role and title

If you're using xlink:simple, then the xlink:role and xlink:title attributes are simply role and title. For example:

<xlink:simple 
 xmlns:xlink="http://www.w3.org/XML/XLink/0.9"
 href="http://www.macfaq.com/personal.html"
 title="Elliotte Rusty Harold's personal home page" 
 role="information about the author of this book">
   <AUTHOR>Elliotte Rusty Harold</AUTHOR>
</xlink:simple>