It is the policy of the state of Minnesota that public school education shall be free and no pupil shall be denied an education because of economic inability to furnish educational books and supplies necessary to complete educational requirements necessary for graduation. Any practice leading to suspension, coercion, exclusion, withholding of grades or diplomas, or discriminatory action based upon nonpayment of fees denies pupils their right to equal protection and entitled privileges. It is recognized that school boards do have the right to accept voluntary contributions, to make certain charges and to establish fees in areas considered extra curricular, noncurricular or supplementary to the requirements for the successful completion of a class or educational program, and to waive those fees under certain circumstances. No public school board may require, except as authorized by sections 123B.36 and 123B.38, the payment of fees.