HelenOS sources

KC_F6             140 uspace/drv/hid/adb-kbd/ctl.c 	[0x61] = KC_F6,
KC_F6             132 uspace/drv/hid/atkbd/atkbd.c 	[0x0b] = KC_F6,
KC_F6             111 uspace/drv/hid/usbhid/kbd/conv.c 	[0x3f] = KC_F6,
KC_F6             124 uspace/drv/hid/xtkbd/xtkbd.c 	[0x40] = KC_F6,
KC_F6             707 uspace/lib/vt/src/vt100.c 		vt100_key(vt, 0, KC_F6, 0);
KC_F6             207 uspace/srv/hid/input/ctl/stty.c 	0,	KC_F6,		0x1b, 0x5b, 0x31, 0x37, 0x7e, GSP_END,
KC_F6             112 uspace/srv/hid/input/ctl/sun.c 	[0x0e] = KC_F6,
HelenOS homepage, sources at GitHub