ORS 419B.863: Pleadings; captions.

(1) Every petition, answer, motion or other paper must contain a caption setting forth the name of the court, the title of the action and the register number of the case.

      (2) When a party does not know the name of another party and alleges that lack of knowledge in a petition, answer, motion or other paper, the other party may be designated by any name. When the other party’s true name is discovered, the process and all petitions, answers, motions, other papers and proceedings in the case may be amended by substituting the true name.