Source : WordNet®

alphanumeric
     adj : of or pertaining to alphanumeric characters [syn: {alphanumerical},
            {alphameric}, {alphamerical}]

Source : Free On-Line Dictionary of Computing

alphanumeric
     
         A decimal digit or a letter (upper or lower case).
        Typically, "letters" means only English letters ({ASCII} A-Z
        plus a-z) but it may also include non-English letters in the
        Roman alphabet, e.g., e-{acute}, c-{cedilla}, the {thorn
        letter}, and so on.  Perversely, it may also include the
        {underscore} character in some contexts.
     
        (1997-09-11)