A real prep doesn't wear American Eagle, Hollister, or Aeropostale. A real prep doesn't touch Abercrombie (it's tasteless garbage and nobody with class would wear shirts with slogans). Preppy is Polo, Lacoste, Burberry, Lilly Pulitzer, pearls, loafers, popped collars, plaid, madras, crewneck sweaters with ponies/palm trees/etc on them. Preppy is huge sunglasses, anything excessive, expensive, or lavish. Preps belong to country clubs, play sports with racquets, spend summers on the Vineyard, at the Hamptons, or in Nantucket, and wouldn't be caught dead cheerleading. And one more thing - money. Old or new, but preferably old.
"I can't believe that people think that any slutty high school girl not wearing black nail polish is preppy! Preps have class."