ACTION 2023-10-17-b; names are case-sensitive

Add to the end of:

A name starts with a letter or underscore, and continues with a letter, 
digit, underscore, a small number of punctuation characters, and the 
Unicode combiner characters; Unicode classes are used to define the sets of 
characters used, for instance, for letters and digits. This is close to, 
but not identical with the XML definition of a name; it is the grammar 
author's responsibility to ensure that all serialized names match the 
requirements for an XML name [XML <https://invisiblexml.org/1.0/#xml> ].

the sentence: Names are case-sensitive.

Steven