F1SI 1985/454
17[F2(1)Every ballot paper must contain an appropriate security marking (the official mark).]
(2)The official mark shall be kept secret, and an interval of not less than seven years shall intervene between the use of the same official mark at elections for the same district electoral area.
[F3(3)The returning officer may use a different official mark for different purposes at the same election.]
F2Sch. 5 rule 17(1) substituted (1.7.2008) by Electoral Administration Act 2006 (c. 22), ss. 47, 77(2), Sch. 1 para. 60(2); S.I. 2008/1316, art. 2(3), 5(f)(iii)
F3Sch. 5 rule 17(3) substituted (1.7.2008) by Electoral Administration Act 2006 (c. 22), ss. 47, 77(2), Sch. 1 para. 60(3); S.I. 2008/1316, art. 2(3), 5(f)(iii)