Marshals stationed at various points around the circuit use a number of standard flags to communicate vital messages to the drivers. These are the messages the flags convey:

Indicates that the session has ended. For practice and qualifying sessions, it is waved at the allotted time. During the race it is shown first to the winner and then to every car that crosses the line behind him.

Indicates danger ahead - such as a car that has broken down. A single wave warns drivers to slow down, while two waves mean that drivers must slow down and be prepared to stop if necessary. Overtaking is prohibited.

Indicates All Clear. The driver has passed the potentially dangerous point and the prohibitions imposed by yellow flags have been lifted.

Indicates that the session has been stopped, (could be due to an accident or poor track conditions).

Signals to a driver that he is about to be lapped and he should let the faster car overtake. If the driver passes three blue flags without complying he can be penalised.

Signals to drivers that a slippery track surface (due to oil or water) is ahead.

This flag is accompanied by a car number. It warns a driver that his car has a mechanical problem and he must return to his pit.

This flag is accompanied by a car number and it warns of unsporting behaviour. This flag may be followed by a black flag if the driver ignores the warning.

This flag is accompanied by a car number. It signals a driver to return to his pit and is usually used to signal to the driver that he has been excluded from the race.

This is used to warn drivers of a slow moving vehicle on the track.