The Yili is one of four extant collections of ritual matters of the Zhou Dynasty 周. The final redactional work on these books took place during the Han Dynasty 漢. Three of them were incorporated into the Canon of Confucian Classics: Liji 禮記, Yili, and Zhouli 周禮. The fourth, the Da Dai Liji 大戴禮記, has only survived in fragments and was almost forgotten for centuries.
Until the end of the Han Dynasty, the Yili was known under the name Ligujing 禮古經 "The Old Classic about Ritual Matters", edited by the Masters Hou 后氏 and Dai 戴氏. The book Yili contains rules of behaviour and etiquette for the low level aristocracy, with chapters that describe the very sophisticated etiquette during capping of a young man, his marriage, behaviour during a symposium or an archery contest, during an imperial audience, a funeral with special mourning clothes and mourning periods. It is indended as an instruction for the private life and for official events like interstate meetings. Some of the 17 chapters (or 40 parts) contain commentaries, partially integrated into the text. Like many Zhou books, the Yili is said to be a compilation of the Duke of Zhou 周公旦. But we can find no trace of it before Han times. During the Han Dynasty, it was the object of many discussions, commentaries and publishings of which the version handed down by Liu Xiang 劉向 is the form still existant today. Two other versions Dai 戴 uncle and nephew were not very different.
The only English translation by John Steele dates 1917.
The chapters of the Yili are:

1.士冠禮 Shi Guanli Capping of an ordinary officer's son 2.士昏（＝婚）禮 Shi Hunli Marriage of an ordinary officer 3. 士相見禮 Shi Xiangjian Li Visit of one ordinary officer to another 4. 鄉飲酒禮 Xiang Yinjiu Li District symposium 5. 鄉射禮 Xiang Sheli District archery contest 6.燕禮 Yanli The banquet 7.大射 Dashe The great archery contest 8. 聘禮 Pinli Interstate Missions 9. 公食大夫禮 Gongshi Dafu Li The dinner to the commissioner 10. 覲禮 Jinli The audience 11.喪服 Sangfu Mourning garments 12. 士喪禮 Shi Sangli Obsequies of an ordinary officer I 13. 既夕禮 Jixi Li Obsequies of an ordinary officer II 14. 士虞禮 Shi Yuli The sacrifices of repose 15. 特牲饋食禮 Tesheng Kuishi Li The single beast offered in food to the ancestor 16. 少牢饋食禮 Shaolao Kuishi Li The smaller set of beasts offered as food to the ancestor 17. 有司徹 Yousi Che The assistant clears away

Examples of two chapters of the Yili, the Nuptial Rites and the Mourning Clothes, showing the complex and sophisticated social obligations of Confucian China.

２．士昏(＝婚)禮
昏禮：下達，納采，用雁。主人筵于戶西，西上，右几。使者玄端至，擯者出 請事，入告。主人如賓服，迎于門外，再拜，賓不答拜。揖入。至于廟門， 揖入；三揖，至于階，三讓。主人以賓升，西面。賓升西階，當阿，東面致命。 主人阼階上北面再拜；授于楹間，南面。賓降，出。主人降，授老雁。擯者出請 ，賓執雁，請問名，主人許。賓入授，如初禮。
Chapter 3: The Marriage of an ordinary officer (1)
In making known his intentions to the father of the girl, the father of the young man sends a wild goose.
The girl's father spreads a mat for the ancestral spirit to the west of the door of the room in the ancestral temple, the upper end of it being to the west; and at the right end of the mat he places a body-rest.
When the messenger with the present arrives, dressed in dark square-clothes, the usher goes out to ask his business, and then enters and announces it. The子曰：「昔者明王事父孝，故事天明；事母孝，故事地察；長幼，故上下治； 天地明察，神明彰矣！故雖天子，必有尊也，言有父也；必有先也，言有兄也。 宗廟致敬，不忘親也；修身慎行，恐辱先也；宗廟致敬，鬼神著矣。孝悌之至， 通於神明，光于四海，無所不通。《詩》云：『自西自東，自南自北， 無思不服。[3.1.10.(244)＜文王有聲＞]』」
The Influence of Filial Piety and the Response to it
'The Master said, 'Anciently, the intelligent kings served their fathers with filial piety, and therefore they served Heaven with intelligence; they served their mothers with filial piety, and therefore they served Earth with discrimination. They pursued the right course with reference to their (own) seniors and juniors, and therefore they secured the regulation of the relations between superiors and inferiors (throughout the kingdom). When Heaven and Earth were served with intelligence and discrimination, the spiritual intelligences displayed (their retributive power). Therefore even the Son of Heaven must have some whom he honours; that is, he has his uncles of his surname. He must have some to whom he concedes the precedence; that is, he has his cousins, who bear the same surname, and are older than himself. In the ancestral temple he manifests the utmost reverence, showing that he does not forget his parents; he cultivates his person and is careful of his conduct, fearing lest he should disgrace his predecessors. When in the ancestral temple he exhibits the utmost reverence, the spirits of the departed manifest themselves. Perfect filial piety and fraternal duty reach to (and move) the spiritual intelligences, and diffuse their light on all within the four seas; they penetrate everywhere. It is said in the Book of Poetry, " the west to the east, the south to the north, There was not a thought but did him homage."'

Translated by James Legge