Digression: Just what is XML?
n It's a markup language used for annotating text
n It is concerned with logical structure
to identify sections, titles, section headers, chapters,
n It is not concerned with appearance
you say 'this is a subtitle'
not 'this is in bold, 14pt, centered'
you say 'this is an example'
not 'this is in verbatim, indented by 5pts, ragged