the iaru rules specify that the choice of clothing is an individual decision of the competitor, unless the meet director specifies otherwise. although comfortable outdoor clothing is all that is required for participation, specialty clothing developed for the sport of orienteering is also worn by ardf competitors. nylon pants, shirts, or suits, gaiters or padded socks for lower leg protection, and specialty shoes for cross-country running through wooded terrain are popular choices. some competitors may choose to carry food or water on course, and wear a small waist pack or hydration pack for this purpose. at large international or national events, competitors may be required by the meet director to wear identifying numbers pinned to their clothing, and many wear team uniforms in their national colors.