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