Slavs
Slavs can be further grouped by religion. Orthodox Christianity is practiced by the majority of Slavs. The Orthodox Slavs include the Belarusians, Bulgarians, Macedonians, Montenegrins, Russians, Serbs, and Ukrainians and are defined by Orthodox customs and Cyrillic script as well as their cultural connection to the Byzantine Empire (Serbs also use Latin script on equal terms). Their second most common religion is Roman Catholicism. The Catholic Slavs include Croats, Czechs, Kashubs, Moravians, Poles, Silesians, Slovaks, Slovenes, and Sorbs and are defined by their Latinate influence and heritage and connection to Western Europe. There are also substantial Protestant and Lutheran minorities especially amongst the West Slavs, such as the historical Bohemian (Czech) Hussites.
Rusyns
Of the estimated 1.2 million people of Rusyn origins, as few as 90,000 individuals have been officially identified as such, in recent national censuses (see infobox above). This is due, in part, to the refusal of some governments to count Rusyns and/or allow them to self-identify on census forms, especially in Ukraine. The ethnic classification of Rusyns as a separate East Slavic ethnicity distinct from Russians, Ukrainians, or Belarusians is, however, politically controversial. The majority of scholarship on the topic considers Rusyns to be an ethnic subgroup of the Ukrainian people. This is disputed by some non-mainstream scholars and some other scholars from Czechia, Slovakia, Canada and America. According to the 2001 Ukrainian Census about a third of Rusyns in Ukraine speak the Ukrainian language, while others stick to their native form.