Bowline on a bight advocate the use of a figure eight twisted version of the Bowline on a bight. This knot can be used to provide a toe hold in the middle of a rope; to make an emergency bosun's chair; and to create an upper rope "block" to make a crude purchase by threading the rope round an anchor point and then back up through the loop. It is sometimes used in sport climbing to tie into two anchor bolts independently. This knot is convenient when a dependable loop is required but neither end of the line is available. It's also commonly used
The 85 Ways to Tie a Tie described in the book, in order of size, are as follows. Terminal sequences (the final three moves that end in the tying of the knot) are in bold. The knots are sometimes designated by their number alone (e.g., FM2 for the four-in-hand, with "FM" standing for Fink-Mao). A knot is self-releasing if, when the thin end is pulled out through the knot, no knot is left; as all knots start on the left, a knot is self-releasing if the terminal sequence is Ro Li Co; it is "not" self-releasing if the terminal sequence is Lo Ri Co. Symmetry and self-releasing