This excerpt taken from the STI 10-K filed Feb 20, 2008.
Note 11 Securitization Activity and MSRs
The Company sells and securitizes residential mortgage loans, student loans, commercial loans, including commercial mortgage loans, as well as debt securities. Interests that continue to be held by the Company (interests held) in securitized assets, including debt securities, are recorded as securities available for sale or trading assets at their allocated carrying amounts based on the relative fair value at time of securitization. Interests held are subsequently carried at fair value. For subordinated and other residual interests for which there is no quoted market price, fair value is generally estimated based on the present value of expected cash flows, calculated using managements best estimates of key assumptions, including credit losses, loan repayment speeds and discount rates commensurate with the risks involved. Gains or losses upon securitization as well as servicing fees and collateral management fees are recorded in noninterest income.