Qi 啟 or qiben 啟本, during the Jin period 晉 (265-420) called qishi 啟事, were memorials addressed to the emperor, the heir apparent or princes. xxx 劉勰《文心雕龍·奏啟》：“必斂飭入規，促其音節，辨要輕清，文而不侈，亦啟之大略也。” 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 communication directly to the emperor, but the Northern Wei 北魏 (386-534) reduced the 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 brief and simple. Documents of the type used the formulas xxx 啟聞”、“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 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.