PORBASE – the National Bibliographic Database is the online Union Catalogue of the Portuguese Libraries. Established in 1986, PORBASE is managed by the Biblioteca Nacional de Portugal (BNP) and was made available to the public in May 1988. It is currently the major bibliographic database in the country gathering data from the BNP and over 170 other Portuguese libraries of many different sizes and types, from both public and private organizations.
PORBASE is open to the participation of any Portuguese library according to established Regulations, and it is aimed at optimizing existing resources and standardizing professional practices. Contributing to PORBASE demands the adoption of common principles and bibliographic standards, as generally definied in the PORBASE Chart of Principles.
Bibliographic format and cataloguing rules
The machine-readable cataloguing format used in PORBASE is the UNIMARC, both for bibliographic and authority data. The bibliographic description follows the Regras Portuguesas de Catalogação (Portuguese Cataloguing Rules) which implement the ISBD – International Standard Bibliographic Description and are based on the AACR2 – Anglo-American Cataloguing Rules.
Subject retrieval standards
For subject access the common standards adopted is the UDC - Universal Decimal Classification. Because of the collective nature of the database, with records coming from múltiple sources using many different subject tools and policies, only the UDC, due to its coded nature, can overcome the heterogeneity of subject languages. While retrieval by subject descriptors and headings is possible in PORBASE, it should be noted that the alphabetical subject index is not a controlled one, in the sense that it does not guarantee coherence and exhaustiveness in retrieval. In the context of the Project CLIP, several subject lists were made available for subject indexing in the fields of Fine Arts, Agriculture, Health Sciences, Environment and Social Issues. These are recommended for contributing libraries that wish to include the subject indexing of their records within PORBASE.
