Règle correspondante
Canada
Practice Relating to Rule 10. Civilian Objects’ Loss of Protection from Attack
Section B. Situations of doubt as to the character of an object
Canada’s LOAC Manual (1999) states:
In the case of doubt as to whether an object which is normally dedicated to civilian purposes (such as a place of worship, a house or other dwelling, or a school) is being used to make an effective contribution to military action, it shall be presumed not to be so used. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 4-5, § 38.
Canada’s LOAC Manual (2001) states in its chapter on targeting:
In the case of doubt as to whether an object which is normally dedicated to civilian purposes (such as a place of worship, a house or other dwelling, or a school) is being used to make an effective contribution to military action, it shall be presumed not to be so used. 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 429.
Canada’s Use of Force Manual (2008), in a section entitled “Principles and rules governing the use of force that directly relates to the conduct of armed conflict”, states:
Doubt rule. A person or object must not be attacked unless there is a reasonable belief that the person or object to be attacked is a military objective. In cases of doubt, a person is presumed to be a civilian, and the use of an object normally dedicated to civilian purposes is presumed to be of a nature other than that constituting an effective contribution to military action, unless and until the contrary is established. 
Canada, Use of Force for CF Operations, Canadian Forces Joint Publication, Chief of the Defence Staff, B-GJ-005-501/FP-001, August 2008, § 112.3.