In the rich text editor:
@sansnom8086
In a comment:
[sansnom8086](https://chowlings.com/user/sansnom8086)
For Names and Avatars:
In the rich text editor:
%sansnom8086
In a comment:
[![sansnom8086's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/sansnom8086) [sansnom8086](https://chowlings.com/user/sansnom8086)