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