RULES IN BRIEF The "judoka" must bow to each other Clean, dry skin and short fingernails and toenails are obligatory Body odour is considered an offence Contestants must not make derogatory remarks or gestures to opponents. Being overly defensive can result in a penalty Pushing an opponent out of the contest area is forbidden, although a "judoka" can throw an opponent out of the area if he or she stays within it A contestant is considered to be out of the contest area if he or she places weight on any part of the body outside the area Avoiding an opponent is not allowed Submission is signalled by tapping twice or more on the mat with a hand or foot Punching or pressing on an opponents face is not allowed Bending back an opponent's fingers is not allowed If a bout is stopped because of injury, the opponent blamed for the injury loses the bout