Morse code most common letter in English, the letter "E", has the shortest code: a single dot. Because the Morse code elements are specified by proportion rather than specific time durations, the code is usually transmitted at the highest rate that the receiver is capable of decoding. The Morse code transmission rate ("speed") is specified in "groups per minute", commonly referred to as "words per minute". Morse code is usually transmitted by on-off keying of an information carrying medium such as electric current, radio waves, visible light or sound waves. The current or wave is present during time period of the dot
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