In the rich text editor:
@Drac0rex
In a comment:
[Drac0rex](https://chowlings.com/user/Drac0rex)
For Names and Avatars:
In the rich text editor:
%Drac0rex
In a comment:
[](https://chowlings.com/user/Drac0rex) [Drac0rex](https://chowlings.com/user/Drac0rex)