You got it all right, Starryk. But let's see. There are measure tapes, right? And an established way to measure breasts, right? So you just need to establish a parameter to succesfully fit the model into that category. Big Boobs will be at least: a C, a D, a DD? Once you establish the parameter it's easy to fit everything in place. But the weirdest part, still, is that on the first card of any given model, you stablished, supposedly, the categories the model will be presented and announced as a product. You already decided "This girl is Big Boobs, Asian, Red-haired..." Whatever. You can't announce a black car as a compact one day and announce the exactly same car in white the other day saying that it is a truck. Or can you? It's a mystery. So, why?
Keep wondering.