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