Thanks, Gaz!
Yeah, some places have belts and some use grades (1st, 2nd, 3rd and maybe 4th). The higher the grade, the more advanced the Kravist. For example, you don't get to do weapons training until you're third grade.
But the truth of it is that sort of thing is really downplayed. My instructor has only talked about grades or belts when telling stories about other Kravists. He hasn't mentioned it even once when talking about the class.
I haven't come right out and stated it yet, but if you go to a Krav instructor and he even mentions the idea of belts or grades during your initial consultation, you should probably just leave.
So far, "black belt factories" in Krav Maga are hard to find, but they're starting to pop-up. Take taekwondo for example. Most taekwondo dojos (or whatever they call them) are nothing more than places to buy black belts. It takes some work to find a solid taekwondo instructor.
In the class, it's usually easy to tell who are the more experience students. You can tell from physical conditioning and technique.
Out in the world, Kravists settle it the old Navy way: First one to die, loses.