What are the butterfly and medley rules I need to judge?

Question

Accepted Answer

Butterfly (World Aquatics Rule 8): Body on the breast from the first arm stroke after the start; no rolling onto the back except at the turn after the touch, and back on the breast on leaving the wall. Both arms brought forward together over the water and back together under the water. Leg movements simultaneous; legs need not be level but must not alternate. No breaststroke kick. Touch at each turn and the finish with both hands, separated and simultaneously (hands may not be stacked). After the start and each turn: any number of leg kicks but only one arm pull underwater, and the head must break the surface by the 15m mark. Swimmers may be fully submerged once the head has passed the 5m mark before the finish. Medley (Rule 9): Individual medley order: butterfly, backstroke, breaststroke, freestyle. Medley relay order: backstroke, breaststroke, butterfly, freestyle. In the freestyle section the swimmer must be on the breast (except when turning) and must return to the breast before any kick or stroke; backstroke, breaststroke or butterfly may not be swum as the freestyle leg. Each section must finish according to the rule for that stroke.