I looked at:
and found that
1. "plain text document" is not in the gramps.pot file, and not translatable.
However, it is translated "outside" of GRAMPS.
I also think that "Plain Text" in AsciiDoc.py is not used as it seems to be
replaced by "plain text document"?
2. src/docgen/PdfDoc.py is not in po/POTFILES.in
Any reason for this?