MD11 - bars can save a lot of trouble when dealing with petty officials and the military in some parts of Africa. The more stripes the merrier but I always used singles (whatever 'they' represent) and they usually worked just fine. A 'small' monetary gift of, say, $5.00 can be useful as well if the wheels start grinding to a halt in places like Kinshasa. Annoying but worth the lack of strife!
I agree with Perrin, having had the business end of an AK waved under my nose...