IDN (Internationalized Domain Name) — domain starting from prefix «XN--»,
that may be displayed in the address bar as a set of characters from national scripts.

Example: domain «xn--d1acufc.su» represents «домен.su»
domain «xn--b1alf1j.net» represents «київ.net»
domain «xn--jgbpi6aq.com» represents «دطجغؤ.com»


Learn more about IDN registration of .SU domains (in Russian)
Learn more about IDN registration of .NET, .COM, .ORG, .CC, .TV, .NAME, .TEL domains