Debt-restructuring agreements are typically undertaken for bank loan debt obligations and involve the buyback and exchange of eligible debt either for financial instruments that are valued at a substantial discount (simple cash buyback) or for new bonds featuring a present value reduction. In some instances, the principal portion of new financial instruments is fully collateralized with zero-coupon bonds issued by the treasury of an industrial country, while interest obligations are also partially secured. DDSR operations are characterized by a “menu approach,” allowing individual creditors to select from among several DDSR options. Under the Brady plan of March 1989, some of these arrangements have been supported by loans from official creditors.