So, I did a bit more research, because learning is always a good thing. And I found this blog, that has a pretty good breakdown of GNPs. As well as this FAQ from aetherlumina. The FAQ is long, and I've not taken it all in as of yet. So far, I feel like it is good information, please correct me if I'm off base about the links though.
As an aside, I found this article on Slate in regard to Mandarin Chinese GNPs.