And thanks IS given to Cisco for their keeping it around to able to be found.  Seriously...it's appreciated. 

Yep.  And it needed to be shared.  You kind of need to have this document to understand some of the Specification if you're implementing a system using it between USXGMII so you don't foot-gun yourself with some aspects of it.  Happy to have helped t...

For the latecomers...you need to be a member of this community and go into the ARCHIVED documents section of the network programming- it's no longer, "relevant," but they have thoughtfully archived it under USXGMII there.It covers, in large, the spec...