In the rich text editor:
@SpaceCereal
In a comment:
[SpaceCereal](https://chowlings.com/user/SpaceCereal)
For Names and Avatars:
In the rich text editor:
%SpaceCereal
In a comment:
[](https://chowlings.com/user/SpaceCereal) [SpaceCereal](https://chowlings.com/user/SpaceCereal)