Related Rule
Israel
Practice Relating to Rule 3. Definition of Combatants
According to Israel’s Manual on the Laws of War (1998), legal combatants are “soldiers serving in the army (regular and reserve) or in well-ordered militia forces (e.g. the SLA or the State National Guards in the United States)”. 
Israel, Laws of War in the Battlefield, Manual, Military Advocate General Headquarters, Military School, 1998, p. 47.
In its judgment in the Public Committee against Torture in Israel case in 2006, Israel’s High Court of Justice stated:
What makes a person a combatant? This category includes, of course, the armed forces. It also includes people who fulfill the following conditions (The Hague Regulations, §1):
“The laws, rights, and duties of war apply not only to armies, but also to militia and volunteer corps fulfilling the following conditions:
1. To be commanded by a person responsible for his subordinates;
2. To have a fixed distinctive emblem recognizable at a distance;
3. To carry arms openly; and
4. To conduct their operations in accordance with the laws and customs
of war.
…”
Article 13 of The First and Second Geneva Conventions and article 4 of The Third Geneva Convention repeat that wording (compare also article 43 of The First Protocol [1977 Additional Protocol I]). Those conditions are examined in the legal literature, as well as additional conditions which are deduced from the relevant conventions (see DINSTEIN, at p. 39). We need not discuss all of them, as the terrorist organizations from the area, and their members, do not fulfill the conditions for combatants (see GROSS, at p. 75). It will suffice to say that they have no fixed emblem recognizable at a distance, and they do not conduct their operations in accordance with the laws and customs of war. 
Israel, High Court of Justice, Public Committee against Torture in Israel case, Judgment, 14 December 2006, § 24.