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