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
History of the International Phonetic Alphabet closely connected that the whole might be treated as a single sound", were noted as able to be represented with a tie bar, as in . Palatalized consonants could be marked by a dot above the letter, as in , "suggesting the connexion with the sounds i and j". The 1921 "Écriture phonétique internationale" introduced new symbols, some of which were never to be seen in any other booklet: The book also mentioned symbols "already commonly used in special works", some of which "have not yet been definitively adopted": It also introduced several new suprasegmental specifications: It recommended the use