make.valid.html — Attempt to make sure the HTML output is valid HTML
If make.valid.html is true, the stylesheets take extra effort to ensure that the resulting HTML is valid. This may mean that some para tags are translated into HTML divs or that other substitutions occur.
This parameter is different from html.cleanup because it changes the resulting markup; it does not use extension functions to manipulate result-tree-fragments and is therefore applicable to any XSLT processor.