California Code, Elections Code - ELEC § 15377

(a) The elections official shall identify and provide to the Secretary of State within 31 days of the election the number of vote by mail ballots rejected, categorized according to the reason for the rejection. The Secretary of State shall provide uniform vote by mail ballot rejection reason codes for each category of rejection to be used by elections officials for reporting under this section.

(b) Upon receipt of the information described in subdivision (a), the Secretary of State shall publish a report containing the information for every statewide election, including a recall election for a state constitutional officer, Member of the State Senate, or Member of the State Assembly, and every special election to fill a vacancy for the office of Member of the United States Senate, Member of the United States House of Representatives, Member of the State Senate, and Member of the State Assembly on the Secretary of State's internet website.