Internal Program Version: libidn2  2.3.4

An implementation of the IDNA2008 specifications (RFCs 5890, 5891, 5892, 5893)

GNU Libidn is an implementation of the Stringprep, Punycode, and IDNA
specifications defined by the IETF Internationalized Domain Names (IDN)
working group. It is used to prepare internationalized strings (such as
domain name labels, usernames, and passwords) in order to increase the
likelihood that string input and string comparison work in ways that
make sense for typical users around the world. 

https://www.gnu.org/software/libidn/#libidn2