Security consideration: math symbols in an exotic IP address format in a phishing mail

[Stephane Bortzmeyer]

On Sun, May 17, 2020 at 01:43:17AM +0200,
 Marius Spix via Unicode <unicode at unicode.org> wrote 
 a message of 15 lines which said:

> This worked for both Firefox and Chrome.

Also in a terminal with ping, so I suspect this is handled by lower
name resolution libraries.