§ 15.19 Labelling requirements. This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:(1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. § 15.21 Information to user. Any Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. § 15.