toggling-field-codes-in-microsoft-word

After you insert a Merge field into a Microsoft Word Document; you will see the name of the field ("Last Name" for example)

If  you want to see the Field code associated with that field; right-click the field and select Toggle Field Codes.

You will then see something similar to the following:

If you want to toggle field codes for all your merge fields; press Alt-F9 on your keyboard.

This will reveal the codes for all merge fields in your document.