Section I. The Ordinary Contentious Trial - Title II. The Joinder of the Issue
Can. 1513 §1. The joinder of the issue (contestatio litis) occurs when the terms of the controversy, derived from the petitions and responses of the parties, are defined through a decree of the judge.
§2. The petitions and responses of the parties, besides those in the libellus which introduces the litigation, can be expressed either in a response to the citation or in the oral declarations made before the judge; in more difficult cases, however, the judge must convene the parties to resolve the doubt or doubts which must be answered in the sentence.
§3. The decree of the judge must be communicated to the parties; unless they have already agreed to the terms, the parties can make recourse to the judge within ten days in order to change them; a decree of the judge, however, must resolve the question as promptly as possible (expeditissime).
Can. 1514 Once established, the terms of the controversy cannot be changed validly except by a new decree, for a grave cause, at the request of a party, and after the other parties have been heard and their arguments considered.
Can. 1515 After the issue has been joined, the possessor of the property of another ceases to be in good faith; therefore, if the possessor is sentenced to restore the property, the person must also return the profits made from the day of the joinder and repair any damages.
Can. 1516 After the issue has been joined, the judge is to prescribe a suitable time for the parties to present and complete the proofs.