Morse code become commonly available until around 1920. Until 2003, the International Telecommunication Union mandated Morse code proficiency as part of the amateur radio licensing procedure worldwide. However, the World Radiocommunication Conference of 2003 made the Morse code requirement for amateur radio licensing optional. Many countries subsequently removed the Morse requirement from their licence requirements. Until 1991, a demonstration of the ability to send and receive Morse code at a minimum of five words per minute (wpm) was required to receive an amateur radio license for use in the United States from the Federal Communications Commission. Demonstration of this ability was still
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