min yin has been telling me about the different emergency codes that her hospital uses for paging on the overhead. (everyone is supposed to come running.):

code grey, she tells me, is patient aggression. code black is patient aggression involving weapons (and police), code red is for fire, purple is for bomb threat, and my favourite, code yellow: "internal disaster."

me, chortling: internal disaster? what constitutes an internal disaster?!
minyin: well, once there was "code yellow! the paging system is down!