The way it was explained to me was that it's an indication to another follow rider that you're looking out for each other. Kind of like a secret handshake to an exclusive club. In other words, no waving to the cages unless they have you in the crosshairs and refuse to hang up. But then you have other problems to deal with.
Feel free to correct me if I'm wrong, it's happened before and will happen again.
87 vn750at least that is what the frame #'s say
"Squirrel Bike" aka Jersey
Rat bike with a good PR agent
shaved and coastered
2 into 1 exhaust
rear 170 and front 110
custom dash with voltmeter
Recovered seat without "butt hammers"
More to come
Praise to the Parts Goddess Crobins for needed things
When someone tells me "Great minds think alike" all I can think is "You Pervert"