quality:correction, stylistic:tone, structural:summarization, structural:expansion
Traditional Shuowen Jiezi classification

The Shuowen Jiezi is a character dictionary authored c. 100 CE by the scholar Xu Shen (c. 58 – c. 148 CE). In its postface, Xu analyses what he sees as all the methods by which characters are created. Later authors iterated upon Xu's analysis, developing a categorisation scheme known as the ' six writings ' (六书; 六書; liùshū), which identifies every character with one of six categories that had previously been mentioned in the Shuowen Jiezi. For nearly two millennia, this scheme was the primary framework for character analysis used throughout the Sinosphere. Xu based most of his analysis on examples of Qin seal script that were written down several centuries before his time—these were usually the oldest specimens available to him, though he stated he was aware of the existence of even older forms. The first five categories are pictographs, indicatives, compound ideographs, phono-semantic compounds, and loangraphs. The sixth category is given by Xu as 轉注 (zhuǎnzhù; ' reversed and refocused '); however, its definition is unclear, and it is generally disregarded by modern scholars.

Modern scholars agree that the theory presented in the Shuowen Jiezi is problematic, failing to fully capture the nature of Chinese writing, both in the present, as well as at the time Xu was writing. Traditional Chinese lexicography as embodied in the Shuowen Jiezi has suggested implausible etymologies for some characters. Moreover, several categories are considered to be ill-defined: for example, it is unclear whether characters like 大 (' large ') should be classified as pictographs or indicatives. However, awareness of the 'six writings' model has remained a common component of character literacy, and often serves as a tool for students memorising characters.