The 'idn --help' output contains old-style `quotes'. Between 1995 and 2000, the world changed to use fonts based on ISO-8859-1 or Unicode, instead of fonts based on US-ASCII [1]. Old-style `quotes' look very ancient by now.
I would suggest to modernize it, althrough it will mean a bit of work for the translators. Bruno [1] https://www.cl.cam.ac.uk/~mgk25/ucs/quotes.html
