In the rich text editor:
@raijin
In a comment:
[raijin](https://chowlings.com/user/raijin)
For Names and Avatars:
In the rich text editor:
%raijin
In a comment:
[![raijin's Avatar](https://chowlings.com/images/avatars/1596.png?v=1659500256)](https://chowlings.com/user/raijin) [raijin](https://chowlings.com/user/raijin)