Bopomofo (), or Mandarin Phonetic Symbols, also named Zhuyin (), is a Chinese transliteration system for Mandarin Chinese and other related languages and dialects. More commonly used in Taiwanese Mandarin, it may also be used to transcribe other varieties of Chinese, particularly other varieties of Mandarin Chinese dialects, as well as Taiwanese Hokkien. Consisting of 37 characters and five tone marks, it transcribes all possible sounds in Mandarin. Bopomofo was first introduced in China by the Republican government in the 1910s and was used alongside the Wade–Giles system for romanization purposes, which used a modified Latin alphabet. Today, Bopomofo is now more common in Taiwan than on the Chinese mainland, and is after Hanyu Pinyin used as a secondary electronic input method for writing Mandarin Chinese in Taiwan as well as in dictionaries or other non-official documents. Etymology Bopomofo is the name used by the ISO and Unicode. Zhuyin () literally means phonetic notation. The original formal name of the system was and . It was later renamed . In official documents, Bopomofo is occasionally called "Mandarin Phonetic Symbols I" (), abbreviated as "MPS I" The system is often also called either Chu-in or the Mandarin Phonetic Symbols. A romanized phonetic system was released in 1984 as Mandarin Phonetic Symbols II (MPS II). The name Bopomofo comes from the first four letters of the system: ㄅ, ㄆ, ㄇ and ㄈ. Similar to the way that the word "alphabet" is ultimately derived from the names of the first two letters of the alphabet (alpha and beta), the name "Bopomofo" is derived from the first four syllables in the conventional ordering of available syllables in Mandarin Chinese. The four Bopomofo characters () that correspond to these syllables are usually placed first in a list of these characters. The same sequence is sometimes used by other speakers of Chinese to refer to other phonetic systems. History Origins The Commission on the Unification of Pronunciation, led by Wu Zhihui from 1912 to 1913, created a system called Zhuyin Zimu, which was based on Zhang Binglin's shorthand. It was used as the official phonetic script to annotate the sounds of the characters in accordance with the pronunciation system called "Old National Pronunciation" (Laoguoyin). A draft was released on July 11, 1913, by the Republic of China National Ministry of Education, but it was not officially proclaimed until November 23, 1928. It was later renamed first