Why 'BUtterfield 8'?

Is the old thread on this subject gone already?

The answer, anyway, is because that was a common way to write phone numbers in the old days. If you look at old ads or signs, you'll come across it.

The exchange of her answering services was BU8 (or, in modern parlance, 288). Back when exchanges had names, it was called "butterfield." To clarify the part you dialed, people often capitalized those two letters. When exchanges were more local than they are now, 288 gave people the impression you were on the Upper East Side.

Have you ever wondered what they're telling you to do when they tell you to "call PEnnsylvania 6-5000"? They're suggesting you call 736-5000, which is the phone number of the Hotel Pennsylviania.

A few others from old songs:
BEechwood 4-5789
TIdweater 4-1009

Occasionally in an old movie or TV show, someone will give a phone number as KLondike 5-something. That, of course, is 555, which has always been a "dummy" exchange that's not actually used.