225 ILCS 440/3.20

"Municipal network sign" means an official sign or a sign that: (1) is located on property owned or controlled by a local government that has a population of 2,000,000 or more and that has adopted zoning regulations consistent with this Act; (2) is controlled under the direction of the local government; (3) complies with zoning regulations consistent with this Act; (4) is placed within a business area as defined in Section 3.12 of this Act; (5) is used to communicate emergency, public, and commercial information; and (6) is consistent with the intent of this Act and with customary use of the local government as to the sign's installation and operation, including the size, lighting, and spacing of signs.