Related Rule
South Africa
Practice Relating to Rule 6. Civilians’ Loss of Protection from Attack
South Africa’s LOAC Manual (1996) states: “If persons identified as civilians engage the armed forces, then they are regarded as unlawful combatants and may be treated under law as criminals.” 
South Africa, Presentation on the South African Approach to International Humanitarian Law, Appendix A, Chapter 4: International Humanitarian Law (The Law of Armed Conflict), National Defence Force, 1996, § 28(b). This manual is also included in Chapter 4 of the Draft Civic Education Manual of 1997.
South Africa’s LOAC Manual (1996) contains a rule identical to that in Article 50(1) of the 1977 Additional Protocol I. 
South Africa, Presentation on the South African Approach to International Humanitarian Law, Appendix A, Chapter 4: International Humanitarian Law (The Law of Armed Conflict), National Defence Force, 1996, § 24(c). This manual is also included in Chapter 4 of the Draft Civic Education Manual of 1997.
South Africa’s Revised Civic Education Manual (2004) states: “In cases of doubt as to whether a person is a civilian or not, that person shall be considered to be a civilian.” 
South Africa, Revised Civic Education Manual, South African National Defence Force, 2004, Chapter 4, § 47(c).