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