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