(4) Every person attending the proceedings in connection with the issue or the receipt of ballot papers for persons voting by post shall maintain and aid in maintaining the secrecy of the voting and shall not –
(a) except for some purpose authorised by law, communicate, before the poll is closed, to any person any information obtained at those proceedings as to the official mark; or
(b) except for some purpose authorised by law, communicate to any person at any time any information obtained at those proceedings as to the number or other unique identifying mark on the back of the ballot paper sent to any person; or
(c) except for some purpose authorised by law, attempt to ascertain at the proceedings in connection with the receipt of ballot papers the number or other unique identifying mark on the back of any ballot paper; or
(d) attempt to ascertain at the proceedings in connection with the receipt of the ballot papers the candidate for whom any vote is given in any particular ballot paper or communicate any information with respect thereto obtain at those proceedings.