Option to hide rubrics from students / Or faculty notes on course content

Hi:) 
While creating rubrics for our teachers teaching our language courses I realized they are visible to students. I understand and agree with that logic - It's great for students to understand what to aim for, what the expectations are. 
but for me the power of the rubrics is being able to communicate with my teaching staff in specific moments specific things to pay attention to. 
For example, on our first assignment I would like our teachers to encourage the student regardless of their grade, and limit any feedback to only what is necessary. A comment like this is not relevant to the students and might even be discouraging. 
So I can tell my teachers, or have a file with instructions like this, but having it as rubrics is so useful because without looking for it or having to remember it they can have what they need when they need it. 
Could you add the option to hide rubrics from students? 
Or for example enable adding draft rubrics to assignments and have students not see the draft? 
Another solution would be the option to add 'faculty notes' in different locations along a course. These will be visible to the course faculty only (not to students).
Thank you!