A Knifehand Side Strike (sonnal yop chigi) is a strike made with the knifehand outward to the side of the body. The strike begins on the opposite side of the body, with the palm facing the body. The knifehand then rotates to palm-down on contact with the target.
The Knifehand Side Strike appears, for instance, in the forms Hwa-Rang and Hansoo.