4.—(1) There shall be two objection periods, called the first objection period and the second objection period.
(2) The first objection period shall begin on 1st October 1968 and end on 30th September 1970, and the second shall begin on 1st May 1970 and end on 30th April 1972.
(3) Where a registration is made before 1st July 1968 an objection to it shall not be entertained unless it is made during the first objection period, and, where a registration is made after 30th June 1968, an objection to it shall not be entertained unless it is made during the second objection period.