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
American Morse code shorter dash, leads to the advantage of a more compressed code and a faster sending rate. The same operator could send at least 20% faster with American Morse than with International Morse. The greater complexity of American Morse meant that it was easier for operators to make errors. American Morse has multiple lengths of dashes and spaces and inadvertently transmitting the wrong ones and other timing errors by novice operators is known as hog-Morse. Over time, with the disappearance of landline telegraphy, and the end of commercial radio use of Morse Code, American Morse has become nearly extinct in some