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