From the longer Wikipedia page [1]
The Autonomous Region in Muslim Mindanao (Filipino: Awtonomong Rehiyon sa Muslim Mindanao, Arabic: الحكم الذاتي الاقليمي لمسلمي مندناو Al-ḥukm adh-dhātiyy al-'aqlīmiyy limuslimiyy mindanāu; abbreviated ARMM) is an autonomous region of the Philippines, located in the Mindanao island group of the Philippines, that consists of five predominantly Muslim provinces: Basilan (except Isabela City), Lanao del Sur, Maguindanao, Sulu and Tawi-Tawi. It is the only region that has its own government. The region's de facto seat of government is Cotabato City, although this self-governing city is outside of its jurisdiction.
The ARMM previously included the province of Shariff Kabunsuan until 16 July 2008, when Shariff Kabunsuan ceased to exist as a province after the Supreme Court of the Philippines declared the "Muslim Mindanao Autonomy Act 201", which created it, unconstitutional in Sema vs. COMELEC.
On 7 October 2012, President Benigno Aquino III said that the government aimed to have peace in the autonomous region and that it will become known as Bangsamoro Autonomous Region,a compound of bangsa (nation) and Moro