[1] The non-Christian areas were to be collectively represented in the upper house's 12th senatorial district by two senators, both appointed by the Governor-General.
Voters of the more Christianized provinces of Agusan, Bukidnon, Davao and Zamboanga could elect their representative through popular vote by virtue of Article VI, Section 1 of the 1935 Constitution.
[2] In the Muslim-dominated provinces of Cotabato, Lanao and Sulu, however, voter qualifications were more restrictive: the only persons allowed to vote for the province's representative were past and present municipal officials (municipal president, vice-president, municipal councilors); present senators, assembly representatives and 1935 Constitutional Convention delegates; provincial governors and members of provincial boards; and any persons currently residing in the concerned province who held any of the aforementioned positions in the past.
44 on 13 October 1936 to finally give all qualified voters of Lanao (along with Cotabato and Sulu) the right to elect their own representatives through popular vote.
[6] Upon the restoration of the Philippine Commonwealth in 1945 Lanao Province and Dansalan City (later renamed Marawi in 1956[7]) retained their combined pre-war lone congressional district.