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