GAO reviewed domestic air carriers' watch-list-matching processes. GAO examined (1) the watch-list-matching requirements air carriers must follow that have been established by TSA, and (2) the extent to which TSA has assessed air carriers' compliance with these requirements. GAO reviewed TSA's security directives, internal guidance used by TSA's inspectors to assess air carriers' compliance with requirements, and inspection results, as well as interviewed staff from 14 of 95 domestic air carriers (selected to reflect a range in operational sizes). This report is the public version of a restricted report (GAO-08-453SU) issued in July 2008.