An indenture may include a clause relating to the bonds issued pursuant to the indenture requiring the regents to pay and discharge, or cause to be paid and discharged, all lawful claims for labor, materials, and supplies or other charges which, if unpaid, might become a lien or charge upon the revenues, or any part of the revenues, of any project acquired, constructed, or completed from the proceeds of the sale of the bonds, or upon any physicial properties, or which might impair the security of the bonds.