AW: „ALT“ is an abbreviation for „Alternative“ and refers to a configurable function key, (see device manual under “Misc Setup” p.59) where a specific function can be assigned via the Setup menu. This unit features a ALT hard key on the front panel and a ALT button in the HMI. The following direct function assignments are possible, for the “ALT” button: CAM/Mute/NAVI/Tuner/EQ/Setup/BT-Music/BT/ DISP/iPod/USB/HDMI/GAA/DVD/AV-IN.