Adding a Watermark in DITA Map to XHTML Output

To add a watermark to the XHTML output of a DITA map transformation, follow these steps:

Create a custom CSS stylesheet that includes the watermark image, as in the following example:
```
body {
 background-image: url(MyWatermarkImage.png);
}
```
Edit a DITA Map XHTML transformation scenario and in the Parameters tab set the value of the args.css parameter as the path to your watermark image.
Set the value of the args.copycss parameter to yes.
Apply the transformation scenario.
Copy the watermark image in the output directory of the transformation scenario, next to the CSS file created in step 1.