Of course, you normally would not be printing the mailmerge main document.
If you execute the merge, the document that is printed or created will not
have any field codes in it.
I am not sure why the action of printing the document is causing the field
codes to be displayed in the mail merge main document, if they were not
displayed before printing. However using Alt+F9 will toggle off the display
of field codes.
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Hope this helps.
Please reply to the newsgroup unless you wish to avail yourself of my
services on a paid consulting basis.
Doug Robbins - Word MVP