1. Quantitative restrictions: article XI GATT
General prohibition: a cornerstone of the GATT system. The prohibition applies to imports and exports.
Broad concept of quantitative restrictions:
Non-mandatory measures;
De facto restrictions (Argentina – Hides and Leather).
Specific rules for agricultural products and textiles.

2. Quantitative restrictions: article XIII GATT
Quantitative restrictions can be applied in some cases, but they must:
- be non-discriminatory;
- aim at a fair distribution of trade (as close as possible to the shares Member could obtain in the absence of such restrictions: allocation of quotas between all States having a substantial interest);
- be neutral in application and administered in a fair and equitable manner (import-licensing procedures);

3. Other non-tariff barriers: article X GATT
Prompt publication of measures affecting trade in goods; no application before publication.
Establishment of enquiry points.
Uniform, impartial and reasonable administration
Objective and impartial review procedures.

4. Market access barriers to trade in services
No general prohibition. Progressive achievement of liberalisation through rounds of negotation: reciprocity and flexibility for developing countries.
Schedules of specific committments: agreements between States.

5. Other barriers to trade in services
Prompt publication of measures affecting trade in services.
Uniform, impartial and reasonable administration
Limits to domestic regulation (objectivity and transparency, no excessive burdens).
Encouragement of recognition of foreign diplomas and certificates: objective criteria and non-discrimination.