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