Proto-Philippine  The Proto-Philippine language is a reconstructed ancestral proto-language of the Philippine languages, a proposed subgroup of the Austronesian languages which includes all languages within the Philippines (except for the Sama–Bajaw languages) as well as those within the northern portions of Sulawesi in Indonesia. Proto-Philippine is not directly attested to in any written work, but linguistic reconstruction by the comparative method has found regular similarities among languages that cannot be explained by coincidence or word-borrowing. There have been three initial proposals in delineating the southern boundaries of the Philippine group: Northern Borneo in Malaysia, southern Philippines (encompassing southern Luzon all the way to Mindanao and the Sulu Sea area), and northern Sulawesi in Indonesia. The earliest boundary was proposed by Esser (1938) between the Gorontalo languages and the Tomini languages of Sulawesi. While it was later found decades after (Himmelmann, 1990) that there are shared innovations between Philippine and Tomini languages, there are still uncertainties as to whether the latter do validly form one genetic group, or should be relegated as a mere geographic unit. Meanwhile, Charles (1974) in particular proposed that languages in Sabah and of northern Sarawak are descendants of this Proto-Philippines, which has subsequently garnered counter-evidences (Blust, 1974; Reid, 1982; Zorc, 1986). Lastly, there have been several proposals establishing southern Philippines as the boundary (Thomas & Healey, 1962; Dyen, 1965; Zorc, 1977; 1986) with the "Macro Meso-Philippine" and "Sangiric" as two primary branches. Walton (1979) and McFarland (1980) included the Sama-Bajau group as the third branch, but such has been later disputed as entirely separate directly under Malayo-Polynesian. Due to issues in the validity of a Philippine genetic group, and thus the existence of an ancestral Proto-Philippines language, most of its features particularly its phonology remain as proposals. Llamzon's (1975) proposed phonology of Proto-Philippines was derived from earlier reconstructions of Dempwolff's (1934-1938) works by Dyen (1947; 1951; 1953a; 1953b; 1953c). Used in this reconstruction were nine languages—Tagalog, Cebuano, Hiligaynon, Waray, Bikol (Central?), Ilokano, Ibanag, Ifugao, and Kankanaey—with the rationale that the aforementioned have "relatively better structural description and vocabularies" than other related and geographically contiguous languages at that time.