This chapter gives an insight into the class of tracking problems in nonlinear systems for which the first-order derivative of the reference function does not exist. Using classical sliding mode control, only a restricted class of reference functions can be tracked. A solution to this problem by using fractional-order operators is proposed. The technique works provided the reference function satisfies the Hölder condition. Notably, its application to a switch-controlled RL circuit is demonstrated and some of the possible applications have been discussed.