The double overhand noose is a hitch knot used to bind a rope to a carabiner.

Releasing

A heavily tightened double overhand noose will jam. The binded object has to be removed before untying.

Usage

Cavers and Canyoneers might use the double overhand noose to bind a cow tail or a foot loop to a carabiner.

Security

As the double overhand knot, it neither slips nor turns around. However, a third round turn

Triple fisherman's knot

The triple fisherman's knot is a bend knot, used to join two ends of rope together. It is an extension of the double fisherman's knot and is recommended for tying slippery, stiff ultra high molecular weight polyethylene and aramid cored ropes....

might be useful with some highly lubricious spectra/nylon ropes.