Electromagnetic interference (EMI) falls into two categories: unwanted current and interference energy generated by electromagnetic field emissions. The U.S. Federal Communications Commission (FCC) and similar German bodies, such as the German Verband Deutscher Elektrotechniker (VDE), have established regulations governing EMI. Engineers must filter out noise or eliminate ground loops. In the early stages of designing and developing cooling fans, using a capacitor or ferrite core can mitigate EMI issues.