Unicode characters enable domain name variations

Unicode includes separate symbols for TradeMark, Service Mark, and Prescriptions. The Telephone symbol and Numero Sign are single characters found among the 'Letterlike Symbols' in Unicode. The .tel and .no domains are Top-Level-Domains on the Domain Name System. A contact site using the Telephone symbol as a TLD can be written as https://edent.℡/. The Norwegian domain name registry NORID can be accessed at https://www.norid.№/.

Unicode characters can be used anywhere in a domain name, not just for TLDs. The URL https://𝐞𝐱𝐚𝐦𝐩𝐥𝐞.𝐜𝐨𝐦/ uses Math Bold characters for the domain name. The URL https://𝖊𝖝𝖆𝖒𝖕𝖑𝖊.𝖈𝖔𝖒/ uses Fraktur characters for the domain name. The URL https://🄴🅇🄰🄼🄿🄻🄴.🄲🄾🄼/ uses Math Squared characters for the domain name. The URL https://ⓔⓧⓐⓜⓟⓛⓔ.ⓒⓞⓜ/ uses Circled characters for the domain name.

The conversion of Unicode characters to valid domain names is performed by the browser using the IDNA2008 process. The author tested the functionality by asking people on Twitter if they could access a website using a .℡ domain. The domain hack works on command line tools like wget and curl. Sites like Twitter and Facebook do not recognize Unicode domain hacks as valid URLs and refuse to auto-link them. Some command line tools like dig and host do not understand Unicode domain hacks. The dig command returns an NXDOMAIN status when queried for a domain with a Unicode character like edent.℡. Unicode domain hacks may be useful for evading URL filters. The Unicode character ㏕ normalizes down to the US Military TLD.