Humans are innately tribal, are we not? We have ways of communicating our tribal identifications by dress, manners, comportment, tone of speech, appearance, etc.
People can almost instantly identify a fellow tribesman/woman, and can just as easily tell the real from the fake (eg, Ralph Lauren Polo is fake).
Here's the preppiest website I have ever seen. It's for real, and done by a gal named Muffy: The Daily Prep.