make use of
the Double Overhand structure remain very useful today due to their
high security even when tied with slippery synthetic cordage. The Triple
Overhand version of this knot is even more secure.

GUY LINE HITCH

A “guy line” is a rope or wire used to hold a pole, antenna mast, or tent
in place. There is generally more than one guy line, and when the Guy
Line Hitch is used, the length and tension of each can quickly be
adjusted.