Base Offering Circular – Multifamily 63 Callable Series...........................  A Series of Ginnie Mae Guaranteed Callable Pass-Through Securities issued pursuant to a Trust Agreement and having the numerical or other designation specified in the related Trust Agreement. Callable Standard Trust Provisions.................................. With respect to each Callable Trust, the Standard Trust Provisions in effect as of the date of the related trust agreement and incorporated by reference therein. Callable Trust............................  A trust created pursuant to a trust agreement for the purpose of issuing Call and Callable Class Securities. Certificate Factor.......................  With respect to each Trust MBS or Underlying Callable Security and each Certificate Factor Date, the factor for such date. Certificate Factor Date ..............  With respect to each Distribution Date and any Ginnie Mae Multifamily Certificate, the seventh Business Day of the month in which such Distribution Date occurs.  With respect to each Distribution Date and any Underlying Callable Security, the Business Day during the month in which such Distribution Date occurs on which the Certificate Factor therefor is published. Certificate Guaranty Agreement................................. With respect to each Ginnie Mae Multifamily Certificate, an agreement under which, among other things, (a) the related Ginnie Mae Issuer has agreed to advance its own funds in order to make timely payments on the Ginnie Mae Multifamily Certificate, even if the amounts received on the underlying Mortgage Loans are less than required to make these payments, and (b) Ginnie Mae has agreed to guarantee payments on the Ginnie Mae Multifamily Certificates. Certificate Rate..........................  For any Distribution Date and as to any Trust MBS, the per annum interest rate payable on the Trust MBS on the applicable Ginnie Mae Certificate Payment Date.  For any Distribution Date and as to any Underlying Certificate, the per annum interest rate payable on such Underlying Certificate on the applicable Underlying Certificate Payment Date.  For any Distribution Date and as to any Underlying Callable Security, the per annum interest rate payable on such Underlying Callable Security on the applicable Ginnie Mae Certificate Payment Date. Certificated Security..................  With respect to each Trust or MX Trust, as applicable, a Security represented by one or more physical certificates that is not a Book-Entry Security.