I'd suggest for the Help on Desktop Pages that you add the sentence on needing a fence to begin with. Especially since it's a frequently asked question.
The user would expect the rules to apply to portals, since they seem to be just like fences. So maybe that's another place to add guidance - right at the top under "New icon placement and auto-organizing". I like the portals feature and use them wherever possible. That helps keep desktop (C:\) size down and makes sure things are in the data drive (D:\) folders where I ultimately want them anyway. Of course it would be much better if the rules could be made to apply to portals, but I assume that's not reasonably possible.
Try using as standard user.
