Page "Morse code" Paragraph 2

Each character ( letter or numeral ) is represented by a unique sequence of dots and dashes.

The duration of a dash is three times the duration of a dot.

Each dot or dash is followed by a short silence, equal to the dot duration.

The letters of a word are separated by a space equal to three dots ( one dash ), and two words are separated by a space equal to seven dots.

The dot duration is the basic unit of time measurement in code transmission.

For efficiency, the length of each character in Morse is approximately inversely proportional to its frequency of occurrence in English.

Thus, the most common letter in English, the letter " E ," has the shortest code, a single dot.