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