Protected Geographical Indication (PGI), and Traditional Specialties Guaranteed (TSG). PDOs cover "agricultural products and foodstuffs which are produced, processed and prepared in a given geographical area using recognized know-how." PGIs are similar except that "at least one of the
Common-Law Geographical Indications. Geographical indications also are protected through common law trademark law without being registered by the USPTO. For example, the TTAB has held that "COGNAC" is protected as a common-law (unregistered) certification mark in the United States. Institut National Des Appellations v.