Document categories

The International Telecommunication Union (ITU) publishes a vast range of documents categorized under different series, each dedicated to specific subjects in the field of telecommunications or information technology. Below are some key document series published by ITU.

Summary

The following is a summary table of all the ITU document categories.

Series	Description
A	Administrative issues and policies
B	Telegraphy
C	Radiocommunications (ITU-R)
D	Tariff and accounting principles including related telecommunication economic and policy issues
E	Overall network operation, telephone service, service operation and human factors
F	Non-telephone telecommunication services
G	Transmission systems and media, digital systems and networks
H	Audiovisual and multimedia systems
I	Integrated services digital network
J	Cable networks and transmission of television, sound program and other multimedia signals
K	Protection against interference
L	Construction, installation and protection of cables and other elements of outside plant
M	Telecommunication management, including TMN
N	Maintenance: international sound program and television transmission circuits
O	Specifications of measuring equipment
P	Telephone transmission quality, telephone installations, local line networks
Q	Switching and signaling
R	Telegraph transmission
S	Telegraph services terminal equipment
T	Terminals for telematic services
U	Telegraph switching
V	Data communication over the telephone network
X	Data networks and open system communications
Y	Global Information Infrastructure, Internet protocol aspects and Next-Generation Networks
Z	Languages and general software aspects for telecommunication systems

Details

A Series - ITU Council Documents

The A series comprises documents related to administrative issues and policies, including documents from the ITU Council and other high-level meetings.

B Series - Telegraphy

This series covers the guidelines, standards and technical requirements related to telegraphy.

C Series - Radiocommunications (ITU-R)

The C Series includes decisions, resolutions and other formal results from World and Regional Radiocommunication Conferences.

D Series - Tariff and accounting principles including related telecommunication economic and policy issues

The D series concerns tariff and accounting issues, including costing methodologies, economic, and policy-related matters across telecommunication services.

E Series - Overall network operation, telephone service, service operation and human factors

The E series provides recommendations for telephone service, network operation, service operations, and human factors.

F Series - Non-telephone telecommunication services

The F series covers various non-telephone telecommunication services like facsimile, data communication, telegraph services, and teletex services.

G Series - Transmission systems and media, digital systems and networks

The G series focuses on standards for digital networks and transmission systems and media. This includes systems and networks, line transmission of traditional and digital signals, and optical technology for networks.

H Series - Audiovisual and multimedia systems

The H series covers standards for designing and implementing audiovisual and multimedia systems.

I Series - Integrated services digital network

The I series pertains to the integrated services digital network (ISDN) and its related aspects.

J Series - Cable networks and transmission of television, sound programme and other multimedia signals

The J series provides standards for cable networks and transmission of television, sound programs, and other multimedia signals.

K Series - Protection against interference

The K series focuses on protection from interference, which includes protection from environmental factors that can inhibit communication signals.

L Series - Construction, installation and protection of cables and other elements of outside plant

The L series provides guidelines on the construction, installation, and protection of cables and other outside plant elements.

M Series - Telecommunication management, including TMN

The M series offers guidelines for telecommunication management, including the Telecommunication Management Network (TMN).

N Series - Maintenance: international sound program and television transmission circuits

The N series focuses on the maintenance of international sound programming and television transmission circuits.

O Series - Specifications of measuring equipment

The O series offers specifications for measuring equipment used in telecommunications.

P Series - Telephone transmission quality, telephone installations, local line networks

The P series covers various aspects of telephone transmission quality, telephone installations, and local line networks.

Q Series - Switching and signalling

The Q series covers standards related to switching and signaling in telecommunication systems.

R Series - Telegraph transmission

The R series covers standards for telegraph transmission.

S Series - Telegraph services terminal equipment

The S series offers standards for terminal equipment used in telegraph services.

T Series - Terminals for telematic services

The T series provides standards for the terminals used for telematic services.

U Series - Telegraph switching

The U series covers standards related to telegraph switching.

V Series - Data communication over the telephone network

The V series pertains to standards for data communication over the telephone network.

X Series - Data networks and open system communications

The X series provides standards and protocols for data networks and open systems communication.

Y Series - Global Information Infrastructure, Internet protocol aspects and Next-Generation Networks

The Y series covers standards for global information infrastructure, internet protocol aspects, and next-generation networks.

Z Series - Languages and general software aspects for telecommunication systems

The Z series provides standards for programming languages and general software aspects for telecommunication systems.

These recommendations and guidelines issued by the ITU play a vital role in the development and smooth functioning of global telecommunications and IT networks.