Standard&Poor's Ratings Services assigned its 'A' rating to Orange County, Fla.'s tourist development tax refunding bonds, series 2006, and affirmed its 'A' underlying rating (SPUR) on the county's outstanding tourist development revenue bonds. The 'A' rating reflects the county's: Strong, underlying economic base, anchored by the city of Orlando, a major tourist destination; Good debt-service coverage of future maximum annual debt service; Strong pledged revenue growth; and Adequate legal provisions. Offsetting factors include a vulnerability of tourist development tax (TDT) revenues to downturns in both national and global economic conditions that impact tourism and travel. Proceeds of the bonds will be used to refund a portion of the county's outstanding TDT revenues bonds, series 2002. The bonds are