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