The ordinary shoelace knot is the 'slippery square knot'. It's 'slippery' because its tied with a loop so you can pull the free end to release. And it's 'square' because its symmetrical when tied right.
There are three ways to tie a square knot wrong. One of them is the 'Granny'. I don't remember the names of the others.
Anyway its the reason our climbing staff teach to never tie any climbing rope with a square knot - because you have three ways to kill yourself. Tied wrong it can just 'walk off the rope'.
I have a knot book that refers to these types of knots as "exploding" knots. They are essentially the same as the original knot, but the final tuck is done with a bight to make untying it easily.
There are three ways to tie a square knot wrong. One of them is the 'Granny'. I don't remember the names of the others.
Anyway its the reason our climbing staff teach to never tie any climbing rope with a square knot - because you have three ways to kill yourself. Tied wrong it can just 'walk off the rope'.