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