The surrender gesture seems to be obvious to us - you drop your weapon, put your hands up and maybe drop to your knees or even prostrate yourself.
But were those gestures universal across the globe in the past? Were there situations, when soldiers continue to attack surrendering enemies not because of the "blood lust" or the "take no prisoners" order but simply because they didn't understand, that their opponent gave up fighting?
I have vague recollection of such instances during the Kosciuszko uprising 1794, where Polish peasants didn't understand surrender gestures made by Russian soldiers and Rommel's complains about the brutality of New Zealand Maoris killing surrendering German soldiers *, but I can't bring any evidence here.
In the "white flag" article on Wikipedia, we can read that
Before [the introduction of the white flag], Roman armies would surrender by holding their shields above their heads
This gesture would definitely be lost on many other cultures, probably even ones existing at the same time in Europe.
This was during conversation between Erwin Rommel and the captured NZ officer George H Clifton where the German general berates the Kiwis for their "gangster" tactics in killing unarmed prisoners of war after what must have been the Breakout at Minqar Qaim, for which the Clifton replied that the massacre was due to their being a "large number of Maoris in the Division".