The List of Coast Stations and Special Service Stations (List IV) is a service publication prepared and issued, every two years, by the International Telecommunication Union (ITU), in accordance with provision No. 20.7 of the Radio Regulations (RR). Appendix 16 to the Radio Regulations prescribes which stations on board ships shall be provided with this List. This List is composed of a booklet (paper) containing the Preface and Reference tables and a CD-ROM (in pdf format) containing the complete data of coast and special service stations. The 2011 Edition of List IV effectively merges pertinent information from the previous List IV (List of Coast Stations) and List VI (List of Radiodetermination and Special Service Stations). As a consequence, previous editions of List IV and List VI are no longer available separately.