Well, in all honesty, I think the US, the Brits and the Commonwealth, and maybe the French have been really hard and fast about the "don't shoot at the guys silly enough to wear red crosses" rule. As for how it all works...

And an M-16 isn't a violation of the thing that says that medics can't carry rifles, because that rule DOES allow medic to carry carbines and other defensive weapons. :P
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-IronRaven

When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.