Any party serving discovery shall file a certificate of service of discovery document. {Amended April 22, 2013}.In many civil actions, before the case is resolved there takes place a process known as pretrial discovery. This summary describes this process. Any party serving discovery shall file a certificate of service of discovery document. Ill. The full name and complete last known address of every witness to the occurrence complained of. This guide is intended to be a summary of basic discovery procedures. Start your Service of Process at the Clerk of the Circuit Court. The clerk has one office at every courthouse and multiple at the Richard J. Daley Center. You could be anywhere in the world, and operating under any number of private or public mediation procedural rules.