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DATE: Dec. 15, 2006

NAME: Use of field 520 for content advice statements

SOURCE: Revealweb Union Catalogue

SUMMARY: This paper discusses using field 520 (Summary, etc.) in the bibliographic format to carry advice statements about types of content in items, primarily but not solely, for visually impaired users.

KEYWORDS: Field 520 (BD), Content advice (BD), Content warning (BD)

RELATED: 2006-DP02 (January 2006)


12/15/2006 - Made available to the MARC community for discussion.

01/20/2007 - Results of the MARC Advisory Committee discussion - A slight majority favored using bibliographic field 520 for content advice statements rather than field 521, which is more of a value judgement. It also agreed to define subfield $c to identify the agency that supplied the advice. Subfield $c may contain an organization code or free text. Adding a new first indicator value signifying content advice information was also recommended.


Discussion Paper 2007-DP02: Use of field 520 for content advice statements


A recent initiative in the UK set out to provide a web-based union catalogue of materials available in accessible formats in the UK. Launched in 2003, the Revealweb Union Catalogue uses MARC 21 bibliographic and holdings formats. However, in order to provide the level of detail required for users, it proved necessary to display content advice statements in some bibliographic records.


In designing a union catalogue for visually impaired people, it has been necessary to bear in mind their specific user needs in terms of data held, data display and filtered searching. One practice used by agencies supplying audio versions of books is to indicate when there is a substantial amount of strong language, violence and/or sex scenes in a work. In situations where the user expects to be able to listen to a text without using headphones, and in a location where other people can also hear the text, users require guidance on content. If the content is inappropriate for the context, the user has the choice of waiting until they are alone before listening, or using headphones, or perhaps not requesting that item. The visually impaired user is usually choosing items from a tactile list, an audio list, or an accessible database. They cannot pick up the item and scan its contents to get this information. There is no intention to censor items, only to provide information; very few materials require this information and decisions to include such data and the rules to use in assigning it come from supplying agency reader services – cataloguers are not required to make an assessment.

Some discussion on email lists prior to the meeting indicated that content advice statements might also be of use in contexts outside the visual impairment sector. For example, MPAA (USA) and BBFC (UK) film classifications use age limits as their ratings classification, but this does not indicate the specific issue(s) that have resulted in the classification. Use of content advice information would enable the user to see that of two films with the same rating, film A contains scenes of violence, while film B contains both swear words and sex scenes, and subsequently make decisions on borrowing and the conditions in which they view the item in their home.

Note that Revealweb uses the bibliographic and holdings formats. A bibliographic format record is created for each standard print text used as a source of transcriptions. Holdings records are created for each accessible format using a particular print source text. The content advice statements are needed in the bibliographic record as they relate to the text content and are not specific to a single accessible format (audio cassettes, CDs, and DAISY files can all carry audio content). Other catalogues for accessible format materials (e.g. the Canadian National Institute for the Blind (CNIB) and the National Library Service for the Blind and Physically handicapped (NLS BPH) at the Library of Congress) create bibliographic records for individual accessible materials.

For example, the Canadian National Institute for the Blind (CNIB) includes content advice statements in field 520, placing these at the end of the summary statement itself.

The National Library Service for the Blind and Physically Handicapped (NLS/BPH) at the Library of Congress also includes this type of information on its records for the participants in their talking book and Braille programs. Currently the Service uses the MARC 21 format and the Library's Voyager system for their catalog. Previously in a local system there were codes for this information in the database. On conversion to Voyager, these codes were converted to stock phrases that are placed in repeating 521 (Target Audience Note) fields. A subfield $b is also included to indicate the organization that determined the information. The values are quite similar to those needed by the Revealweb Union Catalogue:

521 ## $aContains descriptions of sex.$bNLS/BPH
521 ## $aContains descriptions of violence.$bNLS/BPH
521 ## $aContains strong language.$bNLS/BPH

Where the conditions occur, the Service also includes as part of the field 520 (Summary, etc.) sentences that give the same information, often with an indication of degree, such as "Explicit descriptions of sex and strong language" or "Some strong language and some violence".

