Voting Procedure during Referendum
135.1. Voting during a referendum shall be conducted in accordance with Articles 104 and 105 of this Code.
135.2. A voter shall mark an empty square to the right of the answer on the referendum ballot paper by choosing one of the responses “for” or “against” (“yes” or “no,” “I agree” or “I disagree”) proposed on the referendum.
135.3. The vote shall be considered invalid if both squares are marked or remain unmarked.