21.09.1 Where numerous persons have the same interest in any proceeding the proceeding may be commenced and, unless the Court or a Justice otherwise orders, may be continued by or against any one or more persons having the same interest as representing some or all of them.
21.09.2 A judgment given or order made in a proceeding to which rule 21.09.1 applies shall bind the parties and those whom the parties represent.
21.09.3 A judgment or order shall not be enforced against a person who is not a party except by leave of the Court or a Justice.
21.09.4 An application for leave under rule 21.09.3 must:
(b) be served personally on the person against whom enforcement of the judgment or order is sought.