The file is declared as HTML 4.0 Transitional, but if you look at the tags the site uses it uses XHTML style tags with any unpaired tag ending in a /. So it appears to me that the site attempts to be XHTML, but declairs it self as HTML4 to prevent a poorly formated post from causing a strictly compliant browser from mis-rendering the whole page.
So it appears to me that the site attempts to be XHTML, but declairs it self as HTML4 to prevent a poorly formated post from causing a strictly compliant browser from mis-rendering the whole page.