Functional Analysis of the MARC 21 Bibliographic and Holdings Formats

FRBR Display Tool
Version 2.0

Network Development and MARC Standards Office
Library of Congress



In 2001, the Network Development and MARC Standards Office released the publication, "Displays for Multiple Versions from MARC 21 and FRBR," which outlined how the FRBR (Functional Requirements for Bibliographic Records) model can be used to cluster bibliographic records retrieved via a search in more meaningful displays to assist users in selecting items from bibliographic collections. It contained several hierarchical display examples of bibliographic data using the FRBR model.

The FRBR Display Tool, based on the above analysis, is an XSLT program that transforms the bibliographic data found in MARC record retrieval files into meaningful displays by grouping the bibliographic data into the "Work," "Expression" and "Manifestation" FRBR entities. The matching and sorting specifications for the tool are outlined below.

The FRBR Display Tool sorts and arranges bibliographic record sets using the FRBR model. It then generates useful hierarchical displays of these record sets containing works that consist of multiple expressions and manifestations.

The tool is very flexible. Because the tool is written in XSLT, it is easy to augment based on an institution's individual needs. Likewise, the output may be augmented by simply changing the XSL stylesheet that controls display. No change in the XSLT program is needed.

The tool does not search bibliographic databases to create the record set on which it operates. A retrieved file (e.g., an OPAC search result) of MARC unit records must be created before using the tool.

In its current version, the FRBR Display Tool works best with record sets resulting from searches of name and title fields. Broader searches (for example, that include data matched in the 5XX note fields) promote less useful display results because the FRBR Display Tool does not display the field that caused the retrieval of a record unless that field was one already in the display elements.

One important factor that greatly impacts the usefulness of the FRBR Display Tool's results is the consistency of the bibliographic data. Data, for example, with typos or inconsistent headings, lessen the utility of the display because it prevents accurate and consistent collocation of data.

Suggested Usage

The following list indicates a few possible uses of the FRBR Display Tool. Please contact the Network Development and MARC Standards Office ( if you have used it for other purposes and would like to contribute to this list.

  1. Test FRBR concepts through experimentation with collocating and sorting files by segmenting MARC 21 records into the FRBR "Works," "Expressions," and "Manifestations" entities.
  2. Evaluate consistency and potential of local data for FRBR display.
  3. Experiment with an alternative front end display for library catalogs, based on FRBR concepts as a user option.

Tool Description

The FRBR Display Tool works with flat files of MARC unit records. It first generates a MARCXML document using the MARCXML Toolkit. It then transforms the MARCXML data into an XML encoded FRBR structure that uses selected MODS (Metadata Object Description Schema)) elements. Both XSLT 1.0 and portions of XSLT 2.0 standards are used to do most of the grouping of bibliographic items into the FRBR "Work, "Expression" and "Manifestation" entities. An HTML display is then generated from the FRBR XML document using an XSL stylesheet. The user of the FRBR Display Tool may alter the matching and sorting specifications in the XSLT components to accommodate characteristics of local data and change the XSL display stylesheet to reflect local display preferences.

The default HTML output used in the FRBR Display Tool links to the individual manifestations’ Library of Congress OPAC record using URLs that query the ILS. This linking mechanism may be changed so that the resulting display links to individual institutions’ online catalogs by modifying the FRBR XML-to-HTML stylesheet. Batch programs are packaged with the tool that provide a command line interface to it on a user’s computer. The only requirement is to have at least version 1.4 of the Java runtime environment installed.

How to Use

There is currently one way to use the FRBR Display Tool.

Transformation Program and XSL Stylesheet: You may download a zip file containing the following components: 1) FRBR Display Tool transformation stylesheets (written in XSLT); 2) the MARCXML Toolkit. (As noted above, the original matching and sorting specifications contained within the stylesheet components may be altered to match the needs of individual institutions.

Matching, Sorting and Display Specifications

The current version of the FRBR Display Tool is version 2.0.

The following display table outlines the matching, sorting and displaying processes used in generating the resulting FRBR display. They are given to assist analysis of results when using the tool and to help users determine where they may want to adjust the tool for their individual needs.

See the display example for further guidance on the display specifications used with the FRBR Display Tool.

Work Level
Define work level under: author and title


and Title:

Work Level
Define work level under: title only (do when no 100 (or) 110 (or) 111 field exists in record)

Expression Level

Manifestation Level

Display Example

Full Examples

Example 1: Title Search (Heart of Midlothian) (15 records)
Example 2: Author Search (Welty, Eudora, 1909-) (86 records)

Future Enhancements Under Consideration

The following enhancements are under consideration:

  1. Extension of matching, sorting and displaying to analytical headings from the 7XX fields.
  2. Display of the MARC 21 field that contains the retrieval data.
  3. Selective normalization of headings to circumvent cataloging rule changes found in large files.

MARCFRBR Electronic Discussion List

The MARCFRBR electronic discussion list has been set up to provide a means for discussion about experiments with and implementations of the FRBR Display Tool. This low volume list is focused on the tool so that the Library of Congress staff may share changes to the tool with those who are experimenting with it and implementors may share local changes and additions that they make to the Tool, as well as any problems they discover while using it.

To join the MARCFRBR discussion list, click here.

Comments and Suggestions

Please direct any comments and suggestions about the FRBR Display Tool to the Network Development and MARC Standards Office at: We would especially like to hear about the following from you:
  1. Was the FRBR Display Tool easy to install and initially use?
  2. How did you use the FRBR Display Tool? Did you experiment with it as is, or did you augment the program to meet your individual needs?
  3. What problems, if any, did you have while using the FRBR Display Tool?

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Library of Congress Help Desk ( 05/12/2009 )