•   Based on the Class Factors published in the preceding and current months (and Interest Rates), investors in any Class (other than an Accrual Class) can calculate the amount of principal and interest to be distributed to that Class, and investors in an Accrual Class can calculate the total amount of principal to be distributed to (or interest to be added to the Class Principal Balance of) that Class on the Distribution Date in the current month. •   Investors may obtain current Class Factors on e-Access. See "Description of the Securities – Distributions" in the Base Offering Circular. Trading For the sole purpose of facilitating trading and settlement, the Principal Only Classes will be treated as non-delay classes. Termination The Trustee, at its option, may purchase or cause the sale of the Trust Assets and thereby terminate the Trust on any Distribution Date on which the aggregate of the Class Principal Balances of the Securities is less than 1% of the aggregate Original Class Principal Balances of the Securities. The Trustee will terminate the Trust and retire the Securities on any Distribution Date upon the Trustee's determination that the REMIC status of either Trust REMIC has been lost or that a substantial risk exists that this status will be lost for the then current taxable year. Upon any termination of the Trust, the Holder of any outstanding Security (other than a Residual or Notional Class Security) will be entitled to receive that Holder's allocable share of the Class Principal Balance of that Class plus any accrued and unpaid interest thereon at the applicable Interest Rate, and any Holder of any outstanding Notional Class Security will be entitled to receive that Holder's allocable share of any accrued and unpaid interest thereon at the applicable Interest Rate. The Residual Holders will be entitled to their pro rata share of any assets remaining in the Trust REMICs after payment in full of the amounts described in the foregoing sentence. However, any remaining assets are not likely to be significant. Modification and Exchange All or a portion of the Classes of REMIC Securities specified on the inside cover page may be  exchanged  for  a  proportionate  interest  in  the  related  MX  Class  or  Classes  shown  on Schedule I to this Supplement. Similarly, all or a portion of the related MX Class or Classes may be exchanged for proportionate interests in the related Class or Classes of REMIC Securities and, in the case of Combinations 1 through 20 and Combinations 25 through 29, other related MX Classes. This process may occur repeatedly. Each exchange may be effected only in proportions that result in the principal and interest entitlements  of  the  Securities  received  being  equal  to  the  entitlements  of  the  Securities surrendered. In the case of Combinations 1, 2, 3 and 4, the related Classes of REMIC Securities may be exchanged for proportionate interests in various subcombinations of MX Classes. Similarly, all or a portion of these MX Classes may be exchanged for proportionate interests in the related REMIC Securities or in other subcombinations of the MX Classes. Each subcombination may be effected  only  in  proportions  that  result  in  the  principal  and  interest  entitlements  of  the Securities  received  being  equal  to  the  entitlements  of  the  Securities  surrendered.  See  the example  under  "Description  of  the  Securities – Modification  and  Exchange"  in  the  Base Offering Circular. S-16