Cal. Elec. Code § 2106

A program adopted by a county pursuant to Section 2103 or 2105, that is designed to encourage the registration of electors, shall, with respect to a printed literature or media announcement made in connection with these programs, contain this statement: “A person entitled to register to vote must be a United States citizen, a resident of California, not in prison or on parole for the conviction of a felony, and at least 18 years of age at the time of the election. A person may preregister to vote if he or she is a United States citizen, a resident of California, not in prison or on parole for the conviction of a felony, and at least 17 years of age.” A county elections official may continue to use existing materials prior to printing new or revised materials required by any changes to this section.