So what look defines "Punk"?  This is what I think Punk Clothing is:

Punk fashion is done to separate one's self from society, and is meant to elicit a reaction from outsiders.  Punks tend to show their love for a certain band or idea by pin-back buttons or patches which they adorn on their jackets.  Punks enjoy stage diving, crowd surfing, skanking, pogoing, hardcore dancing and moshing. 
Typically, punks are adolescents or young adults from a working class or a middle class background.  Punks and skinheads have had both antagonistic and friendly relationships, depending on the situation.  Sometimes faced abuse from Rednecks and other right-wing groups such as the Nazi-Skinheads, Punks and Dreads seem to flourish together, even though, the Dread culture is more alien, with its religious talk of revelations and prophecies.  Punk literature, in the form of “fanzines” and newsletters, deliver ideas and messages about things in and out of the “scene”.  The Goth subculture began in the gothic rock scene, a music genre that evolved from punk rock and post-punk in the late 1970s.