A span loop is a non-jamming loop that can be tied away from the ends of the rope.
The span loop is known for being extremely easy to untie. The beginning of tying this knot begins with tying a Half Sheepshank, which is also known as a Bell Ringer's Knot. In order to tie this, a one handed twist method is recommended for making a bowline. One bight or loop will poke up through the half-hitch, and it will perfectly match the end of the rope that is also poking up through the signature half-hitch part of a bowline as it is done with the one hand twist method. The next thing to do is to push the bottom loop back up and through the top loop. 
- ↑ "Span Loop". Notable Knot Index. Retrieved 12 January 2013.