These prohibitions are strictly followed by initiated Khalsa Sikhs who have undergone initiation. While the Sikh gurus did not enforce religion and did not believe in forcing people to follow any particular religion in general, the Sikh community does encourage all people to become better individuals by following the Guru's Advice (Gurmatta), as opposed to living life without the Guru's code of disciple (Man-mat):
Eating the meat of an animal slaughtered the Muslim or Jewish way (Kutha meat).[3] This is the absolute minimum required by all initiated Sikhs. Although lacto vegetarianism is practiced and recommended by some Sikhs, many Sikhs refrain from eating non-vegetarian food, and believe all should follow this diet. This is due to various social, cultural, political, and familial aspects. As such, there has always been major disagreement among Sikhs over the issue of eating non-vegetarian food. Sikhs following the Rehat (Code of Conduct) of the Damdami Taksal & Akhand Kirtani Jatha also subscribe to this view. The Akali Nihangs have traditionally eaten meat and are famous for performing Jhatka.[4][5][6][7] Thus, there is a wide range of views that exist on the issue of a proper "Sikh diet" in the Panth. Nonetheless, all Sikhs agree with the minimum consensus that meat slaughtered via the Muslim (Halal), Jewish (Shechita) methods or any other religiously slaughtered way, is strictly against Sikh principles.[8][9] The Akal Takht represents the final authority on controversial issues concerning the Sikh Panth (community or collective). The Hukamnama (edict or clarification), issued by Akal Takht JathedarSadhu Singh Bhaura dated February 15, 1980, states that eating meat does not go against the code of conduct of the Sikhs. Amritdhari Sikhs can eat meat as long as it is Jhatka meat.[10]
Adultery: Cohabiting with a person other than one's spouse (sexual relations with anyone who you are not married to- originally a prohibition on sexual intercourse with Muslim women, an injunction was made by Guru Gobind Singh not to seize them during warfare as sexual contact with them was seen as polluting. Kahn Singh Nabha of the Singh Sabha Movement had later inferred that the Guru's command was construed as a prohibition on intercourse with a woman other than one's wife.)[11][12][13][14][15][16]
Intoxicants – A Sikh must not take hemp (cannabis), opium, liquor, tobacco, cocaine, narcotics, etc. In short, any intoxicant is not allowed.[17][18][19]Cannabis is generally prohibited, but ritually consumed in edible form by some Sikhs.[20][21] Some Sikh groups, like the Damdami Taksal, are even opposed to drinking caffeine in Indian tea. Indian tea is almost always served in Sikh gurudwaras around the world. Some Akali Nihang groups consume cannabis-containing shaheedi degh (ਭੰਗ), purportedly to help in meditation.[22][23][24]Sūkha parshaad (ਸੁੱਖਾ ਪ੍ਰਰਸਾਦ), "Dry-sweet", is the term Akali Nihangs use to refer to it. It was traditionally crushed and consumed as a liquid, especially during festivals like Hola Mohalla. It is never smoked, as this practice is forbidden in Sikhism.[25] In 2001, Jathedar Santa Singh, the leader of Budha Dal, along with 20 chiefs of Nihang sects, refused to accept the ban on consumption of shaheedi degh by the apex Sikh clergy of Akal Takht - in order to preserve their traditional practices.[26] According to a recent BBC article, "Traditionally they also drank shaheedi degh, an infusion of cannabis, to become closer with God".[27] Baba Santa Singh was excommunicated and replaced with Baba Balbir Singh, who agreed to shun the consumption of bhang.[28]
Other mentioned practices to be avoided, as per the Sikh Rehat Maryada:
Piercing of the nose or ears for wearing ornaments is forbidden for Sikh men and women.[29]
Female infanticide: A Sikh should not kill his daughter; nor should he maintain any relationship with a killer of daughter.[30]
A Sikh shall not steal, form dubious associations or engage in gambling.[31]
It is not proper for a Sikh woman to wear a veil that covers the face or have the face hidden.[32]
Sikhs cannot wear any token of other faiths. Sikhs must not have their head bare or wear caps. They also cannot wear any ornaments piercing through any part of the body.[33]
Hereditary priestly class – Sikhism does not have priests, as they were abolished by Guru Gobind Singh (the 10th Guru of Sikhism).[34] The only position he left was a Granthi to look after the Guru Granth Sahib; any Sikh is free to become Granthi or read from the Guru Granth Sahib.[34]
Worthless talk: Bragging, gossip, lying, slander, "backstabbing," et cetera, are not permitted. The Guru Granth Sahib tells the Sikh, "your mouth has not stopped slandering and gossiping about others. Your service is useless and fruitless."[35]
^"The most special occasion of the Chhauni is the festival of Diwali which is celebrated for ten days. This is the only Sikh shrine at Amritsar where Maha Prasad (meat) is served on special occasions in Langar", The Sikh review, Volume 35, Issue 409 – Volume 36, Issue 420, Sikh Cultural Centre., 1988
^"The tradition traces back to the time of Sri Guru Hargobind Sahib Ji who started the tradition of hunting for Sikhs ... The tradition of ritually sacrificing goats and consuming Mahaparshad remains alive not only with the Nihang Singh Dals, but also at Sachkhand Sri Hazoor Sahib and Sachkhand Sri Patna Sahib (two of the Sikhs holiest shrines)."Panth Akali Budha DalArchived 2010-05-23 at the Wayback Machine
^"Another noteworthy practice performed here is that a goat is sacrificed on Dussehra night every year. This ceremony was performed on Diwali day this year (Oct 28, 2008). The fresh blood of the sacrificed goat is used for tilak on the Guru’s weapons.", SIGNIFICANT DEVELOPMENTS OF THE SIKH COMMUNITY, Dr Madanjit Kaur, Institute of Sikh Studies Institute of Sikh Studies, Madan KaurArchived 2010-06-12 at the Wayback Machine
^"Sikhism, A Complete Introduction" by Dr. H.S. Singha & Satwant Kaur Hemkunt, Hemkunt Press, New Delhi, 1994, ISBN81-7010-245-6
^"Sikh Identity: An Exploration of Groups Among Sikhs" by Opinderjit Kaur Takhar, pg. 51, Ashgate Publishing, Ltd, 2005, ISBN0-7546-5202-5
^Singh, Dharam (2001). Perspectives on Sikhism: Papers Presented at the International Seminar on Sikhism: a Religion for the Third Millennium Held at Punjabi University, Patiala on 27-29 March 2000. Publication Bureau, Punjabi University. p. 89. ISBN9788173807367.
^McLeod, W. H. (2009-07-24). The A to Z of Sikhism. Scarecrow Press. p. 119. ISBN978-0-8108-6344-6. The sexual intercourse item, however is evidently a modern development from the 18th century prohibition of intercourse with Muslim women.
^Fenech, Louis E.; McLeod, W. H. (2014-06-11). Historical Dictionary of Sikhism. Rowman & Littlefield. p. 214. ISBN978-1-4422-3601-1. Sources from the 18th century indicate that sexual contact with Muslim women was polluting, and Guru Gobind Singh is said to have commanded that during warfare they should not be seized for this purpose.