Bug#351858: not OK to make invalid HTML

[Dan Jacobson <jidanni@jidanni.org>]

In http://localhost/manual/mod/mod_autoindex.html
  SuppressIcon (Apache 2.0.23 and later)
    This will suppress the icon in fancy indexing listings. Combining
    both SuppressIcon and SuppressRules yields proper HTML 3.2 output,
    which by the final specification prohibits img and hr elements
    from the pre block (used to format FancyIndexed listings.)

So apparently the authors know that they output im"proper" (invalid)
HTML.

They should tighten their ship to always output valid HTML. Perhaps
using html4/strict.dtd too.