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