Setting course visibility to ' restrict' from settings page to prevent students access without hiding it

To prevent enrolled students from accessing the course, one need to hide it.  After that, If any student looks for the course, they won't find it.  This is big concern in continuing education because the student (employee) could conclude that the course doesn't exist no more.

We suggest to have a third value ('restrict') for visibility in the Edit course settings page in the following way:

• hide 
• show
• restrict

With the last value, students  will still find the course in their searches,  but they couldn't access  nor enrol in it. In this way, they can know that the cours  is there but not available to students.   If needed, the teacher could  write an appropriate message (in course description) that will be displayed. 

Note that the course settings page is the only place where one can set this value.