Allegro Serve - XHTML compliant code

Hello:

I recently downloaded the Allegro Server and after going through the
tutorials and examples my impression is that of an excellent example of
practical  LISP programming. I´m really looking forward to study the code
more closely. 
My current LISP skills are limited although I´ve worked with html and
dynamic webpages for several years. One thing about the Allegro Serve
project stroke me: Everything, protocols etc. seems to be up to date,
nevertheless the htmlgen produces html syntax which is not compliant with
XHTML 1.0 version, by generating attribute names in upper-case and
unterminated empty elements like <br> and <img>. Is there any particular
reason for this disposition?
My guess is that it should be relatively easy to correct the output syntax,
furthermore the required syntax for XHTML (lower-case and terminated empty
elements like <br /> does not exclude a correct code generation in HTLM4.1