in file ISO639.php, variable Text_LanguageDetect_ISO639::$nameToCode2 Maps all language names from the language database to the ISO 639-1 2-letter language code.
$nameToCode3
in file ISO639.php, variable Text_LanguageDetect_ISO639::$nameToCode3 Maps all language names from the language database to the ISO 639-2 3-letter language code.