Question 13/III - Tariff principles for international public facsimile services (continuation of Question 14/III studied in 1985-1988) Study of possible amendments and additions to the D-Series Recommendations relating to charging and accounting in the Bureaufax and Telefax services and interworking activities between those two services; possible development of tariff principles for the Telefax 41 service and for the Telefax service in the ISDN environment. Reasons for the study In conjunction with Study Group I's operational studies relating to Telefax 4, Study Group III should consider: - charging principles; - arrangements relating to international accounting; - arrangements relating to refunds; taking into account existing Recommendations on Bureaufax and Telefax. Future studies on international public facsimile services should also include the following items: - interworking with other services, e.g. Teletex, Videotex, etc.; - mixed mode operations; - wideband and higher speed services; - transit services.