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