Cal. Rules of Court, rule 8.976

(a) Filing of decision

The appellate division clerk must promptly file all opinions and orders in proceedings under this chapter and on the same day send copies (by e-mail where permissible under rule 2.251) showing the filing date to the parties and, when relevant, to the small claims court.

(b) Finality of decision

(1) Except as otherwise ordered by the appellate division judge, the following decisions regarding petitions for writs under this chapter are final in the issuing court when filed:

(A) An order denying or dismissing such a petition without issuance of an alternative writ, order to show cause, or writ of review; and

(B) An order denying or dismissing such a petition as moot after issuance of an alternative writ, order to show cause, or writ of review.

(2) Except as otherwise provided in (3), all other decisions in a writ proceeding under this chapter are final 30 days after the decision is sent by the court clerk to the parties.

(3) If necessary to prevent mootness or frustration of the relief granted or to otherwise promote the interests of justice, a judge in the appellate division may order early finality of a decision granting a petition for a writ under this chapter or denying such a petition after issuing an alternative writ, order to show cause, or writ of review. The decision may provide for finality on filing or within a stated period of less than 30 days.

(c) Modification of decisions

Rule 8.888(b) governs the modification of decisions in writ proceedings under this chapter.

(d) Remittitur

The appellate division must issue a remittitur after the judge issues a decision in a writ proceeding under this chapter except when the judge issues one of the orders listed in (b)(1). The remittitur is deemed issued when the clerk enters it in the record. The clerk must immediately send the parties notice of issuance of the remittitur, showing the date of entry.