Early last month, the UEFI Forum updated this spec:
_DSD (Device Specific Data) Implementation Guide, v1.1
http://www.uefi.org/sites/default/files/resources/_DSD-implementation-guide-toplevel-1_1.htm
The main thing added to the above HTML document was a pointer to this spec:
Click to access _DSD-hierarchical-data-extension-UUID-v1.pdf
It describes a new Hierarchical Properties Extension UUID. I don’t know much about _DSD, it has been around for a while, so not sure if this 1.1 change is interesting or not.
I wish UEFI Forum would announce updates to ACPI specs. There web site has multiple press/news pages and RSS feeds, only a few of them are operational.
More Information:
Firmware Security 