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