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Discussion Paper No. 2008-DP05/1: Using RDA Relators


RDA instruction 6.2.0 gives general guidelines on the designation of roles in conjunction with entities discussed in Chapter 6 (June 2007 draft). Appendix I: Relationship Designators: Relationships between a resource and persons, families and corporate bodies associated with the resource is a list of controlled terms which was compiled from a variety of sources, including RDA itself, AACR2, the MARC Relator list, and some specialized lists (e.g. RBMS or ONIX controlled lists of role terms).  This controlled list of role terms is given in an appendix to RDA.  There are several principles and assumptions that influenced the draft list of roles, as expressed in a memorandum which accompanied the February 2008 draft of the list.  These are:

Appendix I: Relationship Designators is organized by FRBR entity and by the element sub-types in Chapter 6 (June 2007 draft).  That is, there is a section on designation of relationships for works, for expressions, for manifestations, and for items, and within each by the element sub-types.  Relators for works specify roles used with creators and other persons, families or corporate bodies associated with the work. Relators for expressions indicate roles used with contributors; relators for manifestations indicates roles used with manufacturers, publishers and distributors; and relators for items indicate those used with owners and other persons, families, or corporate bodies associated with an item.

The MARC Code List for Relators establishes codes with their associated terms to indicate relationships between a name (i.e. person, corporate body, or conference) and a resource in bibliographic records.  The codes/terms are used in $4 and $e respectively, in 1XX, 270, 6XX, 7XX fields as well as series fields in 4XX and 8XX in the MARC 21 bibliographic format.  Relator terms may be used in authority records in $e of 100 and 110 and $j of 111 when the authority record is for a name/title. The list includes code, term, definition, references, and in some cases gives further guidance.

Artist [art]
Use for a person (e.g., a painter) or organization who conceives, and perhaps also implements, an original graphic design or work of art, if specific codes (e.g., [egr], [etr]) are not desired. For book illustrators, prefer Illustrator [ill].
UF            Graphic technician

It also indicates limited hierarchical relationships between distinct terms on the list, as does the RDA relator list.  For example, in the above MARC excerpt egr (engraver), etr (etcher), and ill (illustrator) are narrower forms of art (artist).  In RDA, Librettist is considered a subtype of Author.  (Note that RDA does not call these “relator” terms, but “Relators” (as of the May 12, 2008 version).  For consistency with MARC terminology, “relators” will be used in this paper for MARC and for RDA references.)

Note that this paper covers only the RDA relators in Appendix I (i.e. relationships between a resource and persons, families, or corporate bodies associated with a resource) and not those relators that define relationships between different resources (Appendix J and K).  The latter will be the topic of a later paper, since the RDA draft has not yet been made available. 


2.1. Comparison of the MARC Relator and RDA relationship designator lists

There is a significant degree of commonality between the MARC and the RDA relator lists, partly because the RDA list was developed with reference to the MARC list. Out of the total of 108 relators in RDA (May 12, 2008 draft), 65 are in the MARC Relator List with equivalent definitions, i.e. about 60% (MARC contains approximately 160 relator codes).  The definitions are often semantically the same.  Other relators found on the MARC list may be more or less granular than those on the RDA list.  Further analysis might find that additional relators in the RDA list are equivalent to others in the MARC list that use different terminology.

2.2. Using MARC Relator terms/codes for RDA relationship designations

Since many of the MARC Relator terms/codes have equivalents in the RDA Relator list, in many cases the MARC relator term/code could be used in the appropriate MARC subfield. In addition, the Library of Congress could consider adding the additional RDA role terms that are not currently on the MARC relator list, assigning them codes. Since the MARC list is intended to be a neutral list in terms that can be used by any cataloging rules and intended to serve a wide community of users, making these additional roles available on the MARC list might be a desirable option. Because of the desire to remain neutral, the MARC list would not limit the application of specific relationships to specific FRBR entity levels, as does RDA, but that is logically a cataloging rule stipulation.

2.3. Designation of authority list used for relator subfields

In subfield $4 in the MARC 21 formats, the use of the MARC Relator list is assumed as the source of the code.  The subfield $e does not make any assumptions about source.  There is not a mechanism currently to specify the source of a controlled vocabulary used in $e.  Many MARC fields contain a subfield $2 (Source) to indicate the source of the data (i.e. the authority for the content in the field), but generally, the data in subfield $2 is applicable to the entire field or the $a subfield of the field, rather than a particular subfield.  Exceptions have been 043 and 044 where the $2 source applies to the $b subfield, and 366 (Trade Price) where it applies to the $c subfield. If the RDA terms are added to the MARC list, addition of a subfield for source might not be necessary.

One option is to take out the reference in the format to the MARC relator list and allow for terms from either list.  The source of the list could be inferred by whatever mechanism is used to indicate that the record uses RDA rules (presumably field 040$e). Another option is to allow the relator term to be self-identifying, either by putting the source parenthetically before the data in the $e subfield or by using a URI for the term, which would implicitly show the source because it would be part of the URI. 

2.4. Developments in the MARC Relator list

The Library of Congress’ Network Development and MARC Standards Office has been exploring expressing all of its MARC code lists using the Simple Knowledge Organization System (SKOS) and making them available in that format in addition to the current XML.  SKOS is a specification that provides a semantic web friendly way to represent knowledge organization systems, such as thesauri or other controlled lists.  SKOS allows for expressing relationships between terms in the particular list, and the MARC relator list could be enhanced to indicate broader and narrower terms, allowing further consistency with the RDA list, which specifies role sub-types.  Consideration could also be given to indicating in the MARC list (using SKOS techniques) the relationship between the role term and its application to work, expression, manifestation or item level. Expressing the MARC list in SKOS requires establishing URIs for each entity (i.e. relator term/code) on the list.



In order to accommodate the RDA relator list, there are a few changes that may need to be made to the MARC 21 formats.  Changes to the MARC relator list do not require MARBI proposals, but there is a mechanism to apply directly to LC for new or revised relator terms/codes.

3.1. Definition of $4 in the MARC 21 Authority Format

Since RDA specifies relators to be used for the relationship between a person, family or corporate body to works and expressions, there may be a need to define subfields for relators where they are not already in the format. The authority format does not include $4, but does include $e (or another subfield as indicated) in the following:
X00, X10, X11 ($j).

However, it is not clear that relator terms/codes are needed in an authority record. It is possible that if authority records are used for works and expressions, they may be used to relate the role of the creator, etc. to the title. In addition, whether or not subfield $4 for relator code in the authority format is needed depends upon which option is chosen for recording the URI and whether the RDA terms are included in the existing MARC relator list and thus are assigned codes. Currently, the RDA list only includes terms in English.

3.2. Allowing for URIs for relator data

Since RDA will identify all terms in its role list with unique URIs, there may be a need to accommodate this data in MARC. It is proposed that URIs be encoded in subfield $4.


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