The operation of a great number of integrated library systems with a reasonable number of bibliographic and duplicate records is necessary to the organisation of a shared cataloguing system. Large libraries tend to reach this level, while smaller public libraries require more and more records that can be downloaded and adopted. Various applications create opportunities for smaller units to join these networks. It is important from the point of view of the planning of co-operation that the TextLib system of the Metropolitan Ervin Szabó Library is widespread in Hungarian public libraries. Though academic libraries use different integrated systems, those having the same one can access one-another's catalogues. Elimination of the different implementations of library and computer standards, character sets is a significant prerequisite of co-operation.
The Corvina (formerly Voyager) integrated library system (which has the great advantage that Hungarian standards are applied in it as far as possible) are used by the university associations of Debrecen and Szeged respectively. There are about half a million bibliographic records in the catalogues of the two libraries, and the material acquired since the middle of the 1960s are covered by machine readable catalogues.
At present the system is used by 25 libraries, that is the conditions of shared cataloguing are given. Shared cataloguing efforts of Corvina libraries are called Vocal. The author presents the characteristics of the shared cataloguing system, work processes, the problems of bibliographic and subject cataloguing, and the anticipated steps of development.