Operating signals

• Prosigns for Morse code
• 92 Code: telegraph brevity codes
• Q code: initially developed for commercial radiotelegraph communication and adopted by other radio services
• QN Signals: published by the ARRL and used in Amateur radio
• R code and S Code: published by the British Post Office for coastal wireless stations and ships
• X code: used by European military services in wireless telegraphy
• Z code: used in early radiotelegraph communication