To cast a vote, a voter who has been issued with a ballot-paper must—
(a) write "YES" or "NO" on the ballot-paper in accordance with the directions shown on the ballot-paper; and
(b) enclose the ballot-paper in the ballot-paper envelope and sign the envelope in the space provided; and
(c) place the ballot-paper envelope with its enclosed ballot-paper in the return envelope; and
(d) post or deliver the return envelope to the returning officer so as to be received by the returning officer before the close of voting in the poll.