^7 A census category recognized as an ethnic group. Most Slavic Muslims (especially in Bosnia, Croatia, Montenegro and Serbia) now opt for Bosniak ethnicity, but some still use the "Muslim" designation. <answer>Bosniak and Muslim</answer> are considered two ethnonyms for a single ethnicity and the terms may even be used interchangeably. However, a small number of people within Bosnia and Herzegovina declare themselves Bosniak but are not necessarily Muslim by faith.
What two groups are considered two ethnonyms for a single ethnicity and the terms may even be used interchangeably?
Bosniak and Muslim