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