The phrase "green flag" is often used to indicate that something is good to go or allowed to proceed. It represents a positive signal or a sign of permission to start or continue with a particular action or event. Full definition
As a front closed in with fewer than 32 laps remaining, Osborne elected to keep Buescher on the track during a sequence of green flag pits, jumping him into the lead. (sbnation.com)
Featuring reviews of Jesmyn Ward «s «The Fire This Time» and «We Gon» Be Alright» edited by Jeff Chang, two essay collectiosns about race in America, the latest issue of Book Forum is covered by an illustration of a tattered red, black and green flag on the cover that resembles David Hammons «s «African - American Flag.» (culturetype.com)