PROPOSAL NO.: 2002-01

DATE: December 18, 2001

NAME: Definition of Subfield $u (URI) in Field 670 (Source Data Found) in the MARC 21 Authority Format

SOURCE: Library of Congress

SUMMARY: This paper proposes the definition of a subfield $u in field 670 to provide a link to information accessed electronically that provides a reference source for an authority record.

KEYWORDS: Field 670 (AD); Source data found (AD); Subfield $u, in field 670 (AD); Uniform Resource Identifier (AD)

RELATED: 98-13 (June 1998)


12/18/01 - Made available to the MARC 21 community for discussion.

01/21/02 - Results of the MARC Advisory Committee discussion - Approved. There was some discussion regarding the need to define subfield $u in field 670 (as requested by LC for use by NACO participants) since field 856 could be used to provide such a link. However, since this was considered a policy issue, participants considered it desirable and appropriate to allow for a URI in field 670.

03/20/02 - Results of LC/NLC review - Approved.

PROPOSAL NO. 2002-01: Definition of Subfield $u (URI) in Field 670


Proposal No. 98-13 proposed extending the 856 field to the Authority format as a means of improving access to information about the entity covered by the authority record. The discussion at the MARC Advisory Committee meeting in June 1998 revealed the need for some clarification about under what circumstances the field would be used in authority records, since there could be controversy about when it was appropriate, given the uneven quality of information on the Web. It was agreed that policy making bodies such as NACO would need to issue guidelines as to the field's use. In the meantime, it was felt that LC should be conservative in showing examples in the format so that only non-controversial uses be given (e.g. a corporate body's Web site).

Recently the Library of Congress issued a statement clarifying that it had decided not to use field 856 in authority records created at LC and would not accept it in those contributed through the Program for Cooperative Cataloging's NACO project. Instead, LC suggested the addition of a new subfield $u in field 670 for linking to a Web resource that gives information about the heading in the record.


Field 670 (Source Data Found) contains a citation for a consulted source in which information is found about the 1XX heading in an authority record. It is defined as follows:

$a - Source citation (NR)
$b - Information found (NR)
$6 - Linkage (NR)
$8 - Field link and sequence number (R)

Subfield $a contains a citation for a work or a description of a source that provided information about the heading. Subfield $b contains a location within the resource where the information is found (if applicable) and a parenthetical statement of the information found in the source. If subfield $u were defined, it could contain an electronic link to the citation.

Because of the potential ambiguity between the data that would be recorded in a field 856 in an authority record and its relationship to the heading in the 1XX field, LC felt that recording the URI in a field 670 $u would provide more clarity. It would also reduce the redundancy of data in the authority record, since it would be necessary according to guidelines to add information in a subfield $b of the 670 field even if field 856 were used. In situations where subfield $u is present, subfield $b would still contain a summary of the data found in the source. Subfield $u would provide a link to the URI for access to additional information.

Although field 670 may not be displayed in public access catalogs, LC felt that it was not necessary to add subfield $u to other authority fields. For instance, field 680 (Public General Note) contains a public note that would likely be displayed, but this field is not generally used for name authority records. In addition, LC felt that a subfield $u in field 680 would not be useful for subject authority records. Since field 670 is a citation, it seems to be the most appropriate field in which to include a subfield $u.

Note that the definition of subfield $u in field 670 is not intended to be a replacement for its use in field 856, which is already defined in the MARC 21 Authority Format. For those institutions that wish to use 856 perhaps for public access to the information, it would still be available.

The record creator would need to use judgment in determining which URI to record, since some information may be in subsequent pages linked to the main resource. A consideration is that the main page may be more persistent and its URI should be recorded even if some of the information cited may be from subsequent pages.


These examples do not include all fields in the authority records.

010 ## n 79063767
100 1# $aKing, Stephen, $d1947-
400 1# $aKing, Stiven, $d1947-
500 1# $aBachman, Richard
670 ## $aHis Carrie, 1974.
670 ## $aWashington post, 4/9/85 $b (Stephen King has written 5 novels using the pseudonym Richard Bachman)
670 ## $a The official Stephen King web presence, viewed Oct. 26, 2001: $b The man (Stephen Edwin King; b. Portland, Maine, 1947) $u

010 ## $anr 95032432
110 2# $aBritish Oceanographic Data Centre
410 2# $aBODC
510 2# $wa$aBritish Oceanographic Data Service
670 ## $aGEBCO digital atlas, c1994: $bdisc label (British Oceanographic Data Centre, Bidston Observatory, Birkenhead, Merseyside; BODC)
670 ## $aBritish Oceanographic Data Centre, viewed Oct. 17, 2001: $bHistorical overview (BODC, est. Apr. 1989; developed from the British Oceanographic Data Service (BODS)) $u

010 ## $an 80015640
110 2# $aCatholic Church. $bNational Conference of Catholic Bishops
410 2# $aNational Conference of Catholic Bishops
670 ## $aIts Hirtenbrief der Bischofskonferenz der Vereinigten Staaten von Amerika über den marxistischen Kommunismus, 1980: $bt.p. (Bischofskonferenz der Vereinigten Staaten von Amerika)
670 ## $aUnited States Conference of Catholic Bishops, viewed Sept. 17, 2001: $bWho we are (On July 1, 2001, the NCCB [National Conference of Catholic Bishops] and the USCC [United States Catholic Conference] were combined to form the United States Conference of Catholic Bishops (USCCB). The USCCB continues all the work formerly done by the NCCB and the USCC with the same staff. The bishops themselves form approximately 50 commitees, each with its own particular responsibility) $u
    [The subfield $u is for the main page for the name cited in 670$a, although the information is from a subsequent page linked to the main page as "Who we are".]


In field 670 (Source Data Found) in the MARC 21 Authority Format:

Define subfield $u as follows:

u - Uniform Resource Identifier (R)
Subfield u contains the Uniform Resource Identifier (URI), for example a URL or URN, which provides electronic access data in a standard syntax. This data can be used for automated access to an electronic item using one of the Internet protocols.

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