Cal. R. 3.510
Except as otherwise provided in the rules in this chapter, all papers filed or submitted must be accompanied by proof of prior service on all other parties to the coordination proceeding, including all parties appearing in all included actions and coordinated actions. Service and proof of such service must be made as provided for in civil actions generally.
Except as provided in rule 3.506(c), any party for whom liaison counsel has been designated may be served by serving the liaison counsel.
Failure to serve any defendant with a copy of the summons and of the complaint, or failure to serve any party with any other paper or order as required by the rules in this chapter, will not preclude the coordination of the actions, but the unserved defendant or party may assert the failure to serve as a basis for appropriate relief.
Cal. R. Ct. 3.510