California Code, Revenue and Taxation Code - RTC § 4837

The date and nature of the correction shall be entered on the roll on which the error was made or on the delinquent abstract prepared therefrom opposite the description of property;  provided, however, that where the correction is to a prior year's roll and results in an increase in taxes, if the delinquent tax abstract prepared from such roll does not list that parcel or account, the correctional entry to the delinquent abstract may be made by insertion therein of a new sheet containing the information required to be set forth by Section 4372 and the date and nature of the correction.  The written authority for the correction shall be filed and preserved by the auditor as a public record.  The auditor shall make any necessary changes in accounts with the tax collector.