Any policy that interferes with exports or imports other than a simple tariff, prominently including quotas and VERs.

any government action other than a tariff that reduces imports, such as a quota or a standard.

Any action other than a tariff that restricts international trade. (p. 466)

Government measures, such as import monitoring systems and variable levies, other than tariffs that restrict imports or that have the potential for restricting international trade.

A regulation, other than a tariff, that inhibits free movement of imports or exports. A particular "nontariff barrier" may be legitimate or worthwhile, even if it is penalized under international trade agreements.

A border measure, regulation, or other government action other than a tariff used by governments to restrict imports from, and exports to, other countries. Examples: embargoes, import quotas, quantitative restriction (quotas), licensing, domestic support programs, labeling and health standards, technical barriers to trade, and exclusive business practices.

A nontariff barrier is any action other than a tariff that restricts international trade.