Biao 表 was a type of memorial to the throne (zouyi 奏議) in early and mid-imperial China. The literary theory Wenxin diaolong 文心雕龍 (ch. Zhangbiao 章表) explains, by using a word pun, that biao meant biao 標 "to signify" by expounding one's thoughts about a particular problem (chen qing 陳情). The book Wenzhang yuanqi 文章緣起 by Ren Fang 任昉 (460-508) said that biao meant "to clarify" (ming 明). Related to this meaning, the word biao was also used for tables that are also used to present an overview of the interrelation of complex issues.
The first use of biao-type memorials is dated to the Qin period 秦 (221-206 BCE), and it was widely used during the Han period 漢 (206 BCE-220 CE) for discussions, critique, accusations, protests against unjust verdicts, petitions, requests, recommendations, presentations, congratulations, to signify retirement or to decline offers. One of the most important early memorials is Kong Rong's 孔融 (153-208) recommendation Jian Mi Heng biao 薦禰衡表. Other examples are Zhuge Liang's 諸葛亮 (181-234) Chushi biao 出師表, Cao Zhi's 曹植 (192-232) Qiu tong qinqin biao 求通親親表, Li Mi's 李密 (582-619) Chenqing biao 陳情表, Li Bai's 李白 (701-762) Wei Song Zhongcheng zi jian biao 為宋中丞自薦表, Han Yu's 韓愈 (768-824) Lun Fogu biao 論佛骨表, He huangdi ji wei biao 賀皇帝即位表, Chaozhou cishi xie shang biao 潮州刺史謝上表 or Lun bu zai xing shang biao 論捕賊行賞表, Ouyang Xiu's 歐陽修 (1007-1072) Xie zhi shi biao 謝致仕表 and Zhao Bingwen's 趙秉文 (1159-1232) Zuo canzheng qi zhi shi biao 左參政乞致仕表.
Originally written in prose style, the texts of biao-type memorials were from the 4th century on written in couple style (pianwen 駢文). Literary beauty and quality thus went hand in hand with rhetorical arguments to convince the sovereign to positively respond to the requests or recommendations brought forward in biao-type documents.
From the Tang period 唐 (618-907) on, this wide frame of purposes was narrowed to the use of expressing thanks (chenxie 陳謝), congratulations (qinghe 慶賀), and presentations (jinxian 進獻). Two other purposes for which biao-type documents were used in late imperial China were declarations of submission after military defeat (jiangbiao 降表), and the last will of high officials on the deathbed (yibiao 遺表). During the Song period 宋 (960-1279), personal memos (huji 笏記) for reading aloud personal suggestions at the court were also called biao, as a kind of oral memorial, but in contrast to written memorials with their intricate language, these texts were rather simple.
During the Yuan period 元 (1279-1368), officials of rank 5 and higher submitted congratulations (biaozhang 表章, hebiao 賀表) to the emperor on the occasion of his birthday (shoudan 壽旦), on New Year's Day (yuandan 元旦) or the day of the winter solstice (dongzhi 冬至, see calendar; together called the three great festivities, sandajie 三大節). In addition to this, the Ming dynasty 明 (1368-1644) introduced a similar type called jianwen 箋文 to be used to congratulate the empress.
During the Qing period 清 (1644-1911), enthronement, investiture of empresses or the conferment of honorific titles to members of the imperial family also belonged to matters of congratulation. Another occasion the word biao was used for was the finalization of a large state-sponsored book project like the veritable records (shilu 實錄) of a reign, "sacred instructions" (shengxun 聖訓), administrative history (huidian 會典) or historiographical works. In this case, the chief compiler (zongcaiguan 總裁官) submitted a biao-type memorial reporting on the finished project. The word was also used for documents used by representatives of foreign tribute states for the submitting of tributes.