During Taiwan under Japanese rule (1895–1945), the use of Pe̍h-ōe-jī was suppressed and it faced further countermeasures during the Kuomintangmartial law period (1947–1987). In Fujian, use declined after the establishment of the People's Republic of China (1949) and in the early 21st century the system was not in general use there. Taiwanese Christians, non-native learners of Southern Min, and native-speaker enthusiasts in Taiwan are among those that continue to use Pe̍h-ōe-jī. Full native computer support was developed in 2004, and users can now call on fonts, input methods, and extensive online dictionaries. Rival writing systems have evolved, and there is ongoing debate within the Taiwanese mother tongue movement as to which system should be used. Versions of pe̍h-ōe-jī have been devised for other Chinese varieties, including Hakka and Teochew Southern Min.
The name pe̍h-ōe-jī (Chinese: 白話字; pinyin: Báihuà zì) means "vernacular writing", written characters representing everyday spoken language. The name vernacular writing could be applied to many kinds of writing, romanized and character-based, but the term pe̍h-ōe-jī is commonly restricted to the Southern Min romanization system developed by Presbyterian missionaries in the 19th century.
The missionaries who invented and refined the system used, instead of the name pe̍h-ōe-jī, various other terms, such as "Romanized Amoy Vernacular" and "Romanized Amoy Colloquial." The origins of the system and its extensive use in the Christian community have led to it being known by some modern writers as "Church Romanization" (教會羅馬字; Jiàohuì Luōmǎzì; Kàu-hōe Lô-má-jī) and is often abbreviated in POJ itself to Kàu-lô. (教羅; Jiàoluō) There is some debate on whether "pe̍h-ōe-jī" or "Church Romanization" is the more appropriate name.
Objections to "pe̍h-ōe-jī" are that it can refer to more than one system and that both literary and colloquial register Southern Min appear in the system and so describing it as "vernacular" writing might be inaccurate. Objections to "Church Romanization" are that some non-Christians and some secular writing use it. One commentator observes that POJ "today is largely disassociated from its former religious purposes." The term "romanization" is also disliked by some, who see it as belittling the status of pe̍h-ōe-jī by identifying it as a supplementary phonetic system instead of a fully-fledged orthography. Sources disagree on which of the two is more commonly used.