Norma relacionada
Practice Relating to Rule 20. Advance Warning
Colombia’s Operational Law Manual (2009) states:
3. Fundamental guarantees and IHL principles
These guarantees have been embodied in principles that guide behaviour during situations of hostilities and must be observed throughout all military operations:
- Principle of precautions in attack: … [T]he Constitutional Court has held that “among the main expressions of the principle of precaution are: … (iii) the obligation of the parties to the conflict to give warning in so far as circumstances permit, in good time and by effective means, of any attack that might affect the civilian population; … .”
4. Rules for the conduct of hostilities
b. Precautions in attack and against the effects of attacks
The principle of precaution requires that military operations be carried out with constant care to spare the civilian population and civilian objects. The following rules, which must be taken into account when planning a military operation, derive from this principle:
- Give adequate advance warning, by effective means, of any attack that may affect the civilian population, unless circumstances do not permit[.] 
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, pp. 36–40 and 52–53.
[footnotes in original omitted]
In 2007, in the Constitutional Case No. C-291/07, the Plenary Chamber of Colombia’s Constitutional Court stated:
The precautionary principle is the cornerstone of a number of specific rules which are considered to have attained customary status and to be applicable in internal armed conflicts … Among these rules is … the obligation of the parties to a conflict to give effective advance warning of attacks which may affect the civilian population, unless circumstances do not permit. 
Colombia, Constitutional Court, Constitutional Case No. C-291/07, Judgment of 25 April 2007, p. 99.
[footnote in original omitted]