Nazi policy stressed the superiority of the Nordic race, a sub-race of the white European population defined by the measurement of the size and proportions of the human body models of racial difference. From 1940 the Nazis in General Government (occupied Poland) divided the population into different groups. Each group had different rights, food rations, allowed strips in the cities, separated residential areas, special schooling systems, public transportation and restricted restaurants. Later adapted in all Nazi-occupied countries by 1942, the Germanization program used the racial caste system of reserving certain rights to one group and barred privileges to another. Ethnic Poles were believed by Hitler to be "biologically inferior race" that could never be educated or elevated through Germanization. In 1940, Hitler approved of a plan regarding the Germanization of the Protectorate of Bohemia and Moravia, he estimated around half of the Czech population were suitable for Germanization but made clear that the "mongoloid" types and Czech intelligentsia were not allowed to be Germanized.