Illinois Additional Defendant Signatures, Names, & addresses refer to the required information needed when filing a lawsuit in the state of Illinois. This information must be provided for each party in the lawsuit, including the plaintiff and the defendant. The information needed includes the signature, name, and address of the party being added as a defendant. Depending on the type of case, the information may also need to include the attorney’s name, address, and contact information. There are two types of Illinois Additional Defendant Signatures, Names, & addresses. The first type is for an individual defendant and the second type is for an entity such as a corporation or LLC. For an individual, the information needed is the signature, name, and address of the individual. For an entity, the information needed is the signature, name, and address of the registered agent, as well as the name and address of the company.