Sec. 720-9.1. Bill inserts

(a) Each public utility, other than a waterworks corporation, billing other than by postcard and serving more than 25,000 customers, shall furnish to its customers a narrative description of the essential elements affecting them of each proposed major rate change, by bill inserts to be included with the next utility bills mailed commencing not later than seven days after the rates are filed.

(b) The narrative description shall include the following: The commission may approve, modify or reject any or all of the proposed tariff changes. Among other things, the commission's determination may require revisions of the proposed amount of the increases applicable to particular classifications of service, or changes in rates applicable to those classifications for which no increase is proposed by the company.

(c) Applications for waiver of the requirements for such mailing may be granted upon a sufficient showing.