Occasionally (i.e., about 10-20 times in the last 1.5 years) I see players joining the server who appear to be using non-standard characters in their messages. I've been trying to identify the method those players are using, but I haven't managed to find any real lead.
They are answering questions rather quickly using this font, I have therefore eliminated the possibility of copy/pasting every character from a list.
About a year ago I was able to verify that everyone using these characters (over the course of multiple months) was sending messages with the same set of characters. Creating a custom keyboard layout with such Unicode characters shouldn't be too difficult, but I don't think it explains the fact that so many independent players use the same character set without any variation.
I have tried searching the Unicode tables to identify the symbols - especially the unusually long underscore - but I have been unable to find the exact characters.
It also appears to be toggleable - some of the players immediately returned to normal ASCII characters after being requested to stop it.
I am a member of a Spigot server, but this has (once) happened on an unmodified server as well.
Are there any known ways to reproduce this behavior?