"We believe that the community of information professionals who have organized and preserved the world's written treasures for thousands of years will not fail to continue to organize and preserve the world's digital treasures in the future, demonstrating their usual sensitivity and creativity, remembering the lessons history has taught them, and keeping in mind the interests of all their user communities, present and future, as they have always done". With these bold words, three experts in cataloguing tackle the topic of metadata; of "data about data". They examine the application of this concept to a variety of circumstances in which librarians may increasingly find themselves. Part One examines the characteristics of multiple metadata, the creation of metadata for both monographic and continuous electronic resources, and its integration into local catalogues and databases. Part Two explores metadata's effect on current developments in online reference, choice of metadata, archiving and digital preservation, and professional education, as well as possible future innovations. It is compulsory reading for library information specialists.