Related Rule
United States of America
Practice Relating to Rule 127. Respect for Convictions and Religious Practices of Persons Deprived of Their Liberty
The US Field Manual (1956) reproduces Articles 34 and 35 of the 1949 Geneva Convention III and Articles 76, 86 and 93 of the 1949 Geneva Convention IV. 
United States, Field Manual 27-10, The Law of Land Warfare, US Department of the Army, 18 July 1956, as modified by Change No. 1, 15 July 1976, §§ 110, 111, 293, 300 and 446.
The US Air Force Pamphlet (1976), referring to Articles 34–38 of the 1949 Geneva Convention III, guarantees prisoners of war enjoyment of religious activities. 
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, § 13-4.
The US Instructor’s Guide (1985) provides: “Even though you are a prisoner, you are entitled to practice your religious faith. All prisoners shall enjoy complete freedom in the exercise and observance of their religious faith.” 
United States, Instructor’s Guide – The Law of War, Headquarters Department of the Army, Washington, April 1985, p. 11.
The US Naval Handbook (1995) provides:
The following acts are representative war crimes: offences against prisoners of war, including … infringement of religious rights; … offences against civilian inhabitants of occupied territory, including … infringement of religious rights. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-2.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Transportation, US Coast Guard, October 1995 (formerly NWP 9 (Rev. A)/FMFM 1-10, October 1989), § 6.2.5.
The US Naval Handbook (2007) states: “All detainees shall … [b]e allowed the free exercise of religion, consistent with the requirements for safety and security.” 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-12.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Homeland Security, US Coast Guard, July 2007, § 11.2.
The US Manual on Detainee Operations (2008) states:
Respect for the religious preferences of detainees is an essential aspect of detainee operations. Accordingly, the organization and administration of the detention facility must not be such as to hinder unjustifiably the observance of religious rites, and commanders should plan for the accommodation of the religious needs of detainees. Certain limitations may be necessary due to security concerns; however, a good faith balance should be struck between the detainee’s obligation to comply with disciplinary rules and procedures and the detaining power’s obligation to afford detainees the ability to meet their religious obligations and exercise their religious practices. The detaining power is also prohibited from imposing any adverse distinctions within the detainee population based on religion. In this regard, it should be noted that in some situations, segregating the detainee population based on religious affiliation may be beneficial and therefore not prohibited, particularly when conflict has been based in part on religious affiliation. Detainees have no right to person-to-person support by military chaplains. Therefore JFCs [joint force commanders] are under no obligation to provide such support. Accordingly, military chaplains do not generally provide direct religious support to detainees. Should the JFC determine a requirement to provide direct military chaplain support to detainees, communications between the chaplains and the detainees will be privileged to the extent provided by Military Rule of Evidence 503 and appropriate Military Department policies. 
United States, Manual on Detainee Operations, Joint Chiefs of Staff, 30 May 2008, pp. III-8–III-9.
The manual also states: “Ideally, the TIF [theater internment facility] will have: … religious and morale facilities.” 
United States, Manual on Detainee Operations, Joint Chiefs of Staff, 30 May 2008, p. IV-4.
The manual also states:
Detainee Categories
The DOD [Department of Defense] definition of the word “detainee” includes any person captured, detained, or otherwise under the control of DOD personnel (military, civilian, or contractor employee) … It does not include persons being held primarily for law enforcement purposes except where the United States is the occupying power …
a. Enemy Combatant. In general, a person engaged in hostilities against the United States or its coalition partners during an armed conflict. The term “enemy combatant” includes both “lawful enemy combatants” and “unlawful enemy combatants.”
b. Enemy Prisoner of War. Individual under the custody and/or control of the DOD according to Articles 4 and 5 of the … [1949 Geneva Convention III].
c. Retained Personnel … Personnel who fall into the following categories: official medical personnel of the armed forces exclusively engaged in the search for, or the collection, transport, or treatment of wounded or sick, or in the prevention of disease, and staff exclusively engaged in the administration of medical units and facilities; chaplains attached to enemy armed forces; staff of national Red Cross Societies and that of other volunteer aid societies duly recognized and authorized by their governments to assist medical service personnel of their own armed forces, provided they are exclusively engaged in the search for, or the collection, transport or treatment of, the wounded or sick, or in the prevention of disease, and provided that the staff of such societies are subject to military laws and regulations.
d. Civilian Internee … A civilian who is interned during an armed conflict, occupation, or other military operation for security reasons, for protection, or because he or she has committed an offense against the detaining power. 
United States, Manual on Detainee Operations, Joint Chiefs of Staff, 30 May 2008, pp. I-3–I-5; see also pp. viii and GL-3.
According to the Report on US Practice, “Articles 4, 5 and 6 [of the 1977 Additional Protocol II] reflect general US policy on treatment of persons in the power of an adverse party in armed conflicts governed by common Article 3” of the 1949 Geneva Conventions. The report also notes: “It is the opinio juris of the US that persons detained in connection with an internal armed conflict are entitled to humane treatment as specified in Articles 4, 5 and 6 [of the 1977 Additional Protocol II].” 
Report on US Practice, 1997, Chapter 5.3.
In August 2003, the US State Department issued a written response to an opinion issued by the United Nations Commission on Human Rights (UNCHR), dated 8 May 2003, that had referred to a UNCHR Working Group report on Arbitrary Detention, dated 8 January 2003, which was critical of US policy regarding detainees held at the US naval base at Guantanamo Bay, Cuba. In disagreeing with the UNCHR reports, and noting that the competence of the Working Group did not extend to the laws and customs of war, the US response stated that “[t]he detainees have been given … the opportunity to worship freely and many have been given copies of the Koran in their native language”. 
United States, State Department, Response to UNCHR Opinion No. 5/2003 of 8 May 2003 and the Communication of 8 January 2003 of the Working Group on Arbitrary Detention, August 2003.
In March 2006, the US Government issued a written response to a report produced by a group of five special rapporteurs to the United Nations Commission on Human Rights, dated 16 February 2006, which was critical of US policy regarding detainees at Guantanamo Bay, Cuba. The US Government’s response stated in part:
• [Detainees are provided with] opportunity to worship, including prayer beads, oils, rugs, calls to prayer five times daily, and copies of the Koran in the detainee’s native language.
• Following allegations of Koran mishandling by the United States at Guantanamo, the Department of Defense conducted an investigation into the matter. The investigation, completed on June 3, 2005, found that in 31,000 documents covering 28,000 interrogations and countless thousands of interactions with detainees, five incidents of apparent mishandling of the Koran by guards or interrogators had occurred.
• Some 1,600 Korans have been distributed as part of a concerted effort by the United States government to facilitate the desires of detainees to freely worship. The small number of very regrettable incidents should be seen in light of the volume of efforts to facilitate opportunities for religious practice at Guantanamo. 
United States, Reply of the Government of the United States of America to the Report of the Five UNCHR Special Rapporteurs on Detainees in Guantanamo Bay, Cuba, 10 March 2006, p. 6.