When the default layout and output of the DocBook to PDF transformation needs to be customized, follow these steps:
You could start from a copy of the file [DocBook XSL directory]/fo/titlepage.templates.xml (for example, [OXYGEN-INSTALL-DIR]/frameworks/docbook/xsl/fo/titlepage.templates.xml) and customize it. More information about the spec file can be found here.
<xsl:import href="dir-name/mytitlepages.xsl"/>book/info/mediaobject structure of the XML document.