Cal. Civ. Proc. Code § 412.20
(a) Except as otherwise required by statute, a summons shall be directed to the defendant, signed by the clerk and issued under the seal of the court in which the action is pending, and it shall contain:
(6) The following introductory legend at the top of the summons above all other matter, in boldface type, in English and Spanish:
“Notice! You have been sued. The court may decide against you without your being heard unless you respond within 30 days. Read information below.”