Fred Bauder said:
Here's an example of a minor secret which I would
never divulge or
publish:
I used to work for a company which had radio communications with a
central dispatcher. We had a secret word which if used alerted the
dispatcher that there was a serious problem. It was a pretty nifty
system and as far as I know, none of the thousands of people who ever
worked for that company ever let that secret out.
Oh have you ever been in a railway station or something and heard an
announcement that goes something like "This is a security announcement:
will Mr Green please contact security immediately." This gets repeated a
few times, with emphasis on "Mr Green". And then if you look up and stay
alert, you'll see rather a lot of transport police moving around,
spreading through the station, about as discreetly as they can, looking
like they all just happened to be in the station at the same time.
The point is to let the staff know to be ready for a possible evacuation,
without panicking the public. Stores use similar codes to tip off the
security guards at the exit when a thief is spotted.