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