In the rich text editor:
@Titi
In a comment:
[Titi](https://chowlings.com/user/Titi)
For Names and Avatars:
In the rich text editor:
%Titi
In a comment:
[![Titi's Avatar](https://chowlings.com/images/avatars/1349.png?v=1663019330)](https://chowlings.com/user/Titi) [Titi](https://chowlings.com/user/Titi)