In the rich text editor:
@LazyUser
In a comment:
[LazyUser](https://chowlings.com/user/LazyUser)
For Names and Avatars:
In the rich text editor:
%LazyUser
In a comment:
[![LazyUser's Avatar](https://chowlings.com/images/avatars/2644.png?v=1691783563)](https://chowlings.com/user/LazyUser) [LazyUser](https://chowlings.com/user/LazyUser)