220 ILCS 5/6-101

The power of public utilities to issue stocks, stock certificates, bonds, notes and other evidences of indebtedness and to create liens on their property is a special privilege, the right of supervision, regulation, restriction and control of which is and shall continue to be vested in the State, and such power shall be exercised by the Commission hereby created according to the provisions of this Act and under such rules and regulations as the Commission may prescribe.

The Commission shall provide, by serial number or other device to be placed on the face thereof, for the proper and easy identification of such stocks, stock certificates, bonds, notes and other evidences of indebtedness as may be issued by public utilities under the provisions of this article.