It's my understanding that the muslims have a tier system of those they take over. If you don't convert, then you must submit and are a second class "citizen". But for those who don't even submit get a mark (something like a tattoo?) and are considered a slave. Then there are those who oppose them and are just get killed. Am I mistaken about this? I've had it in my mind that this is the mark of the beast the Bible refers to.