The Administrator may make and enforce such reasonable rules as are necessary to administer and enforce this Act. Such rules and regulations shall conform to and comply with “The Illinois Administrative Procedure Act”, approved September 22, 1975, as amended. The Administrator may in his discretion honor requests for interpretive opinions. The Administrator shall maintain a complete collection of his interpretive opinions which is properly indexed, a copy of which shall be made available to any person upon request and payment of a reasonable fee to be determined by the Administrator.