The left twist stitch is a mock cable. By knitting stitches out of order, a twist can be created in the fabric. It's more efficient than a 1/1 Cable Left or Cable 2 Forward and can be used in place of those stitches.
The Faux Cable Edging is a delicate mock cable rib. Using slipped stitches and eyelets, it is a simple stitch with a lot of visual payoff. With it's vintage look, it would work well at the hem and cuffs of a cardigan or on babywear.