Qi 啟 or qiben 啟本, called qishi 啟事 during the Jin period 晉 (265-420), were memorials addressed to the emperor, the heir apparent or princes. In his literary critique Wenxin diaolong 文心雕龍 (ch. Zou-qi 奏啟), Liu Xie 劉勰 (c. 470-c. 530) argues that "its nature is pure, it is conformable to the principles of rhetoric and swift in tempo, distinct and clean in presenting arguments, and written in beautiful literary form but without excessive ornamentation" (transl. Shih 1959: 177). Liu Xie also explains that the word qi was not used during the Han period 漢 (206 BCE-220 CE) because it was the tabooed personal name of Emperor Jing 漢景帝 (r. 157-141 BCE). This type of document was thus introduced in the 3rd century CE as a means of direct communication with the emperor, but the Northern Wei 北魏 (386-534) reduced its use to presentations to princes. The process was the same as with documents of the types biao 表 and zou 奏.
The most famous early qi-type documents are Bao Zhao's 鮑照 (c. 414-466) Qing jia qi 請假啟 and Wang Bo's 王勃 (650-676) Shang libu Pei Shilang qi 上吏部裴侍郎啟, or documents written by Ren Fang 任昉 (460-508) and Yu Xin 庾信 (513-581). During the Tang period 唐 (618-907), the designation was used for petitions submitted to functionaries of higher rank, like in Han Yu's 韓愈 (768-824) Shang Zheng Shangshu qi 上鄭尚書啟 and Shang liushou Zheng Xianggong qi 上留守鄭相公啟 or Liu Zongyuan's 柳宗元 (773-819) Shang Guangzhou Li Zongren qi 上廣州李宗儒啟. The language of qi-type documents was straightforward. Documents of the type used the formulas "[I] bring to attention" (qi wen 啟聞) or "[I] respectfully submit [the following matter for consideration]" (jin qi 謹啟). The text was to be written in large characters, but one column should not be longer than 18 characters.
In the form of qiben, this type of document (occasionally called jian 箋) was regularly used during the Ming period 明 (1368-1644) when addressing princes. Qi-type memorials were still used in the early Qing period 清 (1644-1911), for instance, when submitting letters to the prince regent Dorgon (Ch. Duo'ergun 多爾袞, 1612-1650). Qi-type memorials were in the late phase thus practically identical to routine memorials (tiben 題本). The Kangxi Emperor 康熙帝 (r. 1661-1722) confined the use of qi memorials to occasions when governors-general or governors (du-fu 督撫) submitted letters to imperial princes. They were thus similar to documents of the types zi 咨, xiang 詳 or shen 申.