The CCUC is a catalogue with over 3,400,000 bibliographic records that provides access to over 6,000,000 physical documents conserved in over 160 libraries. The growth of the CCUC is based on current or daily and retrospective cataloguing, which are performed directly through the catalogue, and the incorporation of collections from other libraries. Many institutions that are not members of the CBUC have incorporated their records in the CCUC and others are expected to do so in the future.
The CCUC can be consulted on the Internet and has links with the local catalogues. When users have located a document, they can surf to any of the centres that have it and consult both its location and its state. This mechanism of links provides constantly updated information on the state of the journals collections. The CCUC also has links with other electronic resources of the Digital Library of Catalonia.
The CCUC also has a quality control programme that is aimed at eliminating duplicated records and headings. In the area of the CCUC, cooperative cataloguing has made it possible to carry out a thorough unification of cataloguing standards such as the different levels of coding, the treatment of serial publications, cartographic material, electronic resources...
From the CCUC, the users of the libraries of the CBUC can request books and photocopies of serial publications on interlibrary loan.