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