220 ILCS 5/13-509
A telecommunications carrier may negotiate with customers or prospective customers to provide competitive telecommunications service, and in so doing, may offer or agree to provide such service on such terms and for such rates or charges as are reasonable, without regard to any tariffs it may have filed with the Commission or written service offerings posted on the telecommunications carrier's website pursuant to Section 13-501(c) of this Act with respect to such services. Upon request of the Commission, the telecommunications carrier shall submit to the Commission written notice of a list of any such agreements (which list may be filed electronically) within the past year. The notice shall identify the general nature of all such agreements. A copy of each such agreement shall be provided to the Commission within 10 business days after a request for review of the agreement is made by the Commission or is made to the Commission by another telecommunications carrier or by a party to such agreement.
Any agreement or notice entered into or submitted pursuant to the provisions of this Section may, in the Commission's discretion, be accorded proprietary treatment.
220 ILCS 5/13-509