http://tools.ietf.org/html/rfc3492#section-6.2


www.xn--champs-lyses-hebd.com		->	www.champs-élysées.com

user@xn--champs-lyses-hebd.com		->	user@champs-élysées.com

www.xn--pre-nol-2xa6a.net		->	www.père-noël.net

www.xn--y3h.com		->	www.☎.com