California Code, Elections Code - ELEC § 2223

(a) In lieu of mailing a residency confirmation postcard to each registered voter in the county, the county elections official may include the return address of the county elections official's office on the outside portion of the county voter information guide or county voter information guide envelope mailed to the voter for an election conducted within the last six months preceding the start of the confirmation process, along with the statements “Address Correction Requested” and “Notice:  If the person named on the county voter information guide is not at the address, please help keep the voter rolls current and save taxpayer dollars by returning this county voter information guide to your mail carrier.”

(b) A voter not eligible for an election during the last six months preceding the start of the confirmation process, or a voter not mailed a county voter information guide with an address correction requested, shall have his or her address confirmed by either a residency confirmation postcard or an address verification mailing conducted pursuant to this article using NCOA/Operation Mail data pursuant to Section 2222 or consumer credit reporting agency data pursuant to Section 2227.