poppin the collar

flipping up the collar of a shirt most likely a polo means normally your a pimp or just a prep

The stupid act of flipping up your collar on your polo to look "fly" even though you end up looking like a complete fool.

the act of flipping up the collar of a Ralph Lauren polo shirt done by preppy kids or frat dudes who are pimps

To pimp and/or being a player. Showin' off after workin' it.

That's urban slang for pimpin', stunnin', or lookin' fly made popular by the rap group 3 six mafia. Or if someone wants their respect or recognition for doing something. Kind of like when the Fonze on 'Happy Days' use to turn his collar up to be cool.

pimps pop their collars to call their hoes over to get paid.

A phrase generally used in the hip hop lexicon. It describes not only an action, but also a general attitude. The term was originally used in this sense by the rapper E-40. When used by E-40, and many other hip hop artists including Three 6 Mafia in their song Poppin My Collar, the term refers to the act of pulling one's collar, or the clothing where one's collar would be (as when wearing a t-shirt), with the thumb and fingertips. One then releases the clothing in varying degrees of flamboyance. Used in this sense, "poppin' ya collar" is more about the attitude and message of confidence portrayed in so doing than any clothing style (see upturned collar). E-40 immortalized the term (and the accompanying attitude), in his song Pop Ya Collar from his album Loyalty and Betrayal.