What does this mean for my unit mark?

Although I have not yet been notified of my dissertation mark and been given a grade by the university due to the marking and assessment boycott, on blackboard under the dissertation section, I can see a grade which next to it says "Mark exempted for this user". What does this mean? And what might it mean for my grade/unit? I was quite unhappy and surprised when I saw this grade since I have been relatively consistent grade-wise, but this mark was particularly low.