arged individually. The director of the CCITT is assisted by a specialised secretariat, The technical work of the CCITT is undertaken by Study Groups made up of four departments. Department A plans the committees (SGs). There are fifteen Study Groups, differentiated by Roman and undertakes general affairs. Department B deals with the tele- letters, those for the study period 1988 - 1992, being shown in Table communication network and network components (Study Groups 22.1. There are also three special groups, as shown in Table 22.2. IV, X, XI, XII, XV, XVIII, GAS 7, GAS Department C deals with International standards organisations 22/9 telecommunication services and tariffs (Study Groups I, II, III, V, sembly. This means that standards could be ready within one year VI, VII, VIII, IX, XVII, GAS12). It is also responsible for liaison of starting work. with ISO. Department D is responsible for technical editing, for The CCITT has also adopted more of a co-ordination role between terminology and for the production of CCITT publications. the various national and regional standard making authorities. Key The CCITT works on a series of Plenary assemblies which meet amongst these are the USA T1 committees, the Japanese TTC and every four years. Traditionally a Plenary meeting sets the study the European ETSI. The ideas and work from these organisations, groups of the CCITT a series of 'questions' which are worked on along with that from R&D organisations, manufacturers, users and over the four year period. The outcome of this work are 'Recom- service providers, flows into and back out of the CCITT until they mendations' which are approved by the next Plenary and published are stable and accepted as standards. in volumes. Table 22.3 provides an overview of the content of the Blue Books The tasks of the Plenary Assembly are to: covering CCITT Recommendations. These Recommendations are designated by a letter which signifies which Study Group was Approve the work programme for the Study Groups, based on responsible for the r