Section 10. Pledging credit.

Neither the state nor any county, school district, municipality, special district, or agency of any of them, shall become a joint owner with, or stockholder of, or give, lend or use its taxing power or credit to aid any corporation, association, partnership or person; but this shall not prohibit laws authorizing:
(a) the investment of public trust funds;
(b) the investment of other public funds in obligations of, or insured by, the United States or any of its instrumentalities;
(c) the issuance and sale by any county, municipality, special district or other local governmental body of (1) revenue bonds to finance or refinance the cost of capital projects for airports or port facilities, or (2) revenue bonds to finance or refinance the cost of capital projects for industrial or manufacturing plants to the extent that the interest thereon is exempt from income taxes under the then existing laws of the United States, when, in either case, the revenue bonds are payable solely from revenue derived from the sale, operation or leasing of the projects. If any project so financed, or any part thereof, is occupied or operated by any private corporation, association, partnership or person pursuant to contract or lease with the issuing body, the property interest created by such contract or lease shall be subject to taxation to the same extent as other privately owned property.
(d) a municipality, county, special district, or agency of any of them, being a joint owner of, giving, or lending or using its taxing power or credit for the joint ownership, construction and operation of electrical energy generating or transmission facilities with any corporation, association, partnership or person.