Cal. ELEC § 14227.5

(a) At a partisan primary election, before providing a voter who has declined to disclose a political party preference with a nonpartisan ballot or before the voter enters the voting booth, as applicable, a member of the precinct board shall provide a uniform notification to the voter informing him or her that he or she may request a political party’s ballot and the name of each political party that has authorized a voter who has declined to disclose a political party preference to vote in its ballot. (b) A county elections official shall train the members of a precinct board regarding their duties under subdivision (a).