IADS programs used the frame tag to achieve precisely the same effect in the early nineties. It would be somewhat Karmic to see Unisys used in a prior art argument. The US Army might prove to be a tough problem for Sun lawyers.
Civil servants are relentless customers.
Ekam sat.h, Vipraah bahudhaa vadanti. It's also come to light in this draft that Sun claims a patent on some of the technologies needed to implement XPointer.