alphanumeric (ălˌfənŏmĕrˈĭk) [key] or alphameric ălˌfəmĕrˈĭk, the set of letters and numbers. When used in reference to computer input and output, the set usually is expanded to include the upper- and lower-case alphabetic characters (A–Z, a–z), the numeric characters (0–9), and special characters (such as the symbols $, #, and @, mathematical symbols, and punctuation marks). While typically the phrase "alphabetic characters" means only English letters, an alphanumeric character set may also include letters from other languages that also use the Roman alphabet, such as an e with an acute accent ( é ) or a c with a cedilla ( ç ).
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