Art. 644 Party plaintiff who refuses or fails to sue

If someone needs to be part of a lawsuit as a plaintiff, but they won't join the case on their own, the court can still bring them in. In this situation, they get added as a defendant instead. This forces them to speak up about their rights and interests in the case.

If that person doesn't take the chance to assert their rights during the lawsuit, they can lose the ability to bring up those rights later. In other words, they can't sit on the sidelines and then try to raise the same issue in a separate case afterward. This rule pushes everyone with a stake in the matter to deal with it in one lawsuit, so the same dispute doesn't have to be settled twice.