Related Rule
Practice relating to Rule 66. Non-Hostile Contacts between the Parties to the Conflict
Section B. Use of the white flag of truce
The Code of Ethics (1991) of the Philippines stresses that the white flag of truce is a “worldwide custom used to signal the temporary cessation of hostilities between warring parties”. 
Philippines, Armed Forces of the Philippines Code of Ethics, 1991, Article 5, Section 2(4.5).