The following flags are used by motorsport track marshals and other officials to signal the drivers. The start and end of races weare traditionally signalled by the wave of a flag. The starting flag was often the national flag of the country in which the race was held.
Caution, danger ahead (yellow)
Oil on track (red and yellow vertical stripes, 5 red, 4 yellow)
Let faster driver overtake (Blue)
Ambulance or other official vehicle on track (white)
Finish - the 'checkered flag' (black and white checks, 6x9)