California Proof of Service of Response by Mail — Civil Harassment Prevention is a procedure used to serve legal documents on defendants in civil harassment cases. This process is typically initiated by the plaintiff, who is the party filing the civil harassment claim. The plaintiff will mail the documents to the defendant's address and must complete a Proof of Service of Response by Mail form to prove that the papers were served. The Proof of Service of Response by Mail must then be filed with the court. There are two types of California Proof of Service of Response by Mail — Civil Harassment Prevention: 1. Registered Mail: The plaintiff must mail the documents to the defendant's address using registered mail. The plaintiff will then receive back a green card or other proof of delivery form. This form must be completed and filed with the court. 2. Certified Mail: The plaintiff must mail the documents to the defendant's address using certified mail. The plaintiff will then receive back a yellow card or other proof of delivery form. This form must be completed and filed with the court.