Revealweb considered using field 521 in early development of its bibliographic standard but decided that it was inappropriate. The content warnings relate objectively to the content (for example, this resource contains swear words) and only relate indirectly to audience. In some cases, knowledge of the content in question will be applied to certain audiences – an adult will choose not to broadcast this when children are present. In other cases, the information will enable the user to choose not to broadcast this when other people are present, regardless of their age, or alternatively will choose not to borrow the item at all.

Discussion Paper 2006-DP02 (Addition of coded value to 008 for content alerts in the MARC 21 bibliographic format) proposed adding a coded value to 008/32 in the bibliographic format to enable this information to be used as a search filter. Concern was expressed over re-using an obsolete 008 position and the meeting decided against making the proposed extension to 008 coding.

However, the principle of the need for this information in bibliographic records was accepted, and it was suggested that a new discussion paper be submitted for using a variable field to hold content advice statements.

Within Revealweb, this information is already held in field 520 (Summary, etc.). At present, Revealweb uses the first indicator position value 2 (Scope abstract). If the use of content advice statements is to be potentially used more widely, then it may be appropriate to designate a new first indicator value (value 4 = Content advice).

Discussion with other interested parties elicited some concern over how the content advice would be found using field 520, and the suggestion that it may require an explicit instruction that this information should be entered in a separate 520 field (Field 520 is already repeatable). A separate 520 for the content advice also supports the argument for establishing a new indicator; this could expedite machine use of the advice. Subfield $c has been suggested as a possible addition to indicate the agency giving the advice.

2.1 Values

The first indicator values that are currently used in the bibliographic records of the Revealweb Union Catalog are the standard MARC 21 values:

520 - Summary, etc.

First indicator: Display constant controller
# = Summary
0 = Subject
1 = Review
2 = Scope and content (used for Revealweb content warnings)
3 = Abstract
8 = No display constant required

It is suggested that value 4 be added to MARC 21 for content alert information.

It is also suggested that subfield $c (Source of information) be added to field 520. It would contain a code for the agency that supplied the advice. Examples are:

The introductory text to field 520 should be extended with a further paragraph specifying that content advice should be entered in a separate field. For example:

Content advice information should be entered in a separate field and not added on to the end of other summary, abstract or review information.

2.2 Examples

2.2.1 Audio book examples

520 4# $aContains violence$c[Revealweb organization code]
[A non-fiction work on the crimes of serial killers, with murders described in detail.]

520 4# $aContains swear words, sex scenes and violence$c[Revealweb organization code]
[For a work of fiction that includes a combination of strong language, violence and sex scenes. For example: The indiscretions of Isabelle / Penny Birch writing as Cruella, which includes descriptions of flagellation as well as lesbian sex scenes.]

2.2.2 Film examples from British Board of Film Classification (BBFC)

Treasure of Albion
521 ## $aU$2BBFC
520 4# $aContains mild violence and threat$c[Source]

Happy feet
521 ## $aU$2BBFC
520 4# $aContains some intense scenes of action and threat$c[Source]

521 ## $aPG$2BBFC
520 4# $aContains crude humour$c[Source]

521 ## $aPG$2BBFC
520 4# $aContains mild fantasy violence and scary moments$c[Source]

Smoking aces
521 ## $a18$2BBFC
520 4# $aContains strong bloody violence$c[Source]

Belle de jour
521 ## $a18 $2BBFC
520 4# $aContains strong sexual theme and fetish scenes$c[Source]

  1. Should the bibliographic format be extended to include specific provision for content alert information?
  2. If yes, should field 520 first indicator value 2 be redefined to include content advice statements or should a new indicator value 4 be defined?
  3. Whichever indicator value is chosen, should 520 be extended with a subfield for source (as per current NLS/BPH practice)?
  4. Should content alerts be entered in separate fields from other summary information held in field 520?

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