the Bowline
The Bowline Knot is one of the most used loop knots. This variant is most used in the world. Probably due to its simplicity, security, and its relationship with the Sheet bend.
Keep the cross point in step A between a finger and thumb and make a clock-wise turn with your wrist. Without the loop in between, it is the same knot. If the loop is expected to be heavily loaded, the bowline is, in fact, not secure enough. There is a rule of thumb which states that the loose end should be as long as 12 times the circumference for the sake of safety.
This video demonstrates the bowline including a few ways of securing it:
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