When I say "without a region," I mean "don't show up on /rmap, /bmap or /cmap." They also tend to be areas where party invites cannot be sent into or out of, only within (whereas normally you can send invites across areas within the same region, or between areas anywhere on /cmap, but that last one is probably just a bug).

I suspect it's a pretty good indication of when you've crossed from one server to another.