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Registry of Digital Masters

New: Registry of Digital Masters Record Creation Guidelines.
Version 2.0. May 2007.


The DLF takes a growing interest in helping to define and facilitate the development of key "infrastructural services" that are required by digital libraries but beyond the capacity of any one of them to develop. This page introduces work being conducted by the DLF defining the need for and the requirements of a service that registers the existence of persistent digitally reformatted and born digital monograph and serial publications.

It also points to additional materials including a general case for the development of a registry, a functional requirement for the service as it pertains to digitally reformatted materials, a functional requirement for the service as it pertains to born digital materials, a report on a meeting that was convened by the DLF in April 2001 to launch discussion about a registry service, and a report of a meeting held with OCLC in November 2001 to discuss implementation of the a service.

Although the registry service is not intended to be exclusive (it records information about the large and valuable legacy of digitized and born digital monographs and serials) its existence provides an opportunity to identify and build consensus around minimum characteristics that might be expected generally of a faithful digital master. Accordingly, this document points to related work conducted by the DLF to define those minimum characteristics.


An increasing number of libraries and commercial entities are involved in converting existing paper-based monographs and serials to digital form. Unlike the special collections materials that have been the focus of digital conversion in many libraries, monographs and serials are commonly duplicated in many different institutions. This presents both an opportunity and a threat. The opportunity is for coordination between institutions, with the efforts of each contributing to a larger shared but distributed collection. The threat is that resources will be wasted in the repeated digitization of the same material. A key requirement to realizing the opportunity and avoiding the threat is a mechanism for sharing information in a coherent fashion between institutions about what has been digitized; that is, the creation of a registry of digitized materials. (It should be noted that a related effort is underway to define a registry for recording long-term responsibility for the storage and preservation of paper originals. Such a resource will allow an institution to decide whether to preserve the original source documents for which digital surrogates exist.)

The Registry provides a place for institutions that have created (or are otherwise responsible for) digitized versions of traditional printed monographs and serials to record:

  • what specific items have been (or are about to be) digitized;
  • where they can be accessed;
  • the specifications followed in digitization.

There are two specific types of use the Registry must support:

  • Staff engaged in digitizing efforts should be able to discover whether a specific item has already been digitized, and if so whether the digitization has been done at an adequate level such that another digital copy is not required.
  • In the spirit of many contemporary metadata efforts, the data contributed to the Registry should be available for large-scale extraction and reuse. One obvious type of reuse that can be envisioned is the ability of a library to extract catalog records for materials digitized elsewhere for inclusion in its own local catalog. Another would be the gathering of metadata about digital materials in a specific topical area for inclusion in a portal or subject catalog.

    Some of the benefits that may flow from the registry are documented in More Access at Less Cost. The Case for a Digital Registry.


    Initially the Registry was intended for information about faithful reproductions of monographs and serials originally published in paper format. ("Faithful reproductions" are copies intended to preserve the original appearance of published materials, and must include digital images of all pages in the original.) The scope of the initiative was later extended to include born digital monographs and serials.

    Where digitally reformatted materials are concerned, reproductions should be of meaningful bibliographic entities as traditionally described in library catalogs: entire volumes of a monograph, whole issues of journals (not single articles). The intent is to record only entities traditionally described in MARC bibliographic and holdings records. By recording materials in the Registry, institutions are signaling the intent to preserve and maintain the accessibility of the described materials over an extended timeframe (decades or centuries, not years). This implies that materials are digitized carefully, complying with established standards and best practices, and that they are stored in professionally managed systems. When registered, materials should already be digitized, or be in an active queue for digitization. A use copy of any material registered must be available on-line (either for free or through some normal business arrangement such as subscription or a charge-per-use basis) to the general public.

    The Registry is not exclusive. It is able to record information about the large and valuable legacy of digitally reformatted and born digital monographs and serials. It is also able to encourage data creators and data users to determine independently and for their own purposes, what constitutes a faithful reproduction. The existence and use of a Registry provides an opportunity to identify and build consensus around minimum characteristics that might be expected generally of digital monograph and serial content. Characteristics of digitally reformatted material are documented in the benchmark now endorsed by the DLF.


    To achieve the benefits that are documented here, the registry supports a number of specific uses. It has the ability to record certain kinds of data about registered objects (e.g. bibliographic and holdings data), make recorded information available to users in particular ways, and support appropriate data input and data maintenance. To assist in the development of a viable registry, minimum or base level functional requirements statements have been prepared - one for digitally reformatted monographs and serials and one for born digital monographs and serials. Both derive from an early functional requirements statement developed exclusively for digitally reformatted materials.

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