Categorization Scheme   A collection of categories and subcategories used to describe and locate providers, services, and tModels. A categorization scheme may contain public classifications, such as the North American Industry Classification System (NAICS). It may also contain company-defined categorizations. For example, useful categorization schemes might be constructed around geographical locations, industry segments, or a company's organizational structure. Categorization provides a consistent means by which users may search for providers and services or locate interfaces of a particular type, location, or other attribute.