Related Rule
France
Practice Relating to Rule 10. Civilian Objects’ Loss of Protection from Attack
France’s LOAC Summary Note (1992) states: “Civilian objects may not be attacked, unless they have become military targets.” 
France, Fiche de Synthèse sur les Règles Applicables dans les Conflits Armés, Note No. 432/DEF/EMA/OL.2/NP, Général de Corps d’Armée Voinot (pour l’Amiral Lanxade, Chef d’Etat-major des Armées), 1992, § 1.5.
France’s Penal Code (1992), as amended in 2010, states in its section on war crimes common to both international and non-international armed conflicts: “Intentionally launching attacks against civilian objects which are not military objectives is punishable by 15 years’ imprisonment.” 
France, Penal Code, 1992, as amended in 2010, Article 461-14.
France’s LOAC Manual (2001) states: “In case of doubt, an object usually affected to a civilian use must be considered as civilian and shall not be attacked.” 
France, Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, p. 90.