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:

Christoph Päper 🇪🇺

@Cr1ss0v

Replying to @lambdalynx@lambdalynx @edent Wait, so one can use any of
㍳ ㏃ ㏇(!) ㏈ ffffifflfifl ㎇㎓㎬㏉ ㏋㍱㎐ ㎄㎅㎑㏍㏎㎸㎾ ㎃㎆㎒㎫㎹㎷㎿㎽ ㎁㎋№㎵㎻ ㍵ ㎀㎩㎊㏗㏙㏚㎴㎺ ₨ ℠ßst㏜ ℡㎔™ ㏝
ÅℬℂℭℰℱℐℑKℒℳℕℙℚℛℜℝℤℨ and more to leet-code URLs?
@urlstandard

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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.

Terence Eden is on Mastodon

@edent

Hey gang! I have a little experiment for you 🙂

Does this URL resolve in your browser?
https://edent.℡/
(That's https:// edent. ℡ /)

If it does or doesn't, could you let me know which browser and operating system?

THANKS!

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It even works on command line tools like wget and curl.

Mike

@6byNine

Replying to @edent@edent Things used to retrieve web pages rather than web browsers
curl 7.59, Linux - Yes
wget 1.19, Linux - Yes

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It does fail in some circumstances:

Ricardo Sueiras (@094459@hachyderm.io)

@094459

Replying to @edent@edent Yes, Chrome/Safari/Firefox running on Mac. The TEL however changed from superscript to normal text. If I copied/pasted into Word and then into the browser, the superscript is preserved and it no longer resolves (takes you to the google page with this page being the first hit)

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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

 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/🆆🆃🅵/

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