...Standard & Poor's Ratings Services assigned its '##' long-term rating to San Francisco City & County's series 2015A and 2015B certificates of participation (COPs), which are an appropriation obligation of the city and county. At the same time, Standard & Poor's affirmed its '##+' long-term rating and underlying rating (SPUR) on the city and county's existing general obligation (GO) bonds and its '##' long-term rating and SPUR on the city and county's existing appropriation obligations. Finally, Standard & Poor's affirmed its '###/A-1+' dual rating on obligations that have received joint credit support. The outlook, where applicable, is stable. The city and county's appropriation obligations represent an interest in, or in some cases are secured by, lease payments that the city and county make, as lessee, for the use of capital facilities. Revenue from unlimited ad valorem taxes levied on taxable property within the city and county secures the GO bonds. The San Francisco Board of Supervisors...