The point-and-click idiom of World Wide Web access has made Internet browsing as easy as tapping on the door with your index finger, but every net surfer soon learns that, too often, the summons remains unanswered. The now-familiar Uniform Resource Locator (URL) can change at the whim of hardware reconfiguration, file system reorganization, or changes in organizational structure, leaving users stranded in 404 limbo... Document Not Found. The unpredictable mobility of Internet resources is an inconvenience at best. For librarians, it is a serious problem which compromises their service to patrons and imposes an unacceptably large burden on catalog maintenance.The general solution to this problem is the development of Uniform Resource Names, or URNs. The process of defining URNs has been underway in the Internet Engineering Task Force (IETF) for some time. OCLC is an active participant and supporter of this process.The persistence requirement of URN schemes is not a technological issue so much as an outcome of the social structures that evolve to meet a common community need. OCLC's origin is deeply rooted in precisely this shared commitment to providing reliable, long-term access to information. Standardization is necessarily slow and deliberate. Putting all the pieces in place will require consensus in the IETF, developments in the community of Web browser implementors, and deployment of new code by the community of network system managers who administer the Domain Name System (DNS) for the Internet. The concerns and problems of the library community may not be fully appreciated or adequately addressed by these groups in a timely manner. Libraries can and should provide leadership in the solution of these problems. To aid in the development and acceptance of URN technology, OCLC has deployed a naming and resolution service for general Internet resources. The names, which can be thought of as Persistent URLs (PURLs), can be used both in documents and in cataloging systems. PURLs increase the probability of correct resolution and thereby reduce the burden and expense of catalog maintenance.
This article is an updated version of PURLs to improve access to Internet by Stuart L. Weibel and Erik Jul from the 1995 November/December issue of the OCLC Newsletter, page 19.