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