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