MARK BLETCHER
Well, many of them had particular tags of cloth on their arms which identified them.  Also really during that period, there was a clear polarity between the two sides.
 There was the battle between two sides and the term "witdoeke" is used for the one and comrades is often used for the other.  So it was fairly clear which were the two sides.  
 Also "witdoeke" tended to carry particular weapons, knives and panga's and sticks and so on and have these tags and so on.