From time to time Race Control need to communicate directly with a driver or drivers. And the only way to do this is via flag signals. It's important that everyone knows exactly what each flag means, so the messages that are passed aren't misunderstood or ignored.
Below is a short refresher on what each flag means. This information can also be found in the iRace Series Rules & Regulations.
Black Flag
Driver Action:
Enter the pitlane on the next lap
Reason for Use:
Shown when there has been an infringement or other problem
Black and White Diagonal Flag
Driver Action:
Correct driving behaviour or standards
Reason for Use:
Warning flag shown when driver is behaving in an unsportsmanlike manner
Chequered Flag
Driver Action:
Cease racing and return to pits or paddock
Reason for Use:
Marks the completion of the race or session
Blue Flag
Driver Action:
Check mirrors and prepare to be overtaken
Reason for Use:
Usually waved when a faster car is approaching or attempting to overtake a lapped car
Green Flag
Driver Action:
Resume racing
Reason for Use:
All clear ahead (usually after an incident zone)
Black with Orange Disc Flag (Meatball)
Driver Action:
Stop at pit on the next lap
Reason for Use:
Vehicle has a mechanical problem which may cause a safety hazard
Red Flag
Driver Action:
Stop racing, return to the grid or pitlane (as directed), be prepared to stop at any point, NO OVERTAKING
Reason for Use:
The race or session must be stopped for safety reasons, usually an on-track incident
Red and Yellow Striped Flag
Driver Action:
Use caution the racing surface is degraded or slippery
Reason for Use:
The circuit is breaking up, or oil/coolant or debris on surface
White Flag
Driver Action:
Use caution, slow moving vehicle on the circuit
Reason for Use:
Slow moving racecar or service vehicle on the circuit
Yellow Flag
Driver Action:
Slow, use caution, be prepared to stop or take avoiding action, NO OVERTAKING
Reason for Use:
An incident or obstruction on the circuit. Waved if partial blockage of the track, double-waved if significant blockage