In the rich text editor:
@kurusuen
In a comment:
[kurusuen](https://chowlings.com/user/kurusuen)
For Names and Avatars:
In the rich text editor:
%kurusuen
In a comment:
[![kurusuen's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/kurusuen) [kurusuen](https://chowlings.com/user/kurusuen)