Form of mark or restricted use of a name that designates that a product comes from a geographically defined area and usually also requires that it meet certain quality standards and be manufactured in a particular way: the best known example are the French system of appellations contrôlées for wines, but it is also applied in various countries to cheese (e.g., reggianno parmagiano), shellfish (Whitby Oysters), spirits (Bourbon Whisky), etc. GDOs are heavily supported by European countries, but are frequently opposed by the major international food companies who wish to market products, e.g., powdered parmesan-style cheese, that are not made in the geographic area or in the specified way.
The United States agreed to recognize GDOs under the TRIPS agreement. The control of most GDOs has been devolved from government to associations of producers, who set standards and requirements. New GDOs are occasionally granted, but it is an under-exploited form of intellectual property. Perversely, some economists oppose GDOs while endorsing trademarks, somehow contriving to rationalize an economic distinction between the two: of course they could be influenced by major international food companies, who value their trademarks much more than they hate GDOs. See Lisbon Agreement for the Protection of Appellations of Origin and their International Registration.