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 for non-Latin alphabets for more Indian languages. See Wabun code. See Chinese telegraph code. See SKATS. See Morse code for non-Latin alphabets This is a summary of the use of Morse code to represent alphabets other than Latin. The Greek Morse code alphabet is very similar to the Latin alphabet. It uses one extra letter for Greek letter "Χ" and does not use the codes for Latin letters "J", "U" and "V". The "tonos" is not transmitted in Morse code; the receiver can simply infer which vowels require one. The "Greek diphthongs" presented in the bottom three rows of the table are specified