This bind off creates a decorative edge. It requires at least one knit stitch prior to starting. Basically we are knitting into the front, then back, then front again of the stitch on the left hand needle, but binding off as we go.
Directions K1 but don’t remove original stitch from left hand needle. The new stitch has passed to right hand needle as normal. Pass the previous stitch over this new stitch. Knit into the back of the stitch on the left hand needle, keep the original stitch on left hand needle and pass the new stitch to right hand needle as usual. Pass the previous stitch over last stitch worked Knit into the front of the stitch on left hand needle (as normal) Pass the previous stitch over last stitch worked.