According to some Filipinologists (people who specialize in the study of Filipino as a language), the main reason that Filipino is distinct from Tagalog is that in Filipino, there is a presence of vocabulary coming from other Philippine languages, such as Cebuano (such as "bana" - husband), Hiligaynon (such as "buang" - insane) and Ilocano (such as "ading" - little brother). They also maintain that the term Tagalog is the language of the Katagalugan or the Tagalog Region and puristic in a sense. It lacks certain phonemes like /f/ and /v/, which makes it incapable of producing some indigenous proper nouns "Ifugao" and "Ivatan". Curiously, proponents of language secessionism are unable to account for the glaring absence of long vowel, phonemic in Tausug, in Filipino phonology or for the absence of a schwa. Arguments for secessionism generally ignore the fact that the various languages of the Philippines have divergent phonologies.