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