The top-level domain (TLD) you mentioned, XN—XHQ521B, is actually an Internationalized Domain Name (IDN) in ASCII compatible encoding format (also known as Punycode). Punycode is a method that enables ASCII character-only systems like Domain Name System (DNS) to handle domain names containing non-ASCII characters, which in this instance is an essential part of the global internet infrastructure.
The xn— prefix indicates that what follows is a Punycode string, which represents the Unicode characters of a hostname or domain name.
However, in your particular case, the Punycode string “XHQ521B” isn’t directly translatable into a readable domain name via a standard Punycode to Unicode translation. An example of direct conversion of a Punycode string to a Unicode domain is the Punycode domain name “xn—80akhbyknj4f”, which translates to “пример.испытание” in Russian, which means “example.test” in English.
So, the TLD: XN—XHQ521B appears to be non-standard.
For reference, in the IANA (Internet Assigned Numbers Authority), which is a department of ICANN (Internet Corporation for Assigned Names and Numbers), responsible for coordinating some of the key elements that keep the internet running smoothly, we can observe recognized TLDs, such as .com, .edu, .gov, .net, .org, and txt., along with country-specific TLDs like .uk, .fr, .jp, and .au, as well as more than 1000 new gTLDs like .xyz, .online, .site and .tech.
Information about encoding and support for IDNs within IANA and ICANN can be found in their IDN repository: https://data.iana.org/idn/tables/.
For Punycode translation and information, refer to The Network Working Group’s RFC 3492; a document that provides technical and organizational notes about the functioning of the Internet. It is available online at this link: https://tools.ietf.org/html/rfc3492.
The usage and details about the Punycode can also be found at the Mozilla Developer Network resource: https://developer.mozilla.org/en-US/docs/Glossary/Punycode.
Overall, while the notion of representing non-ASCII characters within domain names via Punycode is quite common, the specific implementation you’ve asked about doesn’t adhere to a universally recognizable format based on existing reputable sources such as IANA, ICANN, and the Network Working Group’s documentation.
