There are two plausible answers to that question
Which do you think makes most sense?
I think it should be mod/quiz:grade. Indeed I just confidently told one of my colleagues that is how it works, and we tried it, and found that I was wrong.
At the moment:
- If you have both capabilities, then everything works fine. You can access all the three quiz reports Grade, Responses and Manual grading.
- If you have mod/quiz:viewreports, but not mod/quiz:grade, the you see Grade, Responses. You can see the Manual grading link in the Navigation, but when you click it you get a fatal error. (Oops!)
- If you have mod/quiz:grade, but not mod/quiz:viewreports then you don't see any of the three report links in the navigation.
- If you have neither mod/quiz:grade, nor mod/quiz:viewreports then you don't see any of the three report links in the navigation.
(In case you are wondering, there is a separate capability 'quiz/statistics:view' for accessing the statistics report.)
So, I think the way it should work is
- mod/quiz:viewreports controls access to the Grade and Responses reports.
- mod/quiz:grade controls access to the Manual grading report.
In addition, I think the current behaviour should be considered a bug, and so we should fix this on stable branches. MDL-38557