phpdoc comments for arguments read via func_get_args()

Hi, what is the preferred way of documenting methods that can accept an arbitrary (with potentially a minimum) number of parameters. for example here i want to support 2 or more parameters.

    /**
     * returns string to concatenate two or more string parameters
     *
     * @return string to caoncatenate two strings
     * @access public
     */
    function concat($value1, $value2)
    {
        $args = func_get_args();
        return "(".implode(' || ', $args).")";
    }

regards, Lukas