The numbers in parentheses that appear to the right of each industry title are North American Industry Classification System (NAICS) codes that define the economic activities covered by each industry in the Career Guide. These codes are from the 2002 edition of the North American Industry Classification System Manual, a publication of the U. S. Office of Management and Budget that defines and names industries and establishes a structure for relating industries to one another. All statistics on industries produced by the Federal Government are collected in accordance with the NAICS. The NAICS Manual describes the establishment types and goods and services produced in each of the specific industries covered in the Career Guide. Readers interested in obtaining more detailed definitions of the industries in the Career Guide should consult the NAICS Manual, which is available in the reference section of many libraries. The NAICS Manual also may be consulted on the Internet at http://www.census.gov/epcd/www/naics.html. This edition of the Career Guide is the first to be classified according to NAICS. Prior editions classified industries according to the Standard Industrial Classification (SIC), which is no longer being used by Federal statistical programs.