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