IDN means Internationalized Domain Name. IDNs are domain names that include local language characters, such as
Gandi already has 50 extensions that support IDNs.
IDNs can be registered at Gandi for the following extensions (click for more info):
Technically, the “special” characters are encoded using a conversion table. This is why an IDN domain name will begin with the four characters
xn––. For example:
xn-–bb-bjab.eu. (This is also why you can't otherwise register domain names with hyphens in the third and fourth position.)
xn––version of your domain name when logging into Gandi's webmail or when configuring your email program.