public function getBinary()
    {
        $sid = explode('-', ltrim($this->value, 'S-'));

        $level = (int) array_shift($sid);

        $authority = (int) array_shift($sid);

        $subAuthorities = array_map('intval', $sid);

        $params = array_merge(
            ['C2xxNV*', $level, count($subAuthorities), $authority],
            $subAuthorities
        );

        return call_user_func_array('pack', $params);
    }