Related Rule
China
Practice Relating to Rule 46. Orders or Threats That No Quarter Will Be Given
China’s Law Governing the Trial of War Criminals (1946) provides that “ordering wholesale slaughter” constitutes a war crime. 
China, Law Governing the Trial of War Criminals, 1946, Article 3(14).
At some point during the Chinese civil war, the People’s Liberation Army (PLA) headquarters made an announcement stating that the PLA would not kill any officers or soldiers of the Nationalist Army who laid down arms. According to the Report on the Practice of China, the policy was implemented in practice. 
China, Announcement of the People’s Liberation Army, 10 October 1947, Selected Works of Mao Zedong, Vol. 4, The People’s Press, Beijing, p. 1238; Report on the Practice of China, 1997, Chapter 2.1.