You can add watermarking to your mapping data by adding a Watermark tag to the UI Configuration file.
Sadly, to add solid watermarking to your data you need to provide 2 images :
Flash Player 8 and above : A transparent image (ex.: png) that will be overlayed (OFM doesn't tile, so make your image big enough!)
Flash Player 7 and below : A non-transparent image must be used, since there is no way to externally load a transparent image on these players. The image will be set to an alpha level of 10% to provide watermarking.
The resulting tag may look like this :
<Watermark>
<Transparent>watermerk.png</Transparent>
<NonTransparent>aerogrid.jpg</NonTransparent>
</Watermark>