I would reword "Additions" to "Changes" and explicitly state that these fields concern the new USB 3.0 hub descriptor format, which is different and exclusively applies to SuperSpeed hubs.
This bit fields are actually additions to USB 3.0 framework. These fields are not defined in USB 2.0 specs, or else they are reserved there. If you insist i can modify this as suggested.
Yes, okay, I think we mean the same thing here. I just wanted to point out that the USB 3.0 port status is actually a completely different thing from the USB 2.0 port status (which is still valid for non-SuperSpeed hubs in USB 3.0 environments, even though the spec hasn't printed it out again). They did not just *add* a few bits to the old status bit field, they actually *changed* existing bits (not just reserved ones)... e.g. bit 9 means LOW_SPEED for USB 2.0 hubs but PORT_POWER for SuperSpeed hubs. I found this very confusing when I first read it, so I thought it might be worth making it extra obvious through comments.