Re:The origins of ‘horn ok please,’ India’s most ubiquitous ...
by VBprogrammer on Monday November 29, 2021 @12:20PM
(#29382425)
Flapping your arm like a child pretending to be a bird is another I've seen warning of a speed trap (it's actually the hand signal for "I'm slowing down" back in the days that was relevant).
Other motorcyclist signs are sticking the left leg out to say thanks, holding your hand out and rapidly opening/closing it to say "you've left your indicator on", and pointing at dangerous spots on the ground like potholes, gravel, or other unseen hazards.