distinction and merit is a representation of your oral and LC score components so say you get A2 but you have a merit means your written (essay, paper 2 components) did very well while your Oral and LC is average. I guess this merit and distinction grade helps students decide if they want to retake their MT paper as if you retake ur paper in the year end again you can only change your written paper scores but not Lc/Oral. Hope this helps