Règle correspondante
Greece
Practice Relating to Rule 65. Perfidy
Section J. Simulation of protected status by using flags or military emblems, insignia or uniforms of neutral or other States not party to the conflict
The Hellenic Navy’s International Law Manual (1995) provides that “the misuse of … the uniform and insignia of other states” constitutes perfidy. 
Greece, International Law Manual, Hellenic Navy General Staff, Directorate A2, Division IV, 1995, Chapter 5, § 4.