Yarn over

The term "yarn-over" refers only to the act of wrapping the yarn around the needle, and not to the working of the next existing stitch.

Yarn-overs are also common in eyelet and lace knitting, since they produce stable holes in the fabric.

Yarn-overs are also used to slip stitches neatly without having to pass the yarn in front or back.

Thus, the yarn is "tucked away" by passing over the slipped stitch, rather than in front or back.

Wrapping the yarn multiple times produces a very long loop, which can yield interesting visual effects.