When race stewards and officials need to send a message to Formula 1 drivers on track, they can call on teams to relay the information over the radio, or can throw up a flag around the track to instantly alert drivers. Marshals at F1 circuits can wave nine different flags, and some are used a lot more than others.<br>At the start of every race, the green flag is waved to indicate that the track is ...<a class='more' href='https://www.autosport.com/f1/news/mon-these-are-the-least-used-flags-in-formula-1/10789342/?utm_source=RSS&utm_medium=referral&utm_campaign=RSS-ALL&utm_term=News&utm_content=uk'>Keep reading</a>