Related Rule
India
Practice Relating to Rule 3. Definition of Combatants
India’s Army Training Note (1995) defines the term “terrorist” as:
a person who indulges in wanton killing of persons or involves in violence or in the disruption of services or means of communications essential to the community or in damaging property with a view to putting the public or any section of the public in fear, or affecting adversely the harmony between different religious, social, linguistic groups or the sovereignty and integrity of a nation. 
India, Army Training Note, Chief of Staff, Army Training Command, Ministry of Defence, Government of India, 1995, p. 4/16, § 35.
According to the Report on the Practice of India, this definition is “intended to help the armed forces to identify the ‘terrorists’ who may be treated as combatants if the situation can be likened to an internal conflict”. 
Report on the Practice of India, 1998, Chapter 1.1.
In 1975, the Supreme Court of India held that civilian employees of the armed forces are “integral to the armed forces as it is their duty to follow or accompany the armed personnel on active service or in camp or on the march”. They are however “non-combatants”. The Court further stated: “all persons not being members of the armed forces, but attached to or employed with or following the regular army shall be subject to the military law”. 
India, Supreme Court, Nair case, Judgment, 20 November 1975, §§ (b) and (c).