ABSTRACT
Digital information faces various threats from unstable media and technological obsolescence. In the library domain, the way in which digital information is created, published and distributed makes it more difficult for libraries to preserve material. Preservation management for traditional media is fairly well developed, with management tools and techniques, standards, guidelines and benchmarks to help in policy development and implementation of preservation programmes. Publishers can make the same underlying content available in a variety of digital versions and formats using various dissemination channels. The ephemeral nature of online information has implications for digital preservation. Online resources are updated, added to, deleted and moved, often without warning. Legal deposit libraries face some special problems in preserving digital information. Bibliographic control is well developed in the print environment, less well developed for non-print formats and, it seems, virtually non-existent for digital publications.
