not a national cost of funds, it may not behave as would a nationally based index. In addition, the movement of COFI, as compared to other indices tied to specific interest rates, may be affected by changes instituted by the FHLB of San Francisco in the method used to calculate COFI. Investors can order an informational brochure explaining COFI by writing or calling the FHLB  of  San  Francisco's  Marketing  Department,  P.O.  Box  7948,  San  Francisco,  California 94120, phone 415/616-2610. The current level of COFI can be obtained by calling the FHLB of San Francisco at 415/616-2600. If the FHLB of San Francisco fails to publish COFI for a period of 65 calendar days (an event that will constitute an "Alternative Rate Event"), then the Trustee (or its agent) will calculate the Interest Rates of the COFI Classes for the subsequent Accrual Periods by using, in place of COFI, (i) the replacement index, if any, that the FHLB of San Francisco publishes or designates or (ii) if the FHLB of San Francisco does not publish or designate a replacement index, an alternative index selected by the Trustee (or its agent) and approved by Ginnie Mae that has performed, or that the Trustee expects to perform, in a manner substantially similar to COFI. At the time that the Trustee first selects an alternative index, the Trustee will determine the average number of basis points, if any, by which the alternative index differed from COFI for whatever period the Trustee, in its sole discretion, reasonably determines to reflect fairly the long-term difference between COFI and the alternative index, and will adjust the alternative index by that average. The Trustee (or its agent) will select a particular index as the alternative index only if it receives an Opinion of Counsel that the selection of that index will not cause the related Trust REMIC or Trust REMICs to lose their status as REMICs for federal income tax purposes. If at any time after the occurrence of an Alternative Rate Event, the FHLB of San Francisco resumes  publication  of  COFI,  the  Interest  Rates  of  the  COFI  Classes  for  each  subsequent Accrual Period will be calculated by reference to COFI. Determination of the Treasury Index Unless otherwise provided in the applicable Offering Circular Supplement, the Trustee (or its agent) will calculate the Interest Rates of Treasury Index Classes for each Accrual Period (after the first) on the Floating Rate Adjustment Date. On each Floating Rate Adjustment Date, the Trustee will determine the applicable Treasury Index, which will be either (i) the weekly average yield, expressed as a per annum rate, on U.S. Treasury securities adjusted to a constant maturity of one, three, five, seven or ten years or to some other constant maturity (as specified in the applicable Supplement) as published by the Federal Reserve Board in the most recent edition of Federal Reserve Board Statistical Release No. H.15 (519) that is available to the Trustee or (ii) the weekly auction average (investment) yield, expressed as a per annum rate, on three-month or six-month U.S. Treasury bills that is available on the Treasury Public Affairs Information Line, an automated telephone system. The Statistical Release No. H.15 (519) is published by the Federal Reserve on Monday or Tuesday of each week. Investors can order it from the Publications Department at the Board of Governors of the Federal Reserve System, 21st and C Streets, N.W., M.S. 138, Washington, D.C. 20551. The Trustee will consider a new value for the Treasury Index to have been available on the day following the date that Statistical Release No. H.15 (519) is released by the Federal Reserve Board or the Public Debt News is placed on the Treasury Public Affairs Public Information Line and available to the public. The applicable auction average (investment) yield for a given week is the yield resulting from the auction of three-month or six-month U.S. Treasury bills held the preceding week. The weekly average yield reflects the average yields of the five calendar days ending on Friday of the previous week. Yields on Treasury securities at "constant maturity" are estimated from the Treasury's daily yield curve. This curve, which relates the yield on a security to its time to maturity, is based on the closing market bid yields on actively traded Treasury securities in the 9