Slavs
Standardised Slavic languages that have official status in at least one country are: Belarusian, Bosnian, Bulgarian, Croatian, Czech, Macedonian, Montenegrin, Polish, Russian, Serbian, Slovak, Slovene, and Ukrainian.
Serbo-Croatian
On January 15, 1944, the Anti-Fascist Council of the People's Liberation of Yugoslavia (AVNOJ) declared Croatian, Serbian, Slovene, and Macedonian to be equal in the entire territory of Yugoslavia. In 1945 the decision to recognize Croatian and Serbian as separate languages was reversed in favor of a single Serbo-Croatian or Croato-Serbian language. In the Communist-dominated second Yugoslavia, ethnic issues eased to an extent, but the matter of language remained blurred and unresolved.