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 abbreviations sentences and questions in short three character codes each beginning with the character Q. For example, the code word QTH means "My location is". If this code word is followed by a question mark as QTH? it means "What is your location?". Typically very few full words will be spelled out in Morse code conversations. Often vowels are left out to shorten transmissions and turn overs. Other examples, of internationally recognized usages of Morse code abbreviations and well known code numbers, such as those of the Phillips Code from past eras of telegraph technology, are usages such as WX for