I believe each brand has their proprietary types of carbon fiber materials. So it is hard to compare between brands. You can compare weights between different brands in terms of framesets, and that will give you an idea of the "quality" of the carbon they use. However, frame shape and design comes into it as well, so it is really comparing apples to oranges. Trek's Domane might be a lighter frame than Specialized's competitor, but it might also flex more or be more fragile, so it is hard to know what you are getting.

The only sensible thing you can compare is the different types of carbon in the same manufacturer and the same frame shape. I know Trek uses different carbon types in their frames they call OCLV 700, 400, 300. Higher numbers being stiffer and stronger for the same weight, or lighter weight for the same stiffness and strength.

I think at a certain point you have to take manufacturers at their word about how "stiff light and strong" their frames are, because they give you very little real verifiable information about them. All those materials designations are also just marketing up to a certain point.