In the rich text editor:
@Owletry
In a comment:
[Owletry](https://painted-relics.com/user/Owletry)
For Names and Avatars:
In the rich text editor:
%Owletry
In a comment:
[](https://painted-relics.com/user/Owletry) [Owletry](https://painted-relics.com/user/Owletry)