"In February 1999, the statistical agencies of Canada, Mexico, and the United States launched a joint multi-phase initiative (...) to develop a comprehensive demand-oriented product classification system to complement the new supply-oriented industry classification system introduced in 1997. The industry classification system is known as the North American Industry Classification System (NAICS); the product classification is known as the North American Product Classification System (NAPCS). The long-term objective of NAPCS is to develop a market-oriented, or demand-based, hierarchical classification system for products (goods and services) that (a) is not industry-of-origin based but can be linked to the NAICS industry structure, (b) is consistent across the three NAICS countries, and (c) promotes improvements in the identification and classification of service products across international classification systems, such as the Central Product Classification System of the United Nations. (...)
The products developed under Phases I - III are assembled into 102 product lists that identify and define the significant products produced by about 370 US service industries. These lists include 98 that are at the trilateral level; three at the bilateral level (US and Mexico for NAICS 55-Management of Companies and Enterprises, NAICS 621210-Offices of Dentists, and NAICS 621610-Home Health Care Services); and one at the US-only level (for NAICS 621-2 (except 6212, 6, and 9)-Health Care Services of Physicians, Health Care Practitioners (except Dentists) and Hospitals). Product lines developed from all 102 lists were incorporated into product collection forms developed for the 2007 and 2012 Economic Censuses, and they are being incorporated incrementally into the Service Annual Survey (beginning in 2001)."