20 ILCS 1605/12

The public inspection and copying of the records and data of the Department and the Board shall be generally governed by the provisions of the Freedom of Information Act except that the following shall additionally be exempt from inspection and copying: (i) information privileged against introduction in judicial proceedings; (ii) internal communications of the several agencies; (iii) information concerning secret manufacturing processes or confidential data submitted by any person under this Act; (iv) any creative proposals, scripts, storyboards or other materials prepared by or for the Department, prior to the placement of the materials in the media, if the prior release of the materials would compromise the effectiveness of an advertising campaign.