In the rich text editor:
@sharkivore
In a comment:
[sharkivore](https://www.whistlercrest.com/user/sharkivore)
For Names and Avatars:
In the rich text editor:
%sharkivore
In a comment:
[](https://www.whistlercrest.com/user/sharkivore) [sharkivore](https://www.whistlercrest.com/user/sharkivore)