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 host, dressed like the messenger, goes to meet him outside the door, and bows twice, the messenger not bowing in reply. Then the host invites him with a salute to enter.
When they come to the temple gate, the host invites the guest with a salute to enter. In their progress up the court there are the three customary salutes; and when they come to the steps they yield precedence three times.
The host precedes the guest, going up the eastern steps, and faces westward, while the guest goes up the west steps, and, standing under the main beam of the hall, delivers his message, the host boing twice at the top of the eastern steps, with his face north. The host, standing between the pillars, and facing south, receives the goose. Thereafter the visitor descends the steps and leaves. The host also descends, and hands the goose to his head servant.
When the messenger the father arrives, the usher goes out and holding a goose in his hands, requests permission to be allowed to ask the girl's name, and the host, through the usher, consents. The visitor then enters and hands over the present to the host, observing the ceremonial already described.

１１．喪服
喪服：斬衰裳，苴絰、杖、絞帶，冠繩纓，菅屨者，＜傳＞曰：斬者何﹖不緝也 。苴絰者，麻之有蕡者也...
父，＜傳＞曰：陘鬫韞H斬衰也﹖父，至尊也。
諸侯為天子，＜傳＞曰：天子，至尊也。
君，＜傳＞曰：君，至尊也。
父為長子，＜傳＞曰：何以三年也﹖正體於上，又乃將所咫]。庶子不得為長子三年，不繼祖也。
為人後者。＜傳＞曰：何以三年也﹖受重者，必以尊服服之。何如而可為之後﹖ 同宗則可為之後。何如而可以為人後﹖支子可也。為所後者之祖父母、妻，妻之 父母、昆弟，昆弟之子，若子。
妻為夫，＜傳＞曰：夫，至尊也。
妾為君，＜傳＞曰：君，至尊也...
父在為母，＜傳＞曰：何以期也﹖屈也。至尊在，不敢伸其私尊也。父必三年然 後娶，達子之志也。
妻，＜傳＞曰：為妻何以期也﹖妻，至親也...
父卒，繼母嫁，從；為之服，報。＜傳＞曰：何以期也﹖貴終也。
Chapter 22: Mourning garments (1)
[The three year's untrimmed mourning]
This mourning dress consists of an untrimmed sackcloth coat and skirt, fillets of the female nettle hemp, a staff, a twisted girdle, a hat whose hat-string is of cord, and rush shoes.
<The Commentary> says: Why untrimmed? Because it is not hemmed. The hempen fillet is made the plant when it has sprouted a second time, [and thus is ill-favoured.]...
[This mourning is worn for] a father, <The Commentary> says: Why? Because the father is the most honourable person [in the familiy].
The feudal lords wear it for the Son of Heaven, <The Commentary> says: He is the most honourable person [in the empire].
[The ministers] wear it for their ruler, <The Commentary> says: The ruler is the most honourable person [in his domain].
A father wears it for his oldest son, <The Commentary> says: Why does he have to mourn for three years? Because he is the proper representative of those who have preceded him in the line. It also lays emphasis on what is involved in the [father's] transmission [of the patriarchal right to his posterity]. A son other than the oldest one does not have this three year's [mourning worn] for him, as he does not succeed his ancestors.
For the person whom he has adopted to succeed him, <The Commentary> says: Why does he have to mourn for three years? This is because he has received a place in the succession, and so is entitled to have the deepest grade of mourning worn for him. What is the qualification that one must possess to be thus adopted? He must be in the same family line as the man himself. Who may be called on to take up the succession to another? Anyone but the direct heir. The adopted heir wears mourning for the grandparents of the man whom he succeeds, and for his wife, his wife's father, mother, and brothers, and the children of these last. In all these cases he acts as if he were the regular son.
A wife wears this mourning for her husband, <The Commentary> says: The husband is the most honourable person [in the marital relationship].
A concubine wears it for her lord and master, <The Commentary> says: The lord is the most honourable person [in this relationship]...
[The trimmed mourning with the staff] While the father is still alive this mourning is assumed on the death of the mother, <The Commentary> says: Why to wear this mourning the time [of three years]? As a sign of inferiority. While the most honourable person [in the marriage relationship] is still alive, the son does not dare to exhibit to the full the respect he feels privately for his mother. The father shall abstain taking another wife for three years, however, as an indication that he appreciates the feelings of his son in this matter.
A husband wears it for his wife [three years long], <The Commentary> says: Because the wife's relationship to him is the closest possible...
If the father have died, and his stepmother have married again, [the children who] follow her to her new home wear this mourning for her when she dies, as an act of grace, <The Commentary> says: Why? In acknowledgement of her love for them to the end.

Translated by John Steele 1917