Figure skaters must wear authorized skates. Men are required to wear pants or trousers. Tights, trousers, or unitards are required for women. Athletes' performances must change from routine to routine. Skaters can use only their own blades. The rulebook goes on to state that unauthorized equipment may be confiscated by ISU officials and may result in a penalty. They may also choose not to perform if they feel like it may cause injury to themselves or another skater. In addition to this, all skaters must follow the rules listed in chapter III of the code of conduct. These rules include general behavior such as "conduct yourself with respect" and "don't act like a fool." There is also a section on discrimination based on physical characteristics, such as "Don't pick on people because of their weight or height." Violations of these rules may result in sanctions ranging from warnings to disqualification. Sanctions are used to encourage fair competition and preserve the integrity of the sport. Disqualifications are applied when a violation has prejudiced the outcome of an event. In other words, when a violation affects the scoring system or judge's decision, it may result in a disqualification.