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[Steven Champeon <schampeo AT hesketh.com>]

on Thu, Oct 23, 2003 at 03:14:49PM -0400, Diana Duncan wrote:
> I heard that this song was one of the main reasons the film industry 
> now uses "555" as the exchange for all phone numbers, as it is never 
> used as a real exchange (except for information 555-1212).

Actually, that's why 555 was set aside, like example.{com,net,org} were
- for use in such contexts. But the interesting story is how they chose
that particular exchange. I remember hearing about this from my mom - my
grandfather worked for AT&T and later New England Telephone after the
breakup; if you ever drive around the northeast (Maine, Mass, NH) and
you see the little cinder block telephone buildings on the side of the
road, you've seen a mark my grandfather left on the countryside ;) He
designed them back in the fifties, IIRC, and they're still using the
same building design today, or were recently, anyway. OK, enough of
that. On to the '555' thing.

It goes back to the days when exchanges were based on place names, like
PEnnsylvania 6-5000 (736-5000); KLondike-5 wasn't a real exchange,
either, and showed up a lot in movies before the place name exchange
system was dropped in favor of simple digits. Turns out (after a bit of
googling) that the letters "JKL" don't start very many American place
names, Klondike apparently being an exception, so the '555' exchange
was left aside for administrative stuff like the Directory Assistance
number (555-1212) you mention above.

More here:

 http://atcseditor.freeyellow.com/code.htm

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