The Preppy reference article from the English Wikipedia on 24-Jul-2004
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Preppy

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Preppy is a description of a person who behaves or dresses in a manner reminiscent of a student at a "preparatory school" (a private middle school or high school).

Typically, this would be a member of the upper or upper middle class who dresses in Polo, Lacoste, or Ralph Lauren clothing, often with their shirt collar turned upwards, or a sweater tied around their neck.

The name is similar in formation to hippie or yuppie, and had greater currency in the 1970s and 1980s.

There are regional preppy styles, most notably in the South.