I have an original "Q-Code" booklet back home in Aus, dating back to 1927. Before voice comms all communication was completed by sending a morse "Q" message. 'QRT' by memory was "stop sending" etc.(or was it QTT?). Today, all is left is 'QNH' and I suppose 'QFE', 'QDM' and 'R'. We still get asked to do a 'QDM' in the Sim by the older instructors. Why were all the messages prefixed by 'Q'? I was told it was because of the distinct sound of 'Q'....."here comes the bride", dah, dah, dit dah. This gave adequate warning of the message to come. Amazing how much useless information is stored in ones brain. I learnt morse by tapping out the menu with my dinner fork, drove the wife up the wall.