Domain hacks with unusual Unicode characters

Unicode contains a range of symbols which don't get much use. For example, there are separate symbols for TradeMark - ™, Service Mark - ℠, and Prescriptions - ℞. Nestling among the "Letterlike Symbols" are two curious entries. Both of these are single characters: Telephone symbol - ℡ Numero Sign - № What's interesting is both .tel and .no are Top-Level-Domains (TLD) on the Domain Name System (DNS). So my contact site - https://edent.tel/ - can be written as - https://edent.℡/ And the Norwegian domain name registry NORID can be accessed at https://www.norid.№/ Copy and paste those links - they work in any browser! Is this limited to TLDs?

No!

This works ANYWHERE in a domain name. Copy and paste these examples: Script https://ℰ𝒳𝒜ℳ𝓟ℒℰ.𝒞𝓞ℳ/ Math Bold https://𝐞𝐱𝐚𝐦𝐩𝐥𝐞.𝐜𝐨𝐦/ Fraktur https://𝖊𝖝𝖆𝖒𝖕𝖑𝖊.𝖈𝖔𝖒/ Math bold italic https://𝒆𝒙𝒂𝒎𝒑𝒍𝒆.𝒄𝒐𝒎/ Math bold script https://𝓮𝔁𝓪𝓶𝓹𝓵𝓮.𝓬𝓸𝓶/ Double struck https://𝕖𝕩𝕒𝕞𝕡𝕝𝕖.𝕔𝕠𝕞/ Monospace https://𝚎𝚡𝚊𝚖𝚙𝚕𝚎.𝚌𝚘𝚖/ Super script https://ᵉˣᵃᵐᵖˡᵉ.ᶜᵒᵐ/ Sub script https://ₑₓₐₘₚₗₑ.cₒₘ/ NB not all characters supported Math sans bold https://𝗲𝘅𝗮𝗺𝗽𝗹𝗲.𝗰𝗼𝗺/ Math sans bold italic https://𝙚𝙭𝙖𝙢𝙥𝙡𝙚.𝙘𝙤𝙢/ Math sans italic https://𝘦𝘹𝘢𝘮𝘱𝘭𝘦.𝘤𝘰𝘮/ Math Squared https://🄴🅇🄰🄼🄿🄻🄴.🄲🄾🄼/ NB the dot must not be squared Circled https://ⓔⓧⓐⓜⓟⓛⓔ.ⓒⓞⓜ/ NB the dot must not be circled There are a whole bunch more miscellaneous characters you can use: How does this work?

Magic!

Which is to say, I think it is the browser doing the conversion. DNS Servers don't successfully reply to queries about .℡ domains. The browser sees the .℡ and then follows the IDNA2008 process listed in RFC5895 to normalise it: map characters to the "Simple_Lowercase_Mapping" property (the fourteenth column) in <http://www.unicode.org/Public/UNIDATA/UnicodeData.txt>, if any. The ℡ entry is: 2121;TELEPHONE SIGN;So;0;ON;<compat> 0054 0045 004C;;;;N;T E L SYMBOL;;;; U+0054 is T, U+0045 is E, U+004C is L. You can test this in Python using: python -c 'import sys;print sys.argv[1].decode("utf-8").encode("idna")' "℡" Does this work?

Yes!

I asked people on Twitter whether they could access my website using a .℡ - and it appeared to work on every modern browser and operating system. It even works on command line tools like wget and curl. It does fail in some circumstances: What are the limitations? Two main ones: Sites like Twitter and Facebook don't recognise it as a valid URl and refuse to auto link it. Some command line tools like dig and host don't understand it Copied Bash to 📋 Bashdig edent.℡ ; <<>> DiG 9.10.6 <<>> edent.℡ ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 55282 Is this useful? Obviously yes. This may be the most important discovery of the decade. You get cool looking URls and get to save a couple of characters on specific domains, at the minor expense of working inconsistently. It could also be used for evading URl filters. Every modern browser supports these "fancy" domain names - but most websites won't automatically link to them. So sharing on Facebook doesn't work. Where can it be used? Here are the single characters which can be normalised down to a valid TLD. They're mostly country codes, but there are a few interesting exceptions: ㏕ - US Military ℡ - .tel registry № - Norway ㍳ - Australia ㍷ - Dominica ㎀ - Panama ㎁ - Namibia ㎃ - Morocco ㎊ - French Polynesia ㎋ - Norfolk Island ㎏ - Kyrgyzstan ㎖ - Mali ㎙ - Federated States of Micronesia fi - Finland ㎜ - Myanmar ㎝ - Cameroon ㎞ & ㏎ - Comoros ㎰ - Palestine ㎳ - Montserrat ㎷ & ㎹ - Republic of Maldives. ㎺ - Palau ㎽ & ㎿ - Malawi ㏄ - Cocos (Keeling) Islands ㏅ - Democratic Republic of Congo ㏉ - Guyana ㏗ - Philippines ㏘ - Saint Pierre and Miquelon ㏚ - Puerto Rico ㏛ - Suriname ㏜ - El Salvador ℠ - San Marino ™ - Turkmenistan st & ſt - São Tomé and Príncipe ㎇ - Great Britain ( Obsolete) ß - South Sudan ( Not available) ㏌ - India and Indiana (subdomain of .us) Ⅵ & ⅵ - Virgin Islands and Virginia (subdomain of .us) fl - Florida (subdomain of .us) ㎚ - New Mexico (subdomain of .us) ㎵ - Nevada (subdomain of .us) ㍵ - As part of .ovh If you can find any more, please stick a comment in the box below. You can always reach this blog post at: https://🅂𝖍𝐤ₛᵖ𝒓.ⓜ𝕠𝒃𝓲/🆆🆃🅵/