[1] Cotabato had been admitted as a special province under the Department of Mindanao and Sulu since 1914 but was only previously represented through a multi-member delegation appointed by the Governor General covering all of Mindanao territory except Misamis and Surigao beginning in 1916.
[3] The Spanish district was earlier represented in the Malolos Congress of the nascent First Philippine Republic by two delegates from Luzon.
[4] Datu Balabaran Sinsúat of the Nacionalista Demócrata Pro-Independencia was elected as the single-member district's first representative in 1935 by a select group of electors composed of municipal and municipal district presidents, vice-presidents and councilors, among others.
44 in 1936 which removed the restrictions on qualified voters in the former Bureau of Non-Christian Tribes-designated jurisdiction.
[7] Cotabato was also represented as a plural member constituency in the Second Republic National Assembly during the Pacific War.