All net funds derived from auxiliary enterprises in any institution under the supervision of the State Board for Technical and Comprehensive Education shall be expended by the institution subject to the following limitations: up to twenty percent of the net funds/or $1,000 whichever is greater may be expended specifically for promotional use and at least eighty percent of the net funds shall be expended for the institution’s operational expenses. Provided, further, That promotional expenditures shall be in keeping with policies and guidelines developed by the State Board for Technical and Comprehensive Education.