Related Rule
Ukraine
Practice Relating to Rule 117. Accounting for Missing Persons
Ukraine’s IHL Manual (2004) states:
“Missing persons” mean persons who are missing during hostilities and whose whereabouts are unknown.
Regarding such persons … as soon as circumstances permit (at the latest from the end of active hostilities) each Party to the conflict shall search for the persons who have been reported missing by an adverse Party. 
Ukraine, Manual on the Application of IHL Rules, Ministry of Defence, 11 September 2004, § 1.2.29.
Ukraine’s IHL Manual (2004) states:
Requests for search from one Party to another in accordance with the provisions of part V of the Geneva Convention Relative to the Treatment of Prisoners of War of 12 August 1949 and part III of the Geneva Convention Relative to the Protection of Civilian Persons in Time of War of 12 August 1949 shall be transmitted through the National Tracing Agencies and the Central Tracing Agency of the International Committee of the Red Cross. 
Ukraine, Manual on the Application of IHL Rules, Ministry of Defence, 11 September 2004, § 1.2.29.
Ukraine’s IHL Manual (2004) states:
“Missing persons” mean persons who are missing during hostilities and whose whereabouts are unknown.
Regarding such persons, the Parties to an armed conflict shall be primarily guided by the right of the families to know about the fate of their relatives. 
Ukraine, Manual on the Application of IHL Rules, Ministry of Defence, 11 September 2004, § 1.2.29.