https://letsencrypt.org/2016/10/21/introducing-idn-support
Introducing Internationalized Domain Name (IDN) Support - Let's Encrypt
Let’s Encrypt is pleased to introduce support for issuing certificates that contain Internationalized Domain Names (IDNs). This means that our users around the...
internationalized domain nameintroducingidnsupportlet
https://www.dynadot.com/help/question/what-is-IDN
What is an Internationalized Domain Name (IDN)? International Domain Names - Non-ASCII Character...
IDNs are domains with non-ASCII characters such as Chinese or Japanese. We support IDNs in a variety of languages and we also support IDN extensions!
internationalized domain namewhat isidnnamesnon