Cal. Elections Code § 2264

(a) Every driver’s license application shall include a voter registration application. All of the following apply to the voter registration application included with the driver’s license application: (1) The voter registration application shall require only the minimum information necessary to prevent duplicate voter registrations and to enable the Secretary of State to assess the eligibility of the applicant and to administer voter registration and other procedures for elections. (2) The voter registration application shall not require any information that duplicates information required for the driver’s license application, other than an additional signature or other information required by paragraph (3). (3) The voter registration application shall include all of the following: (A) A statement of the voter eligibility requirements, including those regarding citizenship. (B) An attestation that the applicant meets each voter eligibility requirement. (C) The signature of the applicant, under penalty of perjury. (D) An opportunity to decline to register to vote. (b) A voter who attests to the voter’s eligibility shall be registered to vote unless the voter affirmatively declines to register to vote.