Square Knot Single Column
When a rigger says just “Single Column” and not something like “Lark’s Head Single Column”, this is probably what he or she is talking about. This is a very intuitive and very fast method of tying a forward-tension Single Column, using a variation on a simple Square Knot. This version is commonly used in classical Shibari.
While this is good for many common uses, it suffers from the weakness of all Square Knots: it can capsize. So if there is going to be tension on the tail, be certain to add an additional overhand knot at the end to protect the knot. I explain more and show why below.