Armenian Edging Stitch
An attractive knotted edging is worked left to right. Bring the thread through from behind the fabric edge. Move the needle to the right and insert the needle through the fabric from the back. Leave the thread loose and twist it into a a loop, placing the needle through the middle. Tug the knot to secure it before moving on to the next stitch. Most effective when worked with a heavy thread.
Mary Thomas's Dictionary of Embroidery Stitches, p 2