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