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