Mandarin phonetic symbols (MPS), phonetic alphabet for Chinese used esp. in Taiwan, also known colloquially as Bopomofo (after the first four letters of the alphabet:ㄅㄆㄇㄈ)
Definitions (Wiktionary)
noun
Zhuyin fuhao, Zhuyin, a phonetic alphabet used to transcribe Mandarin for students of that language and for inputting Chinese, used in Taiwan, also known as bopomofo (syn.) 国音, 注音字母, 國音