quality:correction, structural:expansion
Title IV – Parties

Rule 19 – Compulsory Joinder of Parties – if a person who is not a party to the suit is "necessary" to just adjudication of the action, under the criteria set forth in subsection (a), then upon motion of any party that person shall be made a party, served with suit, and required to participate in the action. If the person cannot be made a party for any reason, such as lack of jurisdiction, inability to be located, etc., then the court uses the criteria in subsection (b) to determine if the absent party is "indispensable". If so, the action must be dismissed.