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North American Industry Classification System (NAICS)

The North American Industry Classification System (NAICS, pronounced "nakes") is used to classify business establishments with codes of up to 6 digits. This system was developed to help with comparing industries across the United States, Canada and Mexico. In many of the library's resources, the NAICS code may be used to search for information about an industy. In many resources, the NAICS has replaced or is used alongside the Standard Industrial Classification (SIC) system.

Standard Industrial Classification (SIC)


The Standard Industrial Classification (SIC) system was developed by the United States Government as a way to classify industries. Industries are defined by codes of 2- to 4- digits.

The SIC system is slowly being replaced by the NAICS codes, but some sources continue to use these codes, including Mergent, ReferenceUSA and print sources like Dun & Bradstreet's Key Business Ratios.

To find the SIC code for an industry you're researching try these:

International Standard Industrial Classification

The International Standard Industrial Classification system was developed by the United Nations to classify economic data. The system allows industries to be identified with a 2- to 4- digit code. This system is rarely used by resources held by the library, but occasionally used elsewhere.