def reply_inform(cls, req_msg, *args):
        """Helper method for creating inform messages in reply to a request.

        Copies the message name and message identifier from request message.

        Parameters
        ----------
        req_msg : katcp.core.Message instance
            The request message that this inform if in reply to
        args : list of strings
            The message arguments except name

        """
        return cls(cls.INFORM, req_msg.name, args, req_msg.mid)