While Word offers a variety of options for watermark text, most of which will suit the average users needs, you are not limited to the text specified in the Printed Watermark dialog box. In fact, you can use any text you would like for your documents watermark.
To use custom text for your watermark, follow the same steps for creating a text watermark.
Instead of selecting text from the Text drop-down box, simply type in your custom text. When you click OK, the your custom text will appear as a watermark.