An Illinois Subpoena is a court order issued by a court in the state of Illinois which requires a person or an entity to appear in court or provide documents, testimony, or other evidence in a legal proceeding. There are four types of Illinois Subpoena: Subpoena Ducks Cecum, Subpoena Ad Testificandum, Subpoena to Produce Documents, and Subpoena to Appear and Testify. A Subpoena Ducks Cecum requires a person or entity to appear in court and produce certain documents or other tangible items. A Subpoena Ad Testificandum requires a person to appear in court to testify. A Subpoena to Produce Documents requires a person or entity to produce certain documents or other tangible items. Lastly, a Subpoena to Appear and Testify requires a person to appear in court to testify and to produce certain documents or other tangible items.