This user's manual expands on the topics introduced in ARP5413, Certification of Aircraft Electrical/ Electronic Systems for the Indirect Effects of Lightning. Guidelines are provided which explain the approaches to compliance with the US Federal Aviation Regulations (FAR) and the European Joint Airworthiness Regulations (JAR). Discussions are applicable to all categories of airplanes and rotorcraft. This material as well as the Aerospace Recommended Practices (ARPs) it supports are not intended to provide mandatory approaches to compliance. In many cases, the path to compliance may use one or more of several methods. Applicants for Federal Aviation Administration (FAA) or Joint Aviation Authority (JAA) approval may elect to demonstrate compliance through alternative methods found acceptable by the FAA/JAA.