Morse code was later made the standard by the International Telecommunication Union (ITU). Morse's original code specification, largely limited to use in the United States and Canada, became known as American Morse code or "railroad code". American Morse code is now seldom used except in historical re-enactments. In aviation, pilots use radio navigation aids. To ensure that the stations the pilots are using are serviceable, the stations transmit a set of identification letters (usually a two-to-five-letter version of the station name) in Morse code. Station identification letters are shown on air navigation charts. For example, the VOR-DME based at Vilo Acuña Airport
Morse code abbreviations been used. In fact, in the above example S1 and S2 might not speak the same native language. Of course, real rag-chewing (lengthy conversations) could not be accomplished by non-native speakers without such a common language. Contesters often use a very specialized and even shorter format for their contacts. Their purpose is to process as many contacts as possible in a limited time (e.g. 100–150 contacts per hour). Morse code abbreviations Morse code abbreviations are used to speed up Morse communications by foreshortening textual words and phrases. Morse abbreviations are short forms representing normal textual words and phrases formed from