199—4.6 (17A) Service and filing of petitions and other papers.
	 4.6(1) When service required. Except where otherwise provided by law, every petition for declaratory order, petition for intervention, brief, or other paper filed in a proceeding for a declaratory order shall be served upon each of the parties of record to the proceeding and on any persons who, based upon a reasonable investigation, would be a necessary party to the proceeding under applicable substantive law, simultaneously with their filing. The party filing a document is responsible for service on all parties and other required persons.
	 4.6(2) Filing—when required. All petitions for declaratory orders, petitions for intervention, briefs, or other papers filed in a proceeding for a declaratory order shall be filed with the Executive Secretary, 350 Maple Street, Des Moines, Iowa 50319-0069. All petitions, briefs, or other papers that are required to be served upon a party shall be filed simultaneously with the utilities board.
	 4.6(3) Method of service, time of filing, and proof of mailing. Method of service, time of filing, and proof of mailing shall be as provided by 199—subrule 7.6(1).