Modification and Exchange: If you own exchangeable Securities you will be able, upon notice and payment of an exchange fee, to exchange them for a proportionate interest in the related Securities shown on Schedule I to this Supplement. See "Description of the Securi- ties – Modification and Exchange" in this Supplement. Increased Minimum Denomination Classes: Each Class that constitutes an Interest Only Class. See "Description of the Securities – Form of Securities" in this Supplement. Interest Rates: The Interest Rates are shown on the inside cover page of this Supplement or on Schedule I to this Supplement. Allocation  of  Principal: On  each  Distribution  Date  for  a  Security  Group,  the  following distributions will be made to the related Securities: SECURITY GROUP 1 A percentage of the Group 1 Principal Distribution Amount will be applied to the Trustee Fee, and the remainder of the Group 1 Principal Distribution Amount (the "Group 1 Adjusted Principal Distribution Amount") will be allocated in the following order of priority: 1.  Sequentially, to PA, PB, PC and PD, in that order, until reduced to their Aggregate Scheduled Principal Balance for that Distribution Date 2.  Sequentially, to YA, YB, YC and YD, in that order, until reduced to their Aggregate Scheduled Principal Balance for that Distribution Date 3.  Sequentially, to GA, GB, GC, GD and GE, in that order, until retired 4.  Sequentially, to YA, YB, YC and YD, in that order, without regard to their Aggregate Scheduled Principal Balances, until retired 5.  Sequentially to PA, PB, PC and PD, in that order, without regard to their Aggregate Scheduled Principal Balances, until retired SECURITY GROUP 2 The Group 2 Principal Distribution Amount will be allocated, sequentially, to A and B, in that order, until retired Scheduled Principal Balances: The Aggregate Scheduled Principal Balances for the Classes listed  below  are  included  in  Schedule  II  to  this  Supplement.  They  were  calculated  using, among other things, the following Structuring Ranges: Class Structuring Ranges PA, PB, PC and PD (in the aggregate)  .......................... 100% PSA through 250% PSA YA, YB, YC and YD (in the aggregate) .......................... 108% PSA through 200% PSA B-18