In the rich text editor:
@concreted
In a comment:
[concreted](https://chowlings.com/user/concreted)
For Names and Avatars:
In the rich text editor:
%concreted
In a comment:
[![concreted's Avatar](https://chowlings.com/images/avatars/1091.png?v=1651276371)](https://chowlings.com/user/concreted) [concreted](https://chowlings.com/user/concreted)