The knot is an East Asian calligraphy term, which refers to the shelf structure of Chinese characters and other square characters. China's famous monographs on structure in ancient times include Thirty-six Laws written by Ou Yangxun in Tang Dynasty, Eighty-four Laws written by Mason Lee in Ming Dynasty and Ninety-two Laws copied from Ying Shao by Huang Ziyuan in Qing Dynasty. Brushwork, structure and composition are the three elements of calligraphy skills.
Japanese, Korean and other East Asian countries influenced by China culture also have structural problems when writing their own characters. Japanese Katakana, Hiragana and Korean proverbs all need careful structure to write more beautifully.