Or, you can take a look here:
We’re dropping the “fedora” vendor tag from all .desktop files for Fedora 19. If you maintain or co-maintain a package on this list that isn’t done yet, please take care of it. If you’re a Provenpackager, start with packages you’re familiar with, use, or otherwise care about, and then do others as you’re able.
You’ll have my undying gratitude, and that of the others who’ve worked on this. It might not be the most fun thing you work on today, but at least it’s tedious!