In the rich text editor:
@Eclair
In a comment:
[Eclair](https://chowlings.com/user/Eclair)
For Names and Avatars:
In the rich text editor:
%Eclair
In a comment:
[![Eclair's Avatar](https://chowlings.com/images/avatars/559.jpg?v=1644063307)](https://chowlings.com/user/Eclair) [Eclair](https://chowlings.com/user/Eclair)