Romanization of Wu Chinese
has four major schools of romanization.
The most popular school, Common Wu Pinyin, was developed by amateur language clubs and local learners. There are two competing schemes; both adhere to the International Phonetic Alphabet and are very similar to each other. The initial scheme was "Wu Chinese Society pinyin", and it formed the basis of "Wugniu pinyin". Wu Chinese Society pinyin in general does not mark tones. The name Wugniu comes from the Shanghainese pronunciation of 吴语. Either of them is the default romanization scheme in most learning materials.
The second and historical school is the missionary school. This school of English-based Latin orthographies was developed by Western missionaries in the late 19th and early 20th centuries and used to write Bible translations and other educational texts. A representative romanization from this school is the Edkins romanization of Shanghainese.
Another school is the Latin Phonetic Method. Its use is in decline. It utilizes the similarities between French and Wu phonetics and thus adheres to both IPA and French orthography. It was developed in 2001 by a Shanghai-born surgeon living in Lyon, France.
The final, and least used school, is developed by modifying Hanyu pinyin as sanctioned by the State Council. It is the only school developed by professional linguists, mostly working in state-administered universities. While more than 20 competing schemes within this school have been published since the 1980s, the most notable one is the Shanghainese Pinyin, developed by Qian Nairong in 2006. This school is often used in formally published dictionaries and textbooks compiled by Qian and others.