Crossing knots
Knots are rarely encountered in the middle of a rope pitch, but on occasion a knot may need to be tied to join two ropes together, or a butterfly knot may be used to isolate a cut or wear spot in the rope. In both of these examples a mid-rope knot should be a temporary solution to these problems, and the rope should be replaced as soon as practical. Knowing how to safely cross a knot during ascent or descent should be a core vertical skill that is practiced for when these situations are encountered. Two points of contact should always be maintained while ascending, and descenders should always undergo a safety check whenever the are removed and reinstalled onto the rope.