scope:

This document defines the syntax as well as the semantics of the information to be included in the phone book for roaming applications. It comprises the information necessary to select the most appropriate ISP and to configure the host to get access to the network of the provider. The specification consists of a small set of required information elements and a variety of possible extensions. All data is specified in XML [5] (Extensible Markup Language) syntax leading to a concise XML DTD (Document Type Declaration) for the phone book.