on the Regular Securities (as described in "Yield, Maturity and Prepayment Considerations" in this Supplement) is as follows: Security Group PSA 1 225% 2 175% 3 150% 4 150% 5 225% 6 251% 7 150% 8 150% 9 150% 10 150% 11 150% 12 150% 13 150% In the case of the Floating Rate Classes, the constant value of LIBOR to be used for these determinations  is  1.10%.  No  representation  is  made,  however,  about  the  rate  at  which prepayments on the Mortgage Loans underlying any Group of Trust Assets actually will occur or the level of LIBOR at any time after the date of this Supplement. See "Certain Federal Income Tax Consequences" in the Base Offering Circular. The  Regular  Securities  generally  will  be  treated  as  "regular  interests"  in  a  REMIC  for domestic building and loan associations, "permitted assets" for financial asset securitization investment  trusts  ("FASITs"),  and  "real  estate  assets"  for  real  estate  investment  trusts ("REITs") as described in "Certain Federal Income Tax Consequences" in the Base Offering Circular. Similarly, interest on the Regular Securities will be considered "interest on obliga- tions secured by mortgages on real property" for REITs. Residual Securities The Class RR Securities will represent the beneficial ownership of the Residual Interest in the Pooling REMIC and the beneficial ownership of the Residual Interest in the Issuing REMIC. The Residual Securities, i.e., the Class RR  Securities, generally will be treated as "residual interests" in a REMIC for domestic building and loan associations and as "real estate assets" for REITs,  as  described  in  "Certain  Federal  Income  Tax  Consequences"  in  the  Base  Offering Circular, but will not be treated as debt for federal income tax purposes. Instead, the Holders of the Residual Securities will be required to report, and will be taxed on, their pro rata shares of the taxable income or loss of the Trust REMICs, and these requirements will continue until there  are  no  outstanding  regular  interests  in  the  respective  Trust  REMICs.  Thus,  Residual Holders will have taxable income attributable to the Residual Securities even though they will not receive principal or interest distributions with respect to the Residual Securities, which could result in a negative after-tax return for the Residual Holders. It is not expected that the Pooling  REMIC  will  have  a  substantial  amount  of  taxable  income  or  loss  in  any  period. However, even though the Holders of the Class RR Securities are not entitled to any stated principal  or  interest  payments  on  the  Class  RR  Securities,  the  Issuing  REMIC  may  have substantial taxable income in certain periods, and offsetting tax losses may not occur until much S-46