In the rich text editor:
@Winter-blossom
In a comment:
[Winter-blossom](https://chowlings.com/user/Winter-blossom)
For Names and Avatars:
In the rich text editor:
%Winter-blossom
In a comment:
[![Winter-blossom's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/Winter-blossom) [Winter-blossom](https://chowlings.com/user/Winter-blossom)