The numbers in parentheses that appear at the bottom of most occupational statements are from the Occupational Information Network (O*NET), which has replaced the Dictionary of Occupational Titles (D.O.T.). Like the D.O.T. in the past, the O*NET is used by State employment service offices to classify applicants and job openings, and by some career information centers and libraries to file occupational information.

An index beginning on page 530 of the print edition of the Handbook cross-references O*NET codes to occupations covered in the Handbook. The O*NET is also cross-referenced to the revised 1998 Standard Occupational Classification (SOC). All Federal Government agencies that collect occupational data are expected to adopt the new SOC over the next few years.