In accordance with Illinois law, if the Property contains one (1) to four (4) dwelling units, the Seller must complete the Property Disclosure. A listing agreement is a legally binding contract between a homeowner and the real estate agent or broker who will be listing the property for sale.Here to walk you through listing contracts like the contract 101. Selling your home and not sure what a listing agreement is? Our comprehensive guide will help you navigate this crucial contract with ease. Fair Housing Act IT IS ILLEGAL FOR EITHER THE SELLER OR THE BROKER TO REFUSE TO DISPLAY, LIST, LEASE OR SELL, OR REFUSE TO NEGOTIATE. You and your Realtor will likely review this contract in detail and fill it out together. Vacant Land Contract Training. REALTORS to facilitate any arbitration. A For Sale By Owner contract Illinois must include: 1.