Add Yahoo as a preferred source to see more of our stories on Google. Like our social security numbers, birth dates, and phone numbers, our ZIP codes are one of many seemingly random number sequences ...

Most Americans know their ZIP code by heart. They type it into online forms, scribble it on envelopes and memorize it as part of their address. But not everyone knows the original meaning of the term.

Everyone has memorized exactly two ZIP codes: 90210 and whatever their own ZIP code is. We can thank a certain TV show set in Beverly Hills for that. Aside from that, general knowledge of these ...