Related Rule
Canada
Practice Relating to Rule 117. Accounting for Missing Persons
Section D. Right of the families to know the fate of their relatives
Canada’s LOAC Manual (1999) contains provisions stipulating that “belligerents must facilitate enquiries by members of families dispersed as the result of war with the object of renewing contact between them”. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 11-3, § 28.