California Code, Water Code - WAT § 30779

The ballots shall contain the list of names and the respective offices as published in the proclamation and shall be in substantially the following form:

Instructions to Voters: To vote, stamp or write a cross (+) opposite the name of the candidate for whom you desire to vote. All marks otherwise made are forbidden. All distinguishing marks are forbidden and make the ballot void. If you wrongly mark, tear, or deface this ballot, return it to the inspector of elections and obtain another.