UML Model of XML Schema-Related Concepts

Hi Folks,

I've attached a one-page PDF file expressing a UML class diagram of various
XML Schema-related concepts. I would appreciate comments regarding its
correctness.

Background
==========
I work with a number of standards organizations on XML-related activities.
I've observed that progress often stalls as a result of participants using
imprecise terms when referring to various W3C XML Schema Definition Language
(XSDL)-related concepts. Participants frequently use terms more broadly,
narrowly, or differently than defined by the W3C. Participants also
frequently use their own "common sense" terms to refer to concepts for which
the W3C has defined a term. At times it seems that discussions degenerate
into a technical jargon fog. In my efforts to encourage using more precise
language among standards participants, I discovered that many XSDL-related
concepts needed to be understood in relation to one another--hence the UML
model.

Best regards,
Jim Wilson
CIDX Chief Architect