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