Principles of identification : European perspectives

Identifiers, like metadata, serve many different purposes. They are of course very useful for searching, since they may provide a unique access key to the identified resource. Selling electronic and even traditional books and journals is very dependent in identifiers; if a book purchase order or ILL request contains ISBN, it is much easier to deliver the correct product. Identifiers are also good for libraries’ housekeeping functions, such as deleting duplicate records from union catalogues. Identifiers are also essential for resolution services, systems which provide persistent linking between references and the resources themselves.