The initials NHI and ELT (for not handed in and elite athlete, respectively) both made sense to me. But CAN for chose not to attempt didn't make sense. So I clicked the link included in the sentence and discovered, as I had suspected, that CAN should be CNA. From "Edmonton teacher suspended for giving zero grades to students who deserve zeros" on The Georgia Straight online on June 1, 2012. Click the image to enlarge it.