A - Main key
This key fits all vehicle locks. The main key has a backlight. To turn on the backlight, press the round button in the middle and hold it. For the backlight to work properly, the battery in the key must be in good condition.
B - Additional key
This key is only used for the doors, fuel filler flap lock and tailgate of the Avant model.
C — Master Key Code Identifier
The identifier contains the code of the main key for making a duplicate if the original is lost. The identifier must be stored separately, in a safe place.
(The original article is available on the website «AUDImanual»)