Related Rule
Côte d’Ivoire
Practice Relating to Rule 19. Control during the Execution of Attacks
Côte d’Ivoire’s Teaching Manual (2007) provides in Book III, Volume 1 (Instruction of first-year trainee officers):
IV.1.2. Obligations in the execution of the attack
The force leading the attack must be ready to cancel, suspend or adapt a planned attack if it becomes apparent that the objective is not a military one or is subject to special protection or that the attack may be expected to cause incidental civilian damage which would probably be excessive in relation to the concrete and direct military advantage anticipated (principle of proportionality). 
Côte d’Ivoire, Droit de la guerre, Manuel d’instruction, Livre III, Tome 1: Instruction de l’élève officier d’active de 1ère année, Manuel de l’élève, Ministère de la Défense, Forces Armées Nationales, November 2007, p. 49; see also Droit de la guerre, Manuel d’instruction, Livre IV: Instruction du chef de section et du commandant de compagnie, Manuel de l’élève, Ministère de la Défense, Forces Armées Nationales, November 2007, p. 71.
In Book IV (Instruction of heads of division and company commanders), the Teaching Manual provides:
The proportionality test is as follows: can the attack be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, excessive in relation to the concrete and direct military advantage anticipated? If the answer is “yes”, the attack must be cancelled or postponed. The proportionality test must be used for the selection of every objective. 
Côte d’Ivoire, Droit de la guerre, Manuel d’instruction, Livre IV: Instruction du chef de section et du commandant de compagnie, Manuel de l’élève, Ministère de la Défense, Forces Armées Nationales, November 2007, pp. 28 and 29.