Gun
Sweeps across one or two strings with the thumb and index finger pinched together. Only one nail strikes the string(s) in each direction. If this is played across two strings then the lower string is bent to raise it to a matching pitch.
Kwok is the only source that mentions this and does not provide a character for it. It may be an outdated technique; pinching the fingers together adds rigidity to a performer’s natural fingernails. Playing with artificial nails on top of natural nails may also benefit from that pinch, but performers who use artificial nails on the pads of their finger likely won’t see much value in this, and the angle on the thumb’s artificial nail may complicate it.