Some questions on internal key definitions/flags

While we’re at it, what are these useful for:

#define KEY_BACKLIGHT_DOWN 0xF1
#define KEY_BACKLIGHT_UP 0xF2
#define Key_BacklightDown (Key) { KEY_BACKLIGHT_DOWN,  KEY_FLAGS }
#define Key_BacklightUp (Key) { KEY_BACKLIGHT_UP,  KEY_FLAGS }
#define KEY_RIGHT_FN2 0xfe
#define Key_RFN2 (Key) { KEY_RIGHT_FN2,  KEY_FLAGS }
#define KEY_LEFT_FN2 0xff
#define Key_LFN2 (Key) { KEY_LEFT_FN2,  KEY_FLAGS }

I had previously asked this about the backlight keys but a further clarification:

do they refer to the screen backlight or the keyboard backlight?