Fork oils for competition and racing applications are generally suited to high performance motorcycle suspension systems operating at high revs and under high load. Types of use can include endurance, rally, short distance, Moto Cross, Enduro and trials. These fluids typically contain additives specifically designed to help reduce internal friction and minimise wear.
In order to provide a consistently smooth fork action with optimum damping qualities, it is advisable to follow the fork manufacturers specification. Normally you'll be able to find a viscosity or weight recommendation in your handbook.