Currency of the country (called the 'primary environment' ) in which a firm a conducts its business activities and generates most or all of its income and expenses. It may or may not be the currency in which it presents its financial statements, which is called reporting currency or presentation currency. For U.S. firms operating in foreign countries, the reporting requirements are governed by the rules of the Financial Accounting Standards Board, particularly statements 8 and 52 (FASB No. 8 and FASB No. 52).