I have found that with the handful of legitimate urgent emergencies I have been involved with, plain language has been used. 'ABC, taxiway A1, we are on fire' would get the trucks rolling. One guy conducting a forced landing on a beach responded to my request for a mobile phone number with just the didgets, no call sign! Oh the humanity, I can't believe he would have violated standard RT like that. Some of you dudes have far too much time to worry about this stuff
