This stitch is just an Outline Stitch and a Stem Stitch worked next to each other. The effect is that of a fine Chain Stitch worked from left to right. When worked on pleats, this stitch creates a horizontal line about the same thickness as a Cable Stitch line, but does not bunch up the pleats in pairs.

Of course, the Stem Stitch can be worked above the Outline Stitch, which will make the "chain" go from right to left.