California Code, Family Code - FAM § 9208

(a) The clerk of the superior court entering a final order of adoption concerning an Indian child shall provide the United States Secretary of the Interior or a designee with a copy of the order within 30 days of the date of the order, together with any information necessary to show the following:

(b) If the court records contain an affidavit of the biological parent or parents that their identity remain confidential, the court shall include that affidavit with the other information.