Taijitu as the Joseon royal standard. Since the 1960s, "yin-yang symbol" is most widely applied to the "He tu" symbol which combines the two interlocking spirals with two dots. In the standard form of the contemporary "yin-yang symbol", one draws on the diameter of a circle two non-overlapping circles each of which has a diameter equal to the radius of the outer circle. One keeps the line that forms an "S", and one erases or obscures the other line. The design is also described "pair of fishes nestling head to tail against each other". The Soyombo symbol of Mongolia may be
Taijitu the "yin and yang symbol", itself popularly called "taijitu", represents the second of these five parts of the diagram. The term "taijitu" in modern Chinese is commonly used to mean the simple "divided circle" form (), but it may refer to any of several schematic diagrams that contain at least one circle with an inner pattern of symmetry representing yin and yang. While the concept of yin and yang dates to Chinese antiquity, the interest in "diagrams" (圖 "tú") is an intellectual fashion of Neo-Confucianism during the Song period (11th century), and it declined again in the Ming period, by