Use the proceeds of any Loans or Letters of Credit for any purpose except as contemplated by Section 6.16. Any proceeds of Loans or Letters of Credit used for the purposes contemplated by Section 6.16 shall not be used, whether directly or indirectly, and whether immediately, incidentally or ultimately, to purchase or carry margin stock (within the meaning of Regulation U of the Board) or to extend credit to others for the purpose of purchasing or carrying margin stock or to refund indebtedness originally incurred for such purpose.