Croatian language
Standard Croatian is the official language of the Republic of Croatia and, along with Standard Bosnian and Standard Serbian, one of three official languages of Bosnia and Herzegovina. It is also official in the regions of Burgenland (Austria), Molise (Italy) and Vojvodina (Serbia). Additionally, it has co-official status alongside Romanian in the communes of Carașova and Lupac, Romania. In these localities, Croats or Krashovani make up the majority of the population, and education, signage and access to public administration and the justice system are provided in Croatian, alongside Romanian.
Serbo-Croatian
The topic of language for writers from Dalmatia and Dubrovnik prior to the 19th century made a distinction only between speakers of Italian or Slavic, since those were the two main groups that inhabited Dalmatian city-states at that time. Whether someone spoke Croatian or Serbian was not an important distinction then, as the two languages were not distinguished by most speakers. This has been used as an argument to state that Croatian literature Croatian per se, but also includes Serbian and other languages that are part of Serbo-Croatian, These facts undermine the Croatian language proponents' argument that modern-day Croatian is based on a language called Old Croatian.