Chakavian
Chakavian in its actual use is the least spoken Serbo-Croatian dialect, being spoken only by 12% Croats. It is now mostly reduced in southwestern Croatia along the eastern Adriatic: Adriatic islands, and sporadically in the mainland coast, with rare inland enclaves up to central Croatia, and minor enclaves in Austria and Montenegro. All areas of old contacts with Romance languages.
Constitution of Croatia
Article 12 states that the official language is Croatian in the Latin script and that in some areas, together with the Croatian language and Latin script, other languages, such as Cyrillic or any other legal language can be used.