(a) Whenever the Postal Service proposes material changes to a product description in the Mail Classification Schedule, no later than 30 days prior to implementing the proposed changes, it shall submit to the Commission a request to change the product description in the Mail Classification Schedule.

(b) The request shall:

(1) Include a copy of the applicable sections of the Mail Classification Schedule and the proposed changes therein in legislative format; and

(2) Provide all supporting justification for the changes upon which the Postal Service proposes to rely.