IDN, or internationalized domain name, allows the use of characters outside the American Standard Code for Information Interchange (ASCII) in domain names, such as letters from the Estonian or Russian alphabet.
How does IDN work?
To display internationalized domain names, the IDNA standard is used—a mechanism for rendering characters outside of the ASCII set in domain names. In nameserver systems, IDNs are stored as ASCII-encoded strings using “Punycode”.
Why does my email address with special characters look so strange?
The normal form of the internationalized domain name “käbi.ee” is “xn--kbi-qla.ee”. Whether the name is shown in its original or encoded form depends on the application displaying it. Some websites and email clients do not fully support the IDNA standard yet and may show the ASCII version instead.
