In some eastern states, formerly used synonym for the grape varieties Blaufränkisch (Oporto), Blue Portuguese (Oporto, Oporto Kék), Early Blue Portuguese (Oportorebe), Grey Portuguese (Oporto,Oporto Szuerke) and Green Portuguese (Oporto, Oporto Fehér). However, the use of this name has been prohibited since these countries joined the EU in order to prevent confusion with the protected designation of origin Porto for port wine. However, Oporto is also a synonym for the two varieties Oporto d'Amerique and Teinturier du Cher.
Serious sources on the internet are rare - and Wine lexicon from wein.plus is one such source. When researching for my articles, I regularly consult the wein.plus encyclopaedia. There I get reliable and detailed information.
Thomas Götz
Weinberater, Weinblogger und Journalist; Schwendi