750 ILCS 75/50: Application of the Civil Practice Law.

The provisions of the Civil Practice Law shall apply to all proceedings under this Act, except as otherwise provided in this Act. A proceeding for dissolution of a civil union or declaration of invalidity of a civil union shall be entitled "In re the Civil Union of ... and ...". The initial pleading in all proceedings under this Act shall be denominated a petition. A responsive pleading shall be denominated a response. All other pleadings under this Act shall be denominated as provided in the Civil Practice Law.