California Code, Elections Code - ELEC § 13204

(a) The instructions to voters shall be printed below the ballot identification and above the contests to be voted on, or in the first column of the ballot as long as no contest is placed below the instructions in that column. The instructions shall be in at least 10-point type and in an area clearly separated from the ballot contests.

“Instructions for voting

To vote for a candidate, completely fill in the [voting target] next to the candidate's name or the word “Yes” or “No.”

To vote for a qualified write-in candidate, write the name in the blank space provided and fill in the [voting target].

If you make a mistake, [instructions for making a correction] [or ask for a new ballot].

Make sure your vote counts.

Use a [blue or black ballpoint pen].

Do not select more candidates than the number to be elected. You may vote in as many or as few contests as you want.

A mistake in one contest does not affect the rest of the ballot.”

(d) The instructions may be accompanied by illustrations, customized to the ballot design in each county, that show the correct way of marking a selection on the ballot, writing in a candidate name, or correcting a mistake.