Word can highlight the field. There are three options: off, highlight when selected, and highlight always. This feature is available in all versions since Word 97 (perhaps since Word 6.0). In Word 2007 you can turn it on by
- click the Application Button
- click Word Options
- select the Advanced category
- scroll down to the Show Document Content section
- change the Field Shading setting to Always
In Word 2003 and earlier the feature is also called Field Shading.
- select Tools > Options
- select the View tab
- change the Field Shading setting to Always
The shading is not printed so you don't have to turn this off.