Autonomous prefectures are one type of autonomous areas of China, existing at the prefectural level, with either ethnic minorities forming over 50% of the population or being the historic home of significant minorities. All autonomous prefectures are mostly dominated, in population, by the Han Chinese. The official name of an autonomous prefecture includes the most dominant minority in that region, sometimes two, rarely three. For example, a Kazakh (Kazak in official naming system) prefecture may be called Kazak Zizhizhou. Like all other prefectural level divisions, autonomous prefectures are divided into county level divisions. There is one exception: Ili Kazak Autonomous Prefecture contains two prefectures of its own. Under the Constitution of the People's Republic of China, autonomous prefectures cannot be abolished.