Industry sector
Industry classification or industry taxonomy is a type of economic taxonomy that organizes companies into industrial groupings based on similar production processes, similar products, or similar behavior in financial mark... A wide variety of taxonomies is in use, sponsored by different organizations and based on different criteria.
1The NAICS Index File lists 19745 rubrics beyond the 6 digits which are not assigned codes.
Besides the widely used taxonomies above, there are also more specialized proprietary systems:
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