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