HelenOS sources

KC_NPLUS          112 uspace/drv/hid/adb-kbd/ctl.c 	[0x45] = KC_NPLUS,
KC_NPLUS          149 uspace/drv/hid/atkbd/atkbd.c 	[0x79] = KC_NPLUS,
KC_NPLUS          137 uspace/drv/hid/usbhid/kbd/conv.c 	[0x57] = KC_NPLUS,
KC_NPLUS          142 uspace/drv/hid/xtkbd/xtkbd.c 	[0x4e] = KC_NPLUS,
KC_NPLUS          223 uspace/srv/hid/input/ctl/sun.c 	[0x7d] = KC_NPLUS,
KC_NPLUS          179 uspace/srv/hid/input/layout/ar.c 	[KC_NPLUS] = '+',
KC_NPLUS          208 uspace/srv/hid/input/layout/cz.c 	[KC_NPLUS] = '+',
KC_NPLUS          187 uspace/srv/hid/input/layout/fr_azerty.c 	[KC_NPLUS] = '+',
KC_NPLUS          188 uspace/srv/hid/input/layout/us_dvorak.c 	[KC_NPLUS] = '+',
KC_NPLUS          182 uspace/srv/hid/input/layout/us_qwerty.c 	[KC_NPLUS] = '+',
HelenOS homepage, sources at GitHub