I'd like help with a problem I have posting marks. It goes like this:

1. I finish marking a class of student assignments. My grading policy is set to manual, so no-one can see their marks until posted.

2. I post their marks. Everyone receives a message saying the marks are now available for viewing.

3. A student submits an assignment a week late. I assess and mark the late assignment.

4. I want to post the late student's mark separately but it seems I have only the option of posting (all) marks again.

5. I post (all) marks again and everyone receives a message a second time, saying that marks have been posted.

How can I release the marks of a single late submission without sending a second unnecessary message to the class?

thanks in advance for any advice.