How to add notes to individual callouts?

I use the callout tool for the most part assigning a number to issues in a markup that corresponds with a number in a final report. What I would like to do is add notes/comments embedded within the individual callouts but is unseen to the viewer. This way in my final report I still just have a clean number shown in my drawings. But if I want to look at what the actual issue was I can somehow access the hidden information.

Is there a way to do this in revu?