We have just published the new POWER Instruction Set Architecture (ISA) version 3.0. This new ISA supports the next generation POWER processors and continues the evolution over the previous ISA for Power architecture. It is the first generation of the architecture developed and released after the creation of the OpenPOWER Foundation.
This new Power ISA 3.0 has no longer optional categories, as well as separate server and embedded ISA architecture options. This new specification supports the entire range of implementations with no distinction.
The new Power ISA 3.0 can be downloaded here: http://ibm.biz/power-isa3.