Morse code in Cayo Largo del Sur, Cuba is coded as "UCL", and UCL in Morse code is transmitted on its radio frequency. In some countries, during periods of maintenance, the facility may radiate a T-E-S-T code () or the code may be removed which tells pilots and navigators that the station is unreliable. In Canada, the identification is removed entirely to signify the navigation aid is not to be used. In the aviation service, Morse is typically sent at a very slow speed of about 5 words per minute. In the U.S., pilots do not actually have to know Morse to
Morse code abbreviations provided by the prosigns for Morse code, the International Q code, Z code, RST code, the telegraph era Phillips Code and many well known Morse code abbreviations as discussed in this Wikipedia article. Together all of these traditional conventions serve as a somewhat cryptic but commonly understood language (Lingua Franca) within the worldwide community of amateur radio Morse code operators. These codes and protocols efficiently encode many well known statements and questions from many languages into short simple character groups which may be sent manually very quickly. The international Q code for instance encodes literally hundreds of full normal language