Règle correspondante
Practice Relating to Rule 8. Definition of Military Objectives
Section A. General
Belgium’s Law of War Manual (1983) states:
Considered as military objectives are:
1) Persons: combatants
2) Objects: a) objects which by their nature, location, purpose or use make an effective contribution to military action
b) whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage
3) Places: every defended position. This does not necessarily mean that it must be reinforced: it is sufficient that enemy troops go through it, or that it is protected by mine fields, or that its access is closed by artillery fire. 
Belgium, Droit Pénal et Disciplinaire Militaire et Droit de la Guerre, Deuxième Partie, Droit de la Guerre, Ecole Royale Militaire, par J. Maes, Chargé de cours, Avocat-général près la Cour Militaire, D/1983/1187/029, 1983, p. 27.
Belgium’s Regulations on the Tactical Use of Large Units (1994) states: “An objective is the final goal of an action. It is defined as either an area of land of tactical importance or as enemy elements that have to be destroyed or neutralized.” 
Belgium, L’Emploi Tactique des Grandes Unités, Règlement G 119, Ministère de la Défense Nationale, Etat-Major Général, Force Terrestre, Sections Operations et Entraînement, 1994 (édition provisoire), § 210.