Telematic, data transmission and teleconference services operations and quality of service : recommendations F.160 - F.353, F.600, F.601, F.710 - F.730 / International Telecommunication Union
Message handling and directory services operations and definition of service : recommendations F.400 - F.422, F.500 / International Telecommunication Union
International analogue carrier systems : recommendations G.211 - G.544 / International Telecommunication Union
Transmission media characteristics : recommendations G.601 - G.654 / International Telecommunication Union