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