What must a downhill rider wear?

• Helmet: "A full-face helmet must be worn properly both when racing and when training on the course." It must have a peak. Open-face helmets may not be worn.
• Jersey: long-sleeved, with sleeves down to the wrists, of a type designed for BMX racing or downhill.
• Not allowed: road cycling jerseys, skinsuits and one-piece suits joining jersey and trousers.
• At the waist: the jersey must fit closely or be tucked in before the start.
• Trousers: long and tear-resistant. Shorts are allowed if worn with protection covering the whole knee and shin.
• Recommended: rigid back, elbow, knee and shoulder protectors, neck protection, padding on shins and thighs and full-finger gloves.
• National rules: a national federation may make other protection compulsory at events on its territory.
• The rider's responsibility: the regulations note that there are no official technical standards for protective gear other than helmets, and leave the choice to the rider.
• Numbers: a handlebar number in training, and a back number as well in qualifying and the final.

The glossary has downhill and four cross.

The helmet rule answers the obvious risk of falling head first at speed on rock. The ban on skinsuits is about the contest as much as safety: it stops an arms race in aerodynamic clothing and keeps riders in kit that offers some protection in a slide.