Règle correspondante
Canada
Practice Relating to Rule 46. Orders or Threats That No Quarter Will Be Given
Canada’s LOAC Manual (1999) states:
It is prohibited to deny quarter. In other words, it is unlawful to order, imply or encourage that no prisoners will be taken; to threaten an adversary party that such an order will be given; or to conduct hostilities on the basis that no prisoners will be taken. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 6-2, § 15 (land warfare); see also p. 7-3, § 20 (air warfare).
The manual also considers that “declaring that no quarter will be given” is a war crime. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 16-3, § 20(d).
The manual further states: “Article 4(1) of [the 1977 Additional Protocol II] extends to non-international armed conflicts the principle of customary international law that it is prohibited to order that there shall be no survivors.” 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 17-3, § 20.
Canada’s Code of Conduct (2001) provides: “It is unlawful … to order that no PWs or detainees will be taken. It is also illegal as well as operationally unsound to make threats to opposing forces that no PWs [prisoners of war] or detainees will be taken.” 
Canada, Code of Conduct for CF Personnel, Office of the Judge Advocate General, 4 June 2001, Rule 5, § 2.
Canada’s LOAC Manual (2001) states in its chapter on targeting: “It is prohibited to order that there shall be no survivors or to conduct hostilities on that basis. Hence, a person who clearly shows an intent to surrender by whatever means shall not be attacked.” 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 433.3.
In its chapter on land warfare, the manual further states:
It is prohibited to deny quarter. In other words, it is unlawful to order, imply or encourage that no prisoners will be taken; to threaten an adverse party that such an order will be given; or to conduct hostilities on the basis that no prisoners will be taken. 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 608.1.
Similarly, in its chapter on air warfare, the manual states:
It is prohibited to deny quarter. In other words it is unlawful to order, imply or encourage that no prisoners are to be taken; to threaten an adverse party that such an order will be given; or to conduct hostilities on the basis that no prisoners will be taken. 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 707.1.
In its chapter on “War crimes, individual criminal liability and command responsibility”, the manual states that “declaring that no quarter will be given” constitutes a war crime. 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 1609.2.d.
In its chapter on non-international armed conflicts, the manual states: “Article 4(1) of [the 1977 Additional Protocol] II extends to non-international armed conflicts the principle of customary international law that it is prohibited to order that there shall be no survivors.” 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 1712.
Rule 5 of Canada’s Code of Conduct (2005) instructs: “Do not attack those who surrender.” 
Canada, Code of Conduct for CF Personnel, Office of the Judge Advocate General, 2005, Rule 5.
The Code of Conduct also states:
The “denial of quarter” is prohibited. In other words, it is unlawful to refuse to accept someone’s surrender or to order that no PWs [prisoners of war] or detainees will be taken. It is also illegal as well as operationally unsound to make threats to opposing forces that no PWs or detainees will be taken. 
Canada, Code of Conduct for CF Personnel, Office of the Judge Advocate General, 2005, Rule 5, § 2.
Canada’s Crimes against Humanity and War Crimes Act (2000) provides that the war crimes defined in Article 8(2) of the 1998 ICC Statute are “crimes according to customary international law” and, as such, indictable offences under the Act. 
Canada, Crimes against Humanity and War Crimes Act, 2000, Section 4(1) and (4).
In the Abbaye Ardenne case in 1945, the Canadian Military Court at Aurich convicted a German commander of having incited and counselled his troops to deny quarter to Allied troops. 
Canada, Military Court at Aurich, Abbaye Ardenne case, Judgment, 28 December 1945.
In 2013, in the Sapkota case, Canada’s Federal Court dismissed a request for review of a decision denying refugee protection to the applicant on grounds of complicity in crimes against humanity in Nepal between 1991 and 2009. While reviewing the submissions of the respondent, Canada’s Minister of Citizenship and Immigration, the Court stated: “The Respondent notes that the Rome Statute of the International Criminal Court … is endorsed in Canada as a source of customary law.” 
Canada, Federal Court, Sapkota case, Reasons for Judgment and Judgment, 15 July 2013, § 28.