The Race Director may declare a Full Course Yellow period if he decides that this is necessary for safety reasons. Once under FCY, cars will slow down to 80 kph, in single file, and maintain their distance to the car in front and the car behind. Overtaking is strictly prohibited under the FCY. Once the message is displayed on the monitors, all cars must immediately slow down. The pit lane entry and exit remain open and cars are free to pit.
Once the problem(s) is/are solved, the Race Director will return the track to green; this is done by posting a message on the monitors. At this stage, all marshal posts will replace the yellow flags and FCY boards with waved green flags. Racing and overtaking will normally resume. An FCY period may be followed by a Safety Car intervention if the problem remains unsolved and safety may be at risk.