Often Word documents contain preformatted, monospaced
text, as in a text screenshot or an extract of program
code. These should be recognized by wvHtml and output
as 'PRE' sections in HTML.
(A block of preformatted text could be identified by
having a monospaced font like Courier New, perhaps long
sequences of space characters used for indentation, and
hard newlines at the end of each line.)
At the moment PRE is not used so any spaces used for
indentation and formatting are lost.