There are several JIRA that have in common the desirability of providing functionality so that instructor role can add freeform metadata about a given assignment. The metadata display in some cases is triggered by a combination of user actions, time, roles.
SAK-4384 "Model" solution feature for assignments
SAK-7653 Add 'model answer' in assignments to be released once submissions are graded/returned
SAK-5803 Hints / Documentation Needed for Submitting Assignments
SAK-10211 Ability to add notes for instructors to assignments
Use cases (from the JIRA)
Use Case 1 Instructor provides model answers that display to student at a given moment
Use Case 2 Instructor provides notes to other instructors and graders to normalize assessment grading, provide grading rubrics, etc. In any case - this is information that is shared between instructor role members.
Use Case 3 Instructor keeps notes on assignment while grading it - assume this is on the assignment proper, not on individual student submissions
See attachment for a bit more detail.
See attached zipped velocity templates for some display guidelines.