Markings on dipstick:
WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, and 2003 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
a - Do not top up oil.
b - Oil can be topped up. Oil level may then rise as far as area - a -.
c - Oil must be topped up. After topping up, it is sufficient for oil level to be somewhere in area - b - (grooved area).
NOTE:
- Oil level must not be above mark - a - on dipstick.