Of, pertaining to, or referring to alphanumeric characters (letters and numbers): "When used with reference to computer input and output, the alphanumerical set usually includes the upper-case and lower-case alphabetic characters (A–Z, a–z), the numeric characters (0–9), and special characters; such as, the symbols $, #, %, &, +, *, and @, plus any mathematical symbols and punctuation marks."

While typically the phrase "alphabetic characters" means only English letters, an alphanumerical 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)."