Related Rule
United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 59. Improper Use of the Distinctive Emblems of the Geneva Conventions
The UK Military Manual (1958) provides:
Use of the emblem of a red cross (red crescent, red lion and sun) on a white ground is authorised in order to indicate military hospitals and other military medical establishments as well as, subject to the authorisation of the Government, civilian hospitals and hospital trains.
The emblem must not be used for other purposes. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 302; see also § 377.
The manual further states:
Improper use of the Red Cross emblem is forbidden. The flag with the distinctive emblem must not be used to cover vehicles used for the transport of ammunition and non-medical stores. A hospital train must not be used to facilitate the escape of combatants. It is forbidden to fire from a tent, building or vehicle flying the flag with the distinctive emblem. A hospital or other building protected by the flying of the flag with the distinctive emblem … must not be used as an observation post or military office or store. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 317.
The manual also states: “In addition to the ‘grave breaches’ of the 1949 [Geneva] Conventions, … the following are examples of punishable violations of the laws of war, or war crimes: … misuse of the Red Cross or equivalent emblems.” 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 626(e).
The UK LOAC Pamphlet (1981) provides: “It is forbidden … to make improper use in combat of … the Red Cross or Red Crescent emblems.” 
United Kingdom, The Law of Armed Conflict, D/DAT/13/35/66, Army Code 71130 (Revised 1981), Ministry of Defence, prepared under the Direction of The Chief of the General Staff, 1981, Section 4, p. 12, § 2d.
The UK LOAC Manual (2004) states:
It is prohibited to … make improper use of the distinctive emblem of the red cross, red crescent or red lion and sun or of other emblems, signs or signals provided for by the [1949] Geneva Conventions or by [the 1977] Additional Protocol I. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 5.10.
With regard to internal armed conflict, the manual provides: “It is prohibited to make improper use of the … the red cross or red crescent emblems”. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 15.13.
In its chapter on enforcement of the law of armed conflict, the manual states:
The Hague Regulations 1907 are now recognized as part of customary law. Those regulations provide that the following acts are “especially forbidden”:
f. to make improper use of … the distinctive emblems of the Geneva Convention. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 16.27.
The UK Geneva Conventions Act (1957), as amended in 1995, provides that, “subject to the provisions of this section, it shall not be lawful for any person, without the authority of the Secretary of State, to use for any purpose whatsoever” the emblems of the red cross, red crescent and red lion and sun on a white ground, the heraldic emblem of Switzerland, the designations “Red Cross”, “Geneva Cross”, “Red Crescent” and “Red Lion and Sun”, as well as any design or wording so nearly resembling any of those emblems or designations as to be capable of being mistaken for, or, as the case may be, understood as referring to, one of those emblems or designations. 
United Kingdom, Geneva Conventions Act, 1957, as amended in 1995, Section 6.
The UK Geneva Conventions Act (1957), as amended in 2009, states:
Use of Red Cross and other emblems.
(1) Subject to the provisions of this section, it shall not be lawful for any person, without the authority of the Secretary of State, to use for any purpose whatsoever any of the following … ; that is to say –
(a) the emblem of a red cross with vertical and horizontal arms of the same length on, and completely surrounded by, a white ground, or the designation “Red Cross” or “Geneva Cross”;
(b) the emblem of a red crescent moon on, and completely surrounded by, a white ground, or the designation “Red Crescent”;
(c) the following emblem in red on, and completely surrounded by, a white ground, that is to say, a lion passing from right to left of, and with its face turned towards, the observer, holding erect in its raised right forepaw a scimitar, with, appearing above the lion’s back, the upper half of the sun shooting forth rays, or the designation “Red Lion and Sun”.
(f) the emblem of a red frame in the shape of a square on edge on a white ground, conforming to the illustration in Article 1 of the Annex to the third protocol (and whether or not incorporating another emblem, or a combination of emblems, in accordance with Article 3 of the protocol), or the designation “Red Crystal” or “third Protocol emblem”. 
United Kingdom, Geneva Conventions Act, 1957, as amended on 2 July 2009, Section 6(1)(a)–(c) and (f).
Under the UK ICC Act (2001), it is a punishable offence to commit a war crime as defined in Article 8(2)(b)(vii) of the 1998 ICC Statute. 
United Kingdom, ICC Act, 2001, Sections 50(1) and 51(1) (England and Wales) and Section 58(1) (Northern Ireland).
A training video on IHL produced by the UK Ministry of Defence illustrates the rule that the false use of emblems is forbidden. 
United Kingdom, Ministry of Defence, Training Video: The Geneva Conventions, 1986, Report on UK Practice, 1997, Chapter 2.4.
On the basis of a letter from the British Red Cross, the Report on UK Practice notes that, since 1988, four cases have been initiated in the United Kingdom “regarding the use of designs resembling the red cross emblem” and stresses that “unauthorised use of such emblems is prohibited at all times within UK territory, regardless of the nature of a particular conflict”. 
Report on UK Practice, 1997, Letter from the British Red Cross, 8 October 1997, Chapter 2.5.