In the rich text editor:
@Mew
In a comment:
[Mew](https://chowlings.com/user/Mew)
For Names and Avatars:
In the rich text editor:
%Mew
In a comment:
[![Mew's Avatar](https://chowlings.com/images/avatars/3.gif?v=1729549232)](https://chowlings.com/user/Mew) [Mew](https://chowlings.com/user/Mew)