Gyroscopic Investing

I've never quite grasped the meaning of the term "Gold Bullion Comex Eligible".  I know it's different than "registered" Comex bullion and can't be used in the delivery process.  What I'm confused about is why does it have to be Comex gold in the first place?  Why does Comex have to be involved at all?  Aren't there storage vaults around that don't have anything to do with Comex?  Sorry for the string of questions... I sound like a DA. 

Interesting question. I just came across this article which discusses the problems with Comex being overwhelmed by orders. And if Comex is already overwhelmed, imagine the problems if commodities really became hot...

http://www.huffingtonpost.com/nathan-le ... 16896.html

It seems that Comex may have some real problems.