I was looking for this myself a while back and it seems they indeed no longer use the codes for US but zip codes. I had to format it as follows for it to work. My state is PA and zip is 19063, so substitute with yours:
HTC Hermes / ATT 8525
Super fast and stable!
Microsoft rule in the mobile market, much like the giant dinosaurs … more
18 Sep 2014
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?