pinyin is the mandarin word for "spelling", writing letters showing the sound of a word in place of a chinese character. today, it almost always has the sense of hanyu pinyin, the way of writing mandarin sounds which has been used by the people's republic of china from the 1950s. other countries like the united states and taiwan used other ways of spelling chinese (such as the wade-giles way) for a long time, but in the late 20th century started to use hanyu pinyin as well. it is the standard of china as well as the united nations. it is the most common romanization system for chinese.