Related Rule
Practice Relating to Rule 128. Release and Return of Persons Deprived of Their Liberty
Section C. Exchange of prisoners
Canada’s Prisoner of War Handling and Detainees Manual (2004) states:
2. … PW [prisoner-of-war] exchange is outside the provisions of [the 1949 Geneva Convention III] and although in the past there have been instances of the exchange of PW, man for man, in the course of truces or temporary cessation in hostilities, such instances are likely to be the exception.
3. Canada will not engage in PW exchange without the specific authority of the CDS [Chief of the Defence Staff]. When such authority is granted, the exchange is to take place under the supervision of the Protecting Power or the ICRC. 
Canada, Prisoner of War Handling, Detainees, Interrogation and Tactical Questioning in International Operations, B-GJ-005-110/FP-020, National Defence Headquarters, 1 August 2004, § 3H02.2–3.