District Superintendent of Schools” means an individual employed by a board of education in accordance with Section 10-21.4 of the School Code and shall also include the chief executive officer of a school district in a city with over 500,000 inhabitants.
     “Duly authorized agent” means an individual who has been designated by a Regional or District Superintendent of Schools as their agent for the limited purpose of issuing employment certificates to minors under the age of 16, and may include officials of any public school district, charter school, or any State-recognized, non-public school.
     “Regional Superintendent of Schools” means the chief administrative officer of an educational service region pursuant to Section 3A-2 of the School Code.