XMI13 — Combined document structure unclear

Though the document does say it builds on XMI 1.1 it's not clear how the 2
specs are to be read together; neither does it seem complete as a new
replacement XMI specification (e.g. it's missing some of the introduction
and usage scenarios that are in the 1.1 spec). [NB should it not build on
the "formal/" XMI 1.1 specification not the submitted one?]
Neither the cumbersome name for the specification (which should be changed)
and the headings used for the document do not help: for example section 4
applies to XMI 2.0 schemas only.
It might have been clearer to have 2 separate specifications: an add-on to
XMI 1.1 that just added XMI 1.1-compliant Schema generation. And,
separately, a complete stand-alone specification for XMI 2.0.

see above