Tongzhi (Comprehensive Treatises)
Zheng Qiao's (郑樵) encylopedia Tongzhi (通志) in 200 chapters is in first place a compendium of administrative regulations of the Song period. But unlike Du You's (杜佑) statecraft encyclopedia Tongdian (通典) and Ma Duanlin's (马端临) book Wenxian tongkao (文献通考) the Tongzhi comprises many treatises (略) that are not directly related to state administration or governmental regulations but are of general interest, like literature, fauna and flora, or the many biographies of eminent people. Because the biographies constitute the largest part of the Tongzhi it is counted as a historiographical book rather than an encyclopedia. Many of the treatises can be compared with the treatises that are incorporated in the official dynastic histories.
Zheng Qiao followed to proposals of the Tang period scholar Liu Zhiji (刘知几) who in his historic critique Shitong (史通) described how to compile objective histories and renounced earnestly discussing the belief in omina. Zheng Qiao added the treatises of noble families, capitals and cities, and of flora and fauna. The treatises on the Confucian classics and on music theory are a new creation by Zheng Qiao himself. The part of literature was divided into general literature, collations, atlases or illustrated books, and bronze and stone inscriptions.
The Qing government had compiled two sequels to Zheng Qiao's book: Xu tongzhi (续通志), and Qingchao tongzhi (清朝通志) (皇朝通志). The latter wholly omits the biographical part.
The term tongzhi became common for the literary type of regional descriptions compiled during the Qing period. In these regional descriptions the treatises of Zheng Qiao's book are incorporated, each giving an account on the various aspects of administration, history, literature etc. in the different provinces of Qing China. Another book using this term is the Baqi tongzhi (八旗通志) "Comprehensive treatises on the Eight Banners."