The ratings on Merrill Lynch Puttable FLOATs/RITES Trust puttable floating option and residual interest tax-exempt receipts series PT-3973, relating to Massachusetts Health And Educational Facilities Authority revenue bonds, Harvard University Issue, series 2005C, have been affirmed due to a review of the amendment memorandum and amendment to the series trust agreement and other relevant documents, from which Standard&Poor's Ratings Services concludes that the amendment will not result in a reduction or withdrawal of the current ratings we have assigned to the captioned P-FLOATs.