Yes, but you are rather missing the point.
Bealzebub: Quite how you drew that conclusion I am at a loss to know!
I was supporting the use of codes to indicate that certain actions should be taken/prepared for without setting the public on the alert until it is necessary/desirable to do so.
My illustration was (as was indicated) for a large public building which many contain upwards of 30,000 people. I was not advocating this phrase for use in the particular case being discussed, merely that forms of word do exist and are in routine use that achieve the desired effect, i.e. initiate action without unneccessary alarm.