[Parody]

My recommendation to the RW folks is to explicitly say that you must add tags to the domains that start empty in order to use them. Compare how an empty domain is used to how one that starts with the Pathfinder items is used (almost the same if you're not using Pathfinder) to one that's more generic.

In the future I believe they expect most people to base their campaigns on shared system campaigns that come with a baseline set of information for the system, much like you buy game systems in Hero Lab. When you start with at least a system realm many of the empty global tag domains are going to have entries already.

I'd do this in layers, so there might be a Pathfinder base realm with basic rules, races, classes, items, maybe generic NPCs from those books, and such. On top of that you'd have a Golarion campaign world realm with locations, NPCs, items, prestige classes, and whatnot added to the base realm. Then your Rise of the Runelords AP realm would be built on top of that. This lets GMs start with what they intend to use.

Aside: This sort of design has been an issue for me. I've been hesitant to start adding my own adventures to my Paranoia realm because I don't really want to go back and redo the whole mess to split the base system and my creations once sharing becomes available. Once upon a time I'd said that we're all likely to have to either throw out or redo our work once sharing was available. I don't really want to do that, but it still seems likely. :(