Standard & Poor's parent company, McGraw Hill, disclosed in an 8-K on September 26, 2011 that it had received a "Wells Notice" from the Securities and Exchange Commission regarding the rating of a collateralized debt obligation in August of 2007.   The CDO at issue, Delphinus CDO 2007-1, was largely based on subprime mortgage loans.  The Wells Notice indicates that the SEC may initiate litigation seeking civil penalties, disgorgement of fees, and other appropriate equitable relief.  SEC Filing.