Rules on Civil Procedure
Section 1. Caption. - The caption sets forth the name of the court, the title of the action, and the docket number if assigned.
The title of the action indicates the names of the parties. They shall all be named in the original complaint or petition; but in subsequent pleadings, it shall be sufficient if the name of the first party on each side be stated with an appropriate indication when there are other parties.
Their respective participation in the case shall be indicated. (1a, 2a)