If, after a notice of appeal has been filed, the parties are able to agree on a settlement of the case, the appellant must immediately serve and file a Notice of Settlement letting the court know that the case is settled. In a limited civil case (a civil case involving an amount that is $25,000 or less), this notice must be filed with the appellate division of the superior court. In an unlimited civil case (such as a civil case involving an amount over $25,000 or a family law case), this notice must be filed with the Court of Appeal (if the record on appeal has not yet been filed in the Court of Appeal, a copy must also be served on the superior court clerk).
Within 45 days of filing the Notice of Settlement (or longer if ordered by the court), the appellant must either abandon or dismiss the appeal, depending on when the Notice of Settlement was filed.
For the requirements for a notice of settlement in the appellate division, read rule 8.825 of the California Rules of Court.
For the requirements for a notice of settlement in the Court of Appeal, read rule 8.244 of the California Rules of Court.