(1) If the address of the addressee cannot be established, or if notification in accordance with Rule 78, paragraph 1, has proved to be impossible even after a second attempt by the European Patent Office, notification shall be effected by public notice.
(2) The President of the European Patent Office shall determine how the public notice is to be given and the beginning of the period of one month on the expiry of which the document shall be deemed to have been notified.