I just created a policies.json file in the appropriate distribution folder with ONE policiy, then restarted the browser, and now the browser shows: The browser is managed by your organisation. ("Der Browser wird durch Ihre Organisation verwaltet." in German.) Now the question occured to me: Has this any effect on the changes I made before manually in the about:config section, or in the settings UI, other than the one change by the one policy I put in the policies.json? Firefox 91.3.0esr (64-Bit)