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