The phenomenon wherein a cute boy wears a plaid shirt, and suddenly becomes 100% more attractive to all heterosexual females and homosexual males in the vicinity.
Jane: Whoa, did John get hotter?
Joseph: Nah, he's just following the plaid shirt rule.
The Armour of hipster apparel. A popular style of shirt in the 90s grunge scene, the shirt has been resurrected to be popular amongst Indie folk and rock acts who but them from a thrift store. To catch a fully suited hipster male, he'll be wearing the aforementioned plaid shirt, a band shirt under the plaid shirt, tight jeans, chucks, and a beanie.
Of course there are various fitting pieces of armour a hipster could wear, but this is a typical suit up.
Girl: Hey, nice plaid shirt
Guy: Thanks, I got it from the thrift store down the street
Girl: Oh wow! I just blogged about that place last week.
Guy: My name is Tom
Totally ghey. In the mid 1970's they were once thought of as cool. Now, abercrombie drones have sodomized the name and ruined yet another thing that was once cool.
By the way guys... You may find them cool, but your grandfather also has a pair. So...
The demographic of private- or parochial-schooled people, usually white females, who act in an excessively flamboyant manner, usually with some degree of sexual promiscuity. Derived from the typical color/pattern of schoolgirl uniforms.
What a bimbo! I bet she was top of her class in her Plaid Society.
Wearing plaid, as the stereotype goes, is a lesbian identifier . Typically , it is worn by masc/butch lesbians as a plaid shirt however for femme lesbians it is worn as a plaid skirt