The most common knot for attaching a harness to a rope is the figure-eight follow through, characteristically backed up by a stopper knot. Although it is harder to untie after a fall than some alternatives, it is inherently more secure, easier to tie, and easier to verify that it has been tied correctly. There are many variations of the bowline knot, including a variation of the double bowline, and some will untie themselves when repeatedly stressed and unstressed, as is common in climbing.
