The general trend of the word "Ti" is from Oracle Bone Inscriptions, bronze inscriptions to seal script, and then to official script and regular script. Official script is the simplification of seal script, cursive script and running script are the simplification of official script, and simplified characters are the simplification of regular script. Regular script began to appear in Wei and Jin Dynasties, and simplified characters appeared in inscriptions in the Southern and Northern Dynasties (4th-6th century). In the Sui and Tang Dynasties, simplified characters gradually increased, which were quite common among the people and were called "vulgar characters".