In the rich text editor:
@MysticEyes
In a comment:
[MysticEyes](https://chowlings.com/user/MysticEyes)
For Names and Avatars:
In the rich text editor:
%MysticEyes
In a comment:
[](https://chowlings.com/user/MysticEyes) [MysticEyes](https://chowlings.com/user/MysticEyes)