I understand it can be broken down into a thrusting side kick next to the target which then converts the thrusting motion into a sweep through the target with the back of the heel or the foot sole.
Works to sweep the opponents feet out from under them, or through the ankle, calf, knee, thigh, kidney, ribs, solar plexus, guard (to expose a target, with a view to connecting shortly after with another kick from the same foot), neck, jawline, back of the head or temple.
The kick demands great hip strength to be used with any real oomph and has to be trained constantly to keep the weapon sharp.
To me it is more of a sport kick, but it has some devious and wicked applications if one is so inclined.