225 ILCS 710/7.01

Every operator of any mine shall in writing designate an authorized representative upon whom all reports, notices, warnings or other documents may be served under the provisions of this Act, and a copy of such authorization shall be filed with the Director of the Office of Mines and Minerals and shall remain in full force until revoked by an instrument in writing filed with such Director. Every operator or his or her duly authorized representative shall sign by name and title on a dated line for each report, notice or warning issued and delivered to him or her by the Inspector of Mines.