The categories are
The charter of the committee states "[t]he purpose of the Committee is to identify and lessen or remove issues caused by license proliferation", which is a good thing, IMHO. I'm fed up with the recent trend that every company or organization invents their own "open source" license (often I would not even consider such licenses remotely open of free, but that's another issue).
In total, the report categorizes 59 licenses into the above categories. I'm sure most people would agree that such a huge amount of licenses is totally useless and only creates confusion and problems. Please, if you have to decide on a Free Software license one of these days, choose a major, well-known one. Or even better, if you currently use a non-standard license in one of your projects, please consider switching to a more streamline license which fits your needs. Thanks!