 It is written in a longhand form called "wenzi pu" 〔文字譜〕 (literally "written notation"), said to have been created by Yongmen Zhou (雍門周) during the Warring States period, which gives all the details using ordinary written Chinese characters.Later in the Tang dynasty Cao Rou (曹柔) and others simplified the notation, using only the important elements of the characters (like string number, plucking technique, "hui" number and which finger to stop the string) and combined them into one character notation.This meant that instead of having two lines of written text to describe a few notes, a single character could represent one note, or sometimes as many as nine.