Domestic industry definition determines which producers qualify for countervailing duty investigations and exclusions. Definitions set the scope of countervailing duty investigations: Domestic industry means domestic producers collectively manufacturing the like article or those whose output forms a major proportion of domestic production, excluding producers related to exporters/importers; separate competitive markets may be treated as distinct industries in exceptional circumstances. Producers are related where control exists. Interested party, like article, period of investigation, provisional duty, and specified country are defined for investigative and procedural purposes, with subsequent notes recording amendments to these definitions.