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