334-Computer and Electronic Product Manufacturing
- 334111: Electronic Computer Manufacturing

- 334112: Computer Storage Device Manufacturing

- 224113: Computer Terminal Manufacturing
- 334119: Other Computer Peripheral Equipment Manufacturing

- 334210: Telephone Apparatus Manufacturing  

- 334220: Radio and Television Broadcasting and Wireless

                  Communications Equipment Manufacturing

423-Durable Goods
- 423430: Computer and Computer Peripheral Equipment and
                  Software Merchant Wholesalers
- 423690: Other Electronic Parts and Equipment Merchant
                  Wholesalers

425-Wholesale Electronic Markets and Agents and Brokers
- 425110: Business to Business Electronic Markets

517-Telecommunications
- 517110: Wired Telecommunications Carriers
- 517210: Wireless Telecommunications Carriers (except
                  satellite)
- 517911: Telecommunications Resellers

541-Professional, Scientific and Technical Services
-541519: Other Computer Related Services
 

561-Administrative and Support Services
-561210: Facilities Support Services (Note 1)
-561621 Security Systems Services