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