In GnuPG VS-Desktop we have the text "VS-NfD compliant" (green) or "not VS-NfD compliant" (red) in the right corner of the status line in the main Kleopatra window. This indicates whether GnuPG VS-Desktop is installed in compliance with classified information requirements or not.

This is explained in the handbook which was compiled for the approval by the BSI.

This should be shortly explained in a tooltip which should (optimally) be configurable via a file.
See T7514: Draft: Kleopatra: Tooltip for the status "VS-NfD compliant" for the file to be used.

Text proposal ("VS-NfD Compliant" is a variable, alternate possibilities are: "EU Restricted", "NATO Restricted" and the German "VS-NfD konform"):
"This installation is VS-NfD Compliant." / "Diese Installation ist VS-NfD konform."

Negative variety:
"This installation is *not* VS-NfD Compliant. Do *not* use for VS-NfD Compliant data." / "Diese Installation ist *nicht* VS-NfD konform. *Nicht* für VS-NfD konforme Daten verwenden!"