A part of the hand. GURPS Martial Arts page 115 mentions under Worrying:
- Twice the amount to cripple a hand removes a finger (see
Missing Digit, p. B144).
It is also used to deliver other techniques in Martial Arts:
- Eye-Pluck ("using the clawed fingers of one hand to grab an enemy’s eye")
- Eye-Poke ("a jab to the eye using an extended finger")
- Lethal Eye-Poke ("attempt to drive an extended finger through an eye")
Per Kromm in 2013 http://forums.sjgames.com/showpost.php?p=1600459&postcount=23
- It's probably -11 or worse to target the top pinky joint