Related Rule
Ukraine
Practice Relating to Rule 5. Definition of Civilians
Ukraine’s IHL Manual (2004) states:
A civilian is any person who finds himself/herself in the zone of warfare, is not a member of armed forces and refrains from any act of hostility. In case of doubt whether a person is a civilian, that person shall be considered to be a civilian.
The civilian population comprises all persons who are civilians. The presence within the civilian population of individuals who do not come within the definition of civilians does not deprive the population of its civilian character and of its protection under international humanitarian law. 
Ukraine, Manual on the Application of IHL Rules, Ministry of Defence, 11 September 2004, § 1.2.32.