Règle correspondante
Practice Related to Rule 94. Slavery and Slave Trade
Colombia’s Operational Law Manual (2009) states:
For its part, the [1977] Additional Protocol II to the [1949] Geneva Conventions adds to these prohibitions … slavery and the slave trade … and threats to commit any of the foregoing acts. All these prohibitions, even if more specific [in Additional Protocol II], can also be derived from common article 3 [to the Geneva Conventions]. 
Colombia, Manual de Derecho Operacional Manual FF.MM. 3-41 Público, Primera Edición 2009, Comando General de las Fuerzas Militares, aprobado por el Comandante General de las Fuerzas Armadas por Disposición Número 056, 7 December 2009, p. 42.
[footnote in original omitted]
Colombia’s Constitutional Court held in 1995 that the prohibitions contained in Article 4(2) of the 1977 Additional Protocol II were perfectly consistent with the Constitution, since they were not only in harmony with the principles and values of the Constitution, but also practically reproduced specific constitutional provisions. The Court said that the prohibition of Article 4(2)(f) was almost identical to Article 17 of the Constitution. 
Colombia, Constitutional Court, Constitutional Case No. C-225/95, Judgment, 18 May 1995.
In 2007, in the Constitutional Case No. C-291/07, the Plenary Chamber of Colombia’s Constitutional Court stated:
[T]he essential principles of international humanitarian law have acquired ius cogens status, based on the fact that the international community as a whole has recognised their peremptory and imperative nature in the same way it has recognised this for other cardinal provisions such as … the prohibition of slavery. 
Colombia, Constitutional Court, Constitutional Case No. C-291/07, Judgment of 25 April 2007, p. 70.