This method of tying off support lines, when done correctly, is extremely secure, can be undone with control under high load, and will not jam. It is appropriate in almost any typical suspension situation.

There are several ways of tying off a support line that look very similar to this, but are not as safe:

• NEVER do a half hitch around the whole bundle; there is nothing stopping the half hitch from rotating, undoing your wraps. This is why we split the bundle on the first half hitch -- to lock it from rotating.
• Pay attention that when you pull the bight through the bundle, you are actually making a half hitch around part of the bundle, not just putting a bight through at the bottom. By making a half-hitch, you create a stable intermediate (but unlocked) configuration to pass through when untying, which gives you a chance to safely get everything ready to go right before lowering.
• Be sure to lock the slipped half-hitch with a second non-slipped half hitch, so that it can't quick-release by accident in the course of your suspension. The only exception to this is when you're about to adjust that line again, are closely monitoring it, and it's not the line keeping the head off the ground.
• Avoid the temptation to lock the slipped hitch by just passing the end of your line through the bight; that configuration has the potential to jam -- what happens is that the bight can pull back through the bundle, getting your working end locked up inside the hitch/bundle and making the whole thing nigh-impossible to undo under load.

One of the things I like about this method is that it can easily be done at the bottom of the line, as well as at the ring: