Forum OpenACS Development: Re: Checks for HTML standard compliance
anyhow, i've added quotes to the HTML attributes of the admin pages of acs-subsite were i found it missing, since for variable attribute values omitting quotes is always dangerous.
Therefore, i've implemented some support to capture the server output optionally  and fixed with that tool a few more validation problems of the admin pages. The problem with the site-map page is actually a nasty one, since the old code implemented a form starting in one table cell and ending in another one, which is invalid HTML. The fixed version  does not look exactly as before, but i think it is still sufficiently easy to understand. Other options would be to start the form before a <tr>, but i have no idea to achieve this with the list template.
Anyway, I have looked at your technique to log ns_return and maybe I will come up with something to reduce some passages.
I've set up a wiki page  for the pages I've fixed (and checked) so far to avoid duplication of work. please update this page as well (also, everybody else is invited to help). I found as well several public pages which needed some fixing.