public static function get_delimiter_list() {
        global $CFG;
        $delimiters = array('comma'=>',', 'semicolon'=>';', 'colon'=>':', 'tab'=>'\\t');
        if (isset($CFG->CSV_DELIMITER) and strlen($CFG->CSV_DELIMITER) === 1 and !in_array($CFG->CSV_DELIMITER, $delimiters)) {
            $delimiters['cfg'] = $CFG->CSV_DELIMITER;
        }
        return $delimiters;
    }