Hi Luise,
No, formfields as used in a protected document are not compatible with
mailmerge. If the data to go into those fields is the same for all of the
records, then it could be entered directly into the mailmerge maindocument,
or by the use of formfields in that document (in that case, before executing
the merge, unprotect the document, use Ctrl+A to select everything and then
press Ctrl+Shift+F9 to unling the fields)
If the data to go in the fields is different for each record then the data
source is the obvious place to enter it.

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Hope this helps
Doug Robbins - Word MVP
>I have a main document containing Text Form Fields for the
> users to fill in. After the merge the text form fields
> have disappeared. Is there a way to retain those after a
> merge?
> thank you,
> Luise