The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communication.
Its role is to manage the international radio-frequency spectrum and satellite orbit resources and to develop standards for radiocommunications systems with the objective of ensuring the effective use of the spectrum.
Source: http://en.wikipedia.org/wiki/ITU-R
ITU-Radio Recommendations (abstract)
BO Satellite delivery
BR Recording for production, archival and play-out; film for television
BS Broadcasting service (sound)
BT Broadcasting service (television)
F Fixed service
M Mobile, radiodetermination, amateur and related satellite services
P Radiowave propagation
RA RadioastronomyS Fixed-satellite service
SA Space applications and meteorology
SF Frequency sharing and coordination between fixed-satellite and fixed service systems
SM Spectrum management
SNG Satellite news gathering
TF Time signals and frequency standards emissions
V Vocabulary and related subjects