[UNDEFINED] uh? Shift Alt Control Command Caps lock R-Shift R-Alt R-Control L-Shift L-Alt L-Control 0 1 2 3 4 5 6 7 8 9 a b c d e f g h i j k l m n o p q r s t u v w x y z ` - = backspace return enter tab / \ ; ' . , [ ] # esc insert delete home end pg-up pg-down crsr-left crsr-right crsr-up crsr-down num-lock Keypad / Keypad * Keypad - Keypad + Keypad . Keypad = Keypad 0 Keypad 1 Keypad 2 Keypad 3 Keypad 4 Keypad 5 Keypad 6 Keypad 7 Keypad 8 Keypad 9 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 print sc scroll lk pause space Joy 1 B1 Joy 1 B2 Joy 1 B3 Joy 1 B4 Joy 2 B1 Joy 2 B2 Joy 2 B3 Joy 2 B4 Joy 1 L Joy 1 R Joy 1 U Joy 1 D Joy 2 L Joy 2 R Joy 2 U Joy 2 D
This file is pretty self-explanatory. The biggest reason the player would want to edit this would be to translate the key names.
The very first key is named "[UNDEFINED]". This is the text that appears when a certain control has no key binded to it, because it was overwritten by another control.
The second line is a bit more mysterious. "uh?" would lead to indicate that the game didn't understand the pressed key, but if the player tries to assign a key that isn't on the list, the game will simply ignore the key press and resume asking for a key.