What does this gauge mean?

[DeeTurbo]

Oil gauge*
When the ignition is switched on, this
indicates the oil level:
The reading is only valid if the vehicle
is on level ground and the engine has
been switched off for 10 minutes.
- needle in zone C, the oil level is
correct,
- needle in zone D, check the oil level
using the dipstick and top up if necessary.
Never exceed the maximum level on
the dipstick.
The oil level indicator switches off
approximately 15 seconds after starting the engine.