15.—(1) Where a ballot paper is received which bears the same number or barcode as a ballot paper already received, both that ballot paper and the other ballot paper bearing the same number or barcode (as the case may be) shall be void and not counted.
(2) Any ballot paper which is unsigned, unmarked or void for uncertainty shall, subject to sub paragraph (3), be void and not counted.
(3) A ballot paper on which the vote is marked–
(a)elsewhere than in the proper place; or
(b)otherwise than by means of a cross; or
(c)by more than one mark,
shall not for such reason be deemed to be void if the voting intention appears clear.