When converting HTML into DOCX and PDF documents, and using the address parameter relative URLs will be automatically converted into their absolute URL equivalents. To stop this happening links must be prepended with grabzitlink://
So, for instance, to stop the below link is converted to an absolute link.
<a href="test.html">Test Page</a>
The link must then be changed, as shown below.
<a href="grabzitlink://test.html">Test Page</a>