On January 15, S&P released its revised methodology and assumptions for projected losses for certain U.S. RMBS prime, subprime, and Alt-A transactions issued from 2005 through 2007.  S&P Methodology. 

On January 13, DBRS updated its rating criteria for U.S. RMBS to provide standardized representations and warranties for newly originated collateral, as well as a standardized set of representations and warranties for seasoned pools.  DBRS Release.  DBRS Methodology. 

On January 15, DBRS released its CMBS rating methodology.  DBRS Methodology.  

Note: Free registration is required for S&P releases and reports.