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