number one in all of America; best in all of America
US Open (esp. tennis and golf championships)
National Science Foundation (USA); NSF
Amateur Athletic Union; AAU
National Rifle Association of America; NRA
National Organization for Women; NOW
National Information Infrastructure; NII
National Nutritional Foods Association; NNFA
National Nutritional Foods Association; NNFA
Consumer Electronics Association; CEA
National Academy of Sciences (US)
National Bureau of Economic Research
(former) National Association of Purchasing Management (USA); NAPM
National Association of Home Builders
National Association of Securities Dealers
National Association of Manufacturers; NAM
National Collegiate Athletic Association
National Railroad Passenger Corporation
Baseball Writers' Association of America
National Wildlife Federation
American Forest and Paper Association
National Association of Securities Dealers; NASD
National Society of Film Critics Awards