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