The shoelace knot is a doubly slipped reef knot formed by joining the ends of whatever is being tied with a half hitch, folding each of the exposed ends into a loop (bight) and joining the loops with a second half hitch.
The size of the loops and the length of the exposed ends are adjusted when the knot is tied.
A variation of the procedure involves looping the top part of the knot twice instead of once, resulting in a finished bow of almost identical appearance but with the laces wrapped twice around the middle.
This Double Slip Knot holds the shoelaces more securely tied while still allowing them to be untied with a (slightly firmer) pull on the loose end(s).
Just as it is possible to stack a number of half hitches to create a longer knot – remembering the reverse direction each time – which is equivalent to tying one reef knot on top of another, so bows which need to reduce long lengths, such as corset tapes, can be tied on top of each other, slipping every other layer.