A language family
In Chinese and other East Asian societies, a red envelope or red packet / red pocket (known as Hóng Bāo in Mandarin, Ang Pao in Hokkien and Lai See in Cantonese, and "lì xì" in Vietnamese) is a monetary gift which is given during holidays or special occasions.
Red envelopes are mainly presented at social and family gatherings such as weddings or on holidays such as the Lunar New Year. The red color of the envelope symbolizes good luck and is supposed to ward off evil spirits.
The amount of money contained in the envelope usually ends with an even digit, in accordance with Chinese beliefs; for instance 88 and 168 are both lucky numbers, as odd-numbered money gifts are traditionally associated with funerals. But there is a widespread tradition that money should not be given in fours, or the number four should not appear in the amount, as the pronunciation of the word "four" resembles that of the word "death", and it signifies bad luck for many Chinese (See Numbers in Chinese culture). At weddings, the amount offered is usually intended to cover the cost of the attendees as well as a goodwill to the newly weds.
During Lunar New Year, mainly in South China, red envelopes (in the North, just money without any cover) are typically given to the unmarried by the married. The amount of money is usually a single note to avoid heavy coins, and to make it difficult to judge the amount inside before opening.