Add water mark in POs Print Report which are in Draft

We follow-up (Doc ID 420671.1) trying to customize it according to our requirement

But we just what to know where the below mentioned piece of code should be written in XSL Stylesheet to make it as watermark?

<fo:inline>

<fo :external-graphic content-width="248pt" content-height="33pt"
src="url('http://test.xx.xxxxxxe.com:10403/<oa media directory path>/yellow_circle.gif')" />
</fo:inline>