ATIS/ANSI O5.4.2009

The purpose of this document is to provide planning guidelines to NPA Relief Coordinators, affected parties and applicable regulatory authorities within affected NPAs within the North American Numbering Plan area. It lists the assumptions, constraints, and the planning principles used in NPA Code relief planning efforts. It also lists the steps of the NPA Code relief planning process and describes the alternative methods of providing NPA Code relief and their various attributes.