Area code of Detroit, Michigan. You dial it first when you want to phone somewhere (optional). When asked where they're from,
the natives sometimes reply either "(The) three one three" or "D'troit". The Detroit people are known for dressing very well (downtown, at least) and pronouce "Detroit" more like "Duh-troit." Not "Dee-Troyt" like the east coast/west coast people do. Speaking of
out of towners, it's not three-hundred-and-thirteen, you idiots!
Don't get me wrong, I lived in Detroit for 8 years (south-west), it's rather welcoming to foreigners. Hey, Eminem is from Kansas City.