Registering g.net or a.com hasn't been possible since 1993, when the Internet Assigned Numbers Authority banned new registrations of single-letter domains. So how did the art duo JODI get their 2016 project to live on domains like ᠐.com?
The answer is that JODI, long exploiters of contradictions and loopholes in the mechanics of the web, picked symbols from beyond the Latin script, registering these domains using Punycode.
Punycode is an ASCII transcoding of Unicode meant to represent Internationalized Domain Names (IDNs). It allows domains to include international characters, but not in a way that could be misleading, such as creating "microsoft.com" with the lower-case o from another alphabet; those special symbols are expanded into a sequence beginning with xn--.
The ᠐ in ᠐.com is not a zero in Roman characters, but the Mongolian Numeral Zero, Unicode character 6160; depending on the font used, it can be visually identical to 0. Since the ASCII representation (in this case, xn--m6e.com) is what actually gets registered, JODI were able to work around the single-letter restriction.
This entry originally appeared at esoteric.codes/blog/jodis-idn, and may be a summary or abridged version.