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.
Official language
When Croatia declared independence (1991) it defined its official language as Croatian, and Serbia likewise defined its official language as Serbian. Bosnia-Herzegovina defined three official languages: Bosnian, Croatian, and Serbian. From the linguistic point of view, the different names refer to national varieties of the same language, which is known under the appellation of Serbo-Croatian. It is said by some that the Bosnian government chose to define three languages to reinforce ethnic differences and keep the country divided.
The language used in Montenegro, traditionally considered a dialect of Serbian, became standardized as the Montenegrin language upon Montenegro's declaration (2006) of independence.