-n.- refers to the Town of Upper Marlboro in Prince George's County Maryland, which is not to be confused with the unincorporated Greater Upper Marlboro area that surrounds the town. UpMa is an abbreviation of the first two letters of the words "Upper Marlboro," and is used to distinguish the town from the surrounding area. It is the seat of Prince George's County, and features architecture dating back to the 18th Century. First settled in 1695, the town was named after John Churchill, the first Duke of Marlborough, an ancestor of Winston Churchill. Today the town is dominated by the Prince George's County Courthouse, County Administration building, and the Board of Education.
Person 1: "Hey, I heard you moved to Upper Marlboro, how's life in the middle of nowhere?"
Person 2: "Nowhere? You're thinking of Greater Upper Marlboro. I live in UpMa. We've got a downtown with bars and real sidewalks."