In the rich text editor:
@Angelos
In a comment:
[Angelos](https://chowlings.com/user/Angelos)
For Names and Avatars:
In the rich text editor:
%Angelos
In a comment:
[![Angelos's Avatar](https://chowlings.com/images/avatars/1132.png?v=1644063254)](https://chowlings.com/user/Angelos) [Angelos](https://chowlings.com/user/Angelos)