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