Whenever the Postal Service determines to request that the Commission issue an advisory opinion on a proposed change in the nature of postal services subject to this subpart, the Postal Service shall file with the Commission a formal request for such an opinion in accordance with the requirements of §§ 3001.9 to 3001.11 and 3001.74. Such request shall be filed not less than 90 days in advance of the date on which the Postal Service proposes to make effective the change in the nature of postal services involved. Within 5 days after the Postal Service has filed a formal request for a recommended decision in accordance with this subsection, the Secretary shall lodge a notice thereof with the Director of the Federal Register for publication in the