UDC52 is the class for astronomy of the Universal Decimal Classification. Revision of UDC52 was undertaken by G. Wilkins in the 1990s for the British Standards Institute (BSI) and with the approval of IAU Commission 5; however, this project is not in progress at present. In Russia, Ukraine and many other countries the UDC is an obligatory essential element of information in natural and engineering sciences due to the high activity of VINITI (All-Russian Institute of Scientific and Technical Information). At present the VINITI is publishing the fourth complete edition of UDC schedules in 10 volumes. Apparently in the near future, information about the state of the class UDC52, Astronomy, will be presented on the internet.

The Astronomy Thesaurus Project with the Multi-Lingual Supplement was realized by R. M. and R. R. Shobbrook in cooperation with librarians of different countries on the instructions of the IAU Commission 5. This list of terms with a definite hierarchy and relationships has demonstrated its usability for the building and development of the NASA ADS retrieval service.

We have finished the translation of the Astronomy Thesaurus into Russian, and are preparing the Ukrainian version as an extension of the Multi-Lingual Supplement in the development of the Russian VO.

We consider that establishing a special active Committee under Commission 5 for the updating process of the Astronomy Thesaurus and UDC52 and introducing into operation the up-to-date versions would be opportune and effective steps for IVO progress.