Exchange Names for Phone Numbers

You know how in older TV shows (I Love Lucy) or movies, people would give their phone number as Jupiter 5-1234? You can look up the official names for the first two digits of your phone number at Ma Bell’s Officially Recommended Exchange Names. Pretty neat. It reminds of an old joke:

A little girl answers the phone, and says her mommy isn’t there. The caller asks her to take a message. “Please have you mommy call me at Capital 2-3456.” The little girl says “I don’t know how to make a capital 2.”