Each semester, students are issued a demerit card with spaces for 40 demerits. Bart issues demerits to students for minor infractions and restores order to the school. A human's karmic acts result in merits and demerits. Each type of electrode has its merits and demerits. Guilt and its associated causes, merits, and demerits are common themes in psychology and psychiatry. Each shell material has its own merits and demerits. The merits and demerits a person has done may take a while to bear fruit. He was moderately successful at academics and received only a small number of disciplinary demerits. Tobacco use and gambling could lead to demerits, minor incarceration, or a loss of privileges. Accumulation of 3 demerits earns a detention. The others received demerits and other administrative sanctions. With mixed grades, his class rank was lowered by a fairly high number of demerits. Whistler bucked authority, spouted sarcastic comments, and racked up demerits. He earned a large number of demerits, especially in his final two years. Rules are enforced using a system of tours and demerits.