Related Rule
Ukraine
Practice Relating to Rule 4. Definition of Armed Forces
Ukraine’s IHL Manual (2004) states:
The armed forces of a belligerent State (Party) consist of all organized armed forces which are under a command responsible to that State (Party) for the conduct of its subordinates.
Armed forces shall be subject to an internal disciplinary system which shall enforce compliance with the rules of international humanitarian law.
Armed forces consist of combatants (those who fight) and medical and religious personnel (non-combatants). 
Ukraine, Manual on the Application of IHL Rules, Ministry of Defence, 11 September 2004, § 1.2.21.
In 2009, in the War veterans case which concerned the question of whether members of the Ukrainian Insurgent Army are entitled to social security benefits as war veterans, Ukraine’s Kyiv Administrative Court of Appeal upheld the decision of the lower court. The Court held:
The court of first instance concluded that in compliance with paragraph 1 of article 43 of the Additional Protocol to [the] Geneva Conventions dated 12 August 1949 relating to the Protection of Victims of International Armed Conflicts (Protocol I), dated 8 June 1977, signed by Ukraine on 12 December 1977, ratified in August 1989 and entered into force on 25 July 1990, armed forces of the Party to a conflict consist of all organized armed forces, groups and units which are under a command responsible to that Party for the conduct or its subordinates, even if that Party is represented by a government or an authority not recognized by an adverse Party. …
… Not only a State is regarded as a belligerent party … [Pursuant to] article 1 of the … [1907 Hague] Regulation[s], the laws, rights, and duties of war apply not only to armies, but also to militia and volunteer [corps] if they fulfil the list of conditions, e.g. they should conduct their operations in accordance with the laws and customs of war.
… [T]he panel of judges, [pursuant to] article 200 of the Code of Administrative Court Procedure of Ukraine, decided to … [uphold] the judgment of the court of first instance … without any alterations. 
Ukraine, Kyiv Administrative Court of Appeal, War veterans case, Decision, 17 February 2009.