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