There are some simple production issues that weren't addressed (e.g., Error! Source Reference Not Found.) when the materials were put together. This is a minor quality issue that can be addressed later, but it makes the content much harder to read, and provides an image of amateurism with respect to the content that is distracting.
Data TypesHeD claims conformance to ISO 21090 data types, but doesn't use the actual names given in 21090 in the elements, nor does it use the 21090 XML schema. It can thus only claim indirect conformance. What drives me crazy about this is that if you are going to use a standard, and refer people to that standard for details, changing it doesn't help anyone (even constraining it causes confusion, but that is often necessary).
The description of the data type content is purely an extraction from the schema, adding little value. It contains an image from the schema editor, and two tables, one for elements, and one for attributes which provide the element or attribute name, its datatype, cardinality, and whether the element is required or optional (which can be deterministically computed from cardinality).
HeD Expression LanguageNo. No. No. Please write on the board 1000 times (and you must write it with the pointy brackets):
<subject>I</subject> <verb>will</verb> <adverb>not</adverb> <verb>create</verb> <adjective>programming</adjective> <noun>languages</noun> <preposition>in</preposition> <noun>XML</noun>.
There's not enough in the guide for me to go much further, I now have to look at the examples and the schemas to see how this really works. That, in and of itself is pretty damning, because if I cannot figure out how to write one of these artifacts from the guide, then the guide has failed.