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