PS
There's also a Q code for "put a competent operator on the set", used to great effect by the Trucial Oman Scouts Arab boy signallers (11-14) at Sharjah when communicating with visiting Royal Navy vessels.
The boys, who spoke not a word of English, were for that reason incredibly fast Morse senders and receivers, and did not suffer fools gladly when asked to repeat a message.
Sorry, thread drift!