Radio frequency systems and equipment not included in Regulation (EU) 2021/821, components and accessories, specially designed or modified to develop any of the following functions: a. Take control and command of UAVs. b. Deliberately and selectively interfere with, deny, inhibit, degrade or deceive radio frequency signals for the control and command of unmanned aircraft. c. Use the specific features of the radio frequency protocol used by drones to interfere with their operation.