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