[Fuzz]

While the concept of an unlawful combatant is included in the Third Geneva Convention, the phrase itself does not appear in the document.[1] Article 4 of Third Geneva Convention does describe categories under which a person may be entitled to POW status, and there are other international treaties that deny lawful combatant status for mercenaries and children. In the United States, the Military Commissions Act of 2006 codified the legal definition of this term and invested the U.S. President with broad discretion to determine whether a person may be designated an unlawful enemy combatant under United States law. The assumption that such a category as unlawful combatant exists is not contradicted by the findings of the International Criminal Tribunal for the Former Yugoslavia in the Celebici Judgment. The judgment quoted the 1958 International Committee of the Red Cross (ICRC) commentary on the Fourth Geneva Convention: Every person in enemy hands must be either a prisoner of war and, as such, be covered by the Third Convention; or a civilian covered by the Fourth Convention. Furthermore, "There is no intermediate status; nobody in enemy hands can be outside the law",[4] because in the opinion of the ICRC, "If civilians directly engage in hostilities, they are considered 'unlawful' or 'unprivileged' combatants or belligerents (the treaties of humanitarian law do not expressly contain these terms). They may be prosecuted under the domestic law of the detaining state for such action".[1][5]

https://en.wikipedia.org/wiki/Unlawful_combatant

This should clear up a few of the questions here.