The NAICS and SIC systems are used by the U.S. government
to organize data about the economy.
Many company directories can be searched by one or both of these classification systems,
so finding the code for a particular industry can make researching that industry easier.
This will be especially useful when making custom reports by industry with Mergent Online or ReferenceUSA.
The resources in this section can be searched by SIC and NAICS.