IDN (Internationalized Domain Name) / Punycode

An IDN (internationalized domain name) is a domain that uses non-ASCII characters — münchen.de, 中国.cn, or an emoji domain — so names can be written in scripts beyond basic Latin. Because the DNS itself only handles ASCII, an IDN is encoded into a compatible ASCII string called Punycode, which always begins with the xn-- prefix (so münchen becomes xn--mnchen-3ya). Registries and registrars support IDNs at the TLD level, though they carry a known risk: visually similar characters enable homograph lookalikes used in phishing. An IDN is still an ordinary registered name underneath, so it can be tokenized and held in a wallet like any other domain. Sources: RFC 5890; ICANN IDN resources.