@W0tnow it stands for Multi Specialty Recruitment assessment. Seems to be a strange way to recruit for specialities - testing potential Obstetricians on eyes !
They used to be able to sit it as many times as they like in January and October. But 10 days ago they told anyone who had passed (over 180 marks I think) that they can't take it again (no one seems sure when they will be able to have another go). Trouble is you need over 500 to even get an interview !
It's a real mess. I hope something is done asap. It's because Pearson say they don't have the capacity but it's almost now one go at staying as a doctor and then you're done. Bonkers.