'revert to draft' button in files type assignments grading pages needs help button explaining it better.

currently in file type assignments , the 'revert to draft' button (also the 'no more submissions' button) is too vague about its functionality.

The button [ toggles between preventing and allowing changes to the assignment by the student ].
This is related to the 'send for marking' button that the student sees in the submission page to indicate that the assignment is ready for marking and that the student isn't going to be able to change any files unless the teacher reverts the submission to a draft.

We need a help button with a clear message to better describe what the functionality is to the user.