(a) Who Must File; Contents. A nongovernmental corporate party must file two copies of a disclosure statement that:
   (1) identifies any parent corporation and any publicly held corporation owning 10% or more of its stock; or
   (2) states that there is no such corporation.
(b) Time to File; Supplemental Filing. A party must:
   (1) file the disclosure statement with its first appearance, pleading, petition, motion, response, or other request addressed to the court; and
   (2) promptly file a supplemental statement if any required information changes.