Decrees (zhishu 制書) were in early imperial China the most important type of edicts and orders (zhaoling 詔令). The type was perhaps identical with the early Zhou-period form of "speeches (to the army)" (shi 誓), a word that is pronounced similar to zhi. The word and the character zhi became standard with the foundation of the Qin empire 秦 (221-206 BCE). The Han dynasty 漢 (206 BCE-220 CE) discerned between decrees (zhi 制) and ordinances (zhao 詔) as the highest levels of imperial ordinances. Zhi could only be issued by sovereigns, and were used for important political decisions. The administrative regulations of the Han dynasty, Han zhidu 漢制度 (fragmentarily preserved in Hanguan liu zhong 漢官六種), stipulated that zhi-type decrees were "imperial orders on rules and standards" (di zhe zhidu zhi ming 帝者制度之命).
The Northern Zhou dynasty 北周 (557-581) used the expression tianzhi 天制 "Heavenly decrees".
This narrow frame was widened during the Tang 唐 (618-907) and Song 宋 (960-1279) periods. In a wider sense, the word zhi was used as a general term for ordinances to high-level functionaries, and this form or decree had legal status. In a narrower sense, zhi-type decrees were exclusively used for the appointment and dismissal of high officials or for very important changes. For routine orders, documents of the type zhao were used. During the reign of Empress Wu Zetian 武則天 (r. 690-704), the word zhao was tabooed because her personal name was Zhao 曌. The word zhi was thus used for all imperial decrees and orders.
The use of zhi-type decrees was intensified during the Song period. They were drafted by academicians of Hanlin academicians (Hanlin xueshi 翰林學士) of the Chancellery (menxiasheng 門下省), and were thus called "palace decrees" (neizhi 內制). They were headed by the words menxia 門下, and the text began (zhitou 制頭, poti 破題) in couplet-style (pianwen 駢文) prose with a fix phrase length of 4 or 6 syllables. The document usually ended with the words "[the new functionary] shall this actively carry out" (zhuzhe shixing 主者施行). The use of zhi-type decrees for appointments and dismissals persisted during the Yuan period 元 (1279-1368), but the Ming dynasty 明 (1368-1644) drastically reduced its usage to the announcement of grand state ceremonies or the investiture of an heir apparent or an empress. The decree was formally presented to persons invited to the happenings.
The expression zhi was also used for documents not belonging to the group of imperial edicts and orders, namely lists of candidates who had passed the metropolitan examination – the "yellow" or "golden lists" (huangbang 黃榜, jinbang 金榜), announcements (gaoming 誥命), and instructions (chiming 敕命). These documents began with the formula (zhici 制詞) "having received Heaven's mandate, the emperor decrees that" (feng tian cheng yun, huangdi zhi yue 奉天承運，皇帝制曰).