In the rich text editor:
@venus
In a comment:
[venus](https://chowlings.com/user/venus)
For Names and Avatars:
In the rich text editor:
%venus
In a comment:
[![venus's Avatar](https://chowlings.com/images/avatars/1914.png?v=1686515541)](https://chowlings.com/user/venus) [venus](https://chowlings.com/user/venus)