This year I am teaching my Electronic Text and Publishing course in
XML rather than SGML for the first time, and I came across a few
oddities in "A Gentle Introduction to XML".

- DTD is explained consistently as Document Type Declaration (pp. 6
ff. in the .pdf).
- "we must provide declarations for both <stanza> and <line> elements,
even though in a given document we know that only one will appear"
should probably read "we must provide declarations for both <stanza>
and <couplet> elements, even though in a given document we know that
only one will appear" (p. 20).
- "both the default TEI namespace and the additional gram namespace
apply to all elements in the document since they are declared on the
root element" seems to me (with my shaky grasp of such technical
matters) to be a bit misleading. Either <line> should be explicitly
elevated to root status (the example occurs in the discussion of a
hypothetical "verse" dtd, in which it would not be the root element),
or the example itself should be rewritten, to have the gram namespace
declared on the root element verse (pp. 22-23).

Adriaan van der Weel
Leiden Centre for the Book / Electronic Text Centre Leiden