Nanjing dialect
The spelling "Amoy" is based on pronunciation in Hokkien, the local language. "Peking" is carried over from the d'Anville map. In Nanking syllabary, the city is "Pehking". The irregular "oo" in "Soochow" is to distinguish this city from Xuzhou (Suchow) in northern Jiangsu. The other postal romanizations are based on "Southern Mandarin," an idealized form of Nanjing dialect. Pinyin spellings are based on "putonghua", an idealization of Beijing dialect taught in the Chinese education system.