ITU-T RECOMMENDATIONS SERIES


 Series A	Organization of the work of the ITU-T
 Series B	Means of expression
 Series C	General telecommunication statistics
 Series D	General tariff principles
 Series E	Telephone network and ISDN
 Series F	Non-telephone telecommunication services
 Series G	Transmission systems and media
 Series H	Transmission of non-telephone signals
 Series I	Integrated services digital network
 Series J	Transmission of sound-programme and television signals
 Series K	Protection against interference
 Series L	Construction, installation and protection of cables and other elements of outside plant
 Series M	Maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits
 Series N	Maintenance: international sound-programme and television transmission circuits
 Series O	Specifications of measuring equipment
 Series P	Telephone transmission quality
 Series Q	Switching and signalling
 Series R	Telegraph transmission
 Series S	Telegraph services terminal equipment
 Series T	Terminal equipment and protocols for telematic services
 Series U	Telegraph switching
 Series V	Data communication over the telephone network
 Series X	Data networks and open system communication
 Series Z	Programming languages