Base Offering Circular - Single Family 6 Minimum Denominations Unless otherwise noted in the applicable Offering Circular Supplement, each Trust and MX Trust will issue Regular Securities and MX and/or Modifiable Securities, respectively (other than Securities of Increased Minimum Denomination  Classes),  in  minimum  dollar  denominations  representing  initial  principal  balances  of  $1,000  and integral multiples of $1 in excess of $1,000.  Unless otherwise noted in the applicable Offering Circular Supplement, Residual Securities will be issued in minimum Percentage Interests of 10% and integral multiples of 10%. An Offering Circular Supplement may identify one or more Increased Minimum Denomination Classes, as described in the Offering Circular Supplement. An Increased Minimum Denomination Class is a Class that is deemed to be a suitable investment only for an institutional Accredited Investor that has substantial experience in mortgage-backed securities and that is capable of  understanding,  and  is  able  to  bear,  the  risks  associated  with  an  investment  in  a  Class  such  as  an  Increased Minimum Denomination Class. An   investor   should   not   conclude,   however,   that   Classes   not   designated   as   Increased   Minimum Denomination Classes are suitable for all investors.  No investor should purchase Securities of any Class unless the investor understands, and is able to bear, the risks associated with that Class. Standard Definitions and Abbreviations for Classes and Components Classes  of  Securities  (as  well  as  Components  of  such  Classes)  are  categorized  according  to  “Principal Types,” “Interest Types” and “Other Types.” The chart attached as Appendix I identifies the standard abbreviations for most of these categories.  Definitions of Class Types may be found in Appendix II.  The first column of the chart shows the standard abbreviation for each Class Type.  Each Offering Circular Supplement will identify the category of  Classes  of  the  related  Securities  (and  the  related  Terms  Sheet  will  identify  the  category  of  any  related Components) by means of one or more of these abbreviations. Distributions   Each month, the Trustee for a Series shall calculate the amount of principal and interest distributable on the Securities on the Distribution Date.  The Distribution Amount for each Series (or, if the Series is segregated into Security Groups, for each Security Group) for any Distribution Date for the related Series (or Security Group) will equal the sum of the Principal Distribution Amount (less principal, if any, payable to the Trustee as described in the Offering  Circular  Supplement),  the  Accrual  Amount,  if  any,  and  the  Interest  Distribution  Amount  for  the  related Series (or Security Group). In the case of Trust MBS, the Trustee will determine the amount of principal expected to be received on each  Trust  MBS  during  that  month  on  the  basis  of  Certificate  Factors  for  those  Trust  MBS  for  that  month.    The Trustee will obtain the Certificate Factors from the Information Agent on the seventh Business Day of the month in the  case  of  Ginnie  Mae  I  Certificates  or  on  the  eighth  Business  Day  of  the  month  in  the  case  of  Ginnie  Mae  II Certificates (the “Certificate Factor Date”).  For any Trust MBS for which a Certificate Factor is not available on the Certificate Factor Date, the Trustee will determine a Calculated Certificate Factor. In the case of Underlying Certificates, the Trustee will determine the amount of principal expected to be received on each Underlying Certificate during that month on the basis of Underlying Certificate Factors for those Underlying Certificates  for that  month.  The Trustee  will obtain the Underlying  Certificate Factors in accordance with the related Trust  Agreement.  In the event that an Underlying  Certificate Factor is not available on the date specified in the related Trust Agreement, no amounts in respect of principal for the related Underlying Certificate will be distributable to the related Securities on the following Distribution Date. The  Class  Factors  for  each  Distribution  Date  will  reflect  the  Certificate  Factors  and/or  the  Calculated Certificate Factors for that month (or, in the case of Underlying Certificates, the amount of principal distributable thereon on the preceding Underlying Certificate Payment Date).  Amounts calculated by the Trustee based on the