Related Rule
Colombia
Practice Relating to Rule 46. Orders or Threats That No Quarter Will Be Given
Colombia’s Basic Military Manual (1995) states that it is prohibited to order that there shall be no survivors. 
Colombia, Derecho Internacional Humanitario – Manual Básico para las Personerías y las Fuerzas Armadas de Colombia, Ministerio de Defensa Nacional, 1995, p. 49.
In a case concerning conscientious objection in 1992, Colombia’s Constitutional Court considered that a superior’s order that would cause “death outside combat” would clearly lead to a violation of human rights and of the Constitution and as such could be disobeyed. 
Colombia, Constitutional Court, Constitutional Case No. T-409, Judgment, 8 June 1992.
In 1995, in its examination of the constitutionality of the 1977 Additional Protocol II, Colombia’s Constitutional Court considered that Article 4 of the Protocol, including the prohibition on ordering that there shall be no survivors, perfectly met constitutional standards. The Constitution contained provisions on the protection of human life and dignity. 
Colombia, Constitutional Court, Constitutional Case No. C-225/95, Judgment, 18 May 1995.
In 1995, in its examination of the constitutionality of a military regulation which provided that subordinates were obliged to obey a superior’s order that they considered unlawful if the order was confirmed in writing, Colombia’s Constitutional Court stated that an order that would cause death outside combat would clearly be a violation of human rights and of the Constitution. 
Colombia, Constitutional Court, Constitutional Case No. C-578, Judgment, 4 December 1995.