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