(1) Judicial review proceedings are to be commenced by summons.
(2) If a decision to be reviewed arose in the course of a dispute between parties, each party who is interested in maintaining the decision must be joined as a defendant.
(3) If the proceedings seek to prohibit, injunct or mandate a step that has not been taken, each body or person who may be directly affected by the relief sought must be joined as a defendant.
(4) The body or person responsible for a decision to be reviewed must be joined as a defendant, but not as the first defendant unless there is no other defendant.