Letter (alphabet) of sounds to make words. A letter is classed as either a consonant or a vowel, depending on how its sound is produced (vowels are "a", "e", "i", "o", "u", and sometimes "y" and "w"). The basic Roman alphabet is used by about one hundred languages, with slight variations. Some versions contain as few as twenty-one characters, some as many as thirty. Letters have specific names associated with them, which may differ with language, dialect, and history. "Z", for example, is usually called "zed" in all English-speaking countries except the US, where it is named "zee". As elements of alphabets,
Telegraph code limited character set available in Baudot code. Demand for lowercase letters and more punctuation marks led to teleprinters with a 6-bit TeleTypeSetter (TTS) code, and later, 7-bit ASCII code. In 1931, the International Code of Signals, originally created for ship communication by signalling using flags, was expanded by adding a collection of five-letter codes to be used by radiotelegraph operators. Telegraph code A telegraph code is one of the character encodings used to transmit information through telegraphy machines. The most famous such code is Morse code. Morse code can be transmitted and received with very simple electrical equipment, such as