Related Rule
Syrian Arab Republic
Practice Relating to Rule 6. Civilians’ Loss of Protection from Attack
The Report on the Practice of the Syrian Arab Republic notes that the Syrian Arab Republic did not make any reservations to Article 51 of the 1977 Additional Protocol I and thus views the conditions stated in this Article as part of customary international law. 
Report on the Practice of the Syrian Arab Republic, 1997, Chapter 1.2.