(a) Where prescriptions concerning national security prevent the transmittal of the record copy by the receiving Office to the International Bureau under Rule 22.1(a), the receiving Office shall notify the applicant and the International Bureau accordingly.
(b) The notifications under paragraph (a) shall be sent before the expiration of 13 months from the priority date. Where the receiving Office believes that national security clearance is imminent, it may postpone the sending of the notifications, but shall send them before the expiration of 17 months from the priority date if no clearance has been given by that time.