California Code, Elections Code - ELEC § 13501

(a) The Secretary of State shall include in the state voter information guide the information specified in subdivision (a) of Section 9083.5, including a statement explaining that a voter who has declined to disclose a political party preference may not vote in a political party's primary election unless the political party has authorized a voter who has declined to disclose a political party preference to vote in its primary election.

(b) The Secretary of State shall make all of the following information available on the Secretary of State's Internet Web site:

(c) A county elections official shall include all of the information described in paragraphs (1) to (3), inclusive, of subdivision (b) in the nonpartisan county voter information guide prepared pursuant to Section 13300 and shall make the information available on the official's Internet Web site.  In addition, the county elections official shall send an email to the email address of a voter who has declined to disclose a political party preference notifying the voter that he or she may request a political party's ballot at the next ensuing partisan primary election if the political party has so authorized.  The county elections official shall also provide the notice to a voter who has declined to disclose a political party preference by text message if the voter has provided written consent to receive text messages from the county elections official.