The term caption is subject to different definitions, but in a legal context it refers to the heading of a motion or other document filed with a court that typically contains the names of the plaintiff(s) and the defendant(s), the name of the court, the assigned judge, and the case number.
Case captions are governed by the state and local rules of procedure, which vary by jurisdiction. The following is an example of one state's rules governing case captions:
"Case Caption Information: All documents shall contain the following information arranged in the following order, as illustrated by paragraph (e) or (f) of this rule. Individual boxes should separate this case caption information; however, vertical lines are not mandatory.
On the left side:
On the right side: