5 ILCS 160/8

The head of each agency shall cause to be made and preserved records containing adequate and proper documentation of the organization, functions, policies, decisions, procedures, and essential transactions of the agency designed to furnish information to protect the legal and financial rights of the State and of persons directly affected by the agency's activities. This Section shall not be construed to prevent the legal disposal of any records determined by the agency and by the Commission not to have sufficient value to warrant their continued preservation by the State or by the agency concerned.