6.—(1) Each postal ballot paper issued shall be stamped with the official mark which shall perforate or emboss the ballot paper and the name and number in the register of electors shall be called out, and such number shall be marked on the counterfoil, and a mark shall be placed in the list of postal voters against the number of the elector to denote that a ballot paper has been issued to the elector or his proxy but without showing the particular ballot paper issued.
(2) The number of a postal ballot paper shall be marked on the declaration of identity sent with that paper.