Illinois Additional Defendant Signatures, Names, & addresses are documents required by the court in Illinois when filing a lawsuit. These documents must include the names, addresses, and signatures of all individuals and businesses who are being sued. There are two types of Illinois Additional Defendant Signatures, Names, & addresses: 1) Affidavit of Service, and 2) Summons with Notice. The Affidavit of Service is the document used to serve the lawsuit to the defendant and must include the defendant’s name, address, and signature of the person who served the lawsuit. The Summons with Notice is the document used to notify the defendant of the lawsuit and must include the defendant’s name, address, and signature of the person who was served the lawsuit.