I always flash high beams to an on coming car to warn traffic cop ahead waiting for speeders, on 2 lane highways. I do not belong to any gang, but I did serve local republican party as precinct representative for a few years.
Around here if somebody flashes their lights, they are warning you that they just made it through a herd of elk or cattle on the highway.
That’s kind of like a gang ;)
Up here it means look out ahead for our big 4 legged furry friends on the road!