The following fields on accessiblty was added to MARC21 in November, 2018.

• 341 – Accessibility Content
• 532 – Accessibility Note

In order for the above fields to be actually used among libraries, RDA (Resource Description and Access) ‘s support is required. This is because RDA is the major standard for cataloging for libraries.

Current status of RDA

RDA does not support 341and 532 fields both of which were added in 2018 yet because RDA”s offical latest version is 2017 version. With regards ot accessiblity, RDA 2017 version provides accessibility content as content element of Expression as follows.This element corresponds 500 fields (General Note) and 546 fields (Language Note) of MARC21 as of now.

7.14 Accessibility Content
7.14.1　Basic Instructions on Recording Accessibility Content
7.14.1.1　Scope
accessibility content: An indication of content that provides alternative sensory modes to perceive the primary content of an expression.
Accessibility content includes accessible labels, audio description, captioning, image description, sign language, and subtitles. Accessibility content does not include subtitles in a language different from the spoken content.
7.14.1.2　Sources of Information
Take information on an accessibility content from any source.
7.14.1.3　Recording Accessibility Content
Record information about an accessibility content if the information is evident from the manifestation or is readily available from another source.
EXAMPLE
Closed captioning in German
Includes subtitles
Open signed in American Sign language

Discussion of changing RDA and accessibility content

RDA Steering Committee (RSC) is developing new RDA in 3R Project. And, RDA updates after 2017 version are continuing as beta version at RDA Toolkit beta site. RSC plans to switch over from the beta site to official RDA status at December 15, 2020.

• Statement on 3R Project Completion

Changing accessibility content was also the topic of discussion among RSC. RSC decided the policy of changing ‘accessibility content’ as belows in January 2020 meeting (see also “210 RDA Content Elements Follow-up” of PDF MINUTES OF JANUARY 2020 MEETING in detail).

accessibility content

Recommendation 2.2: Redefine Expression: accessibility content as a Manifestation shortcut
Shortcut:

1. Manifestation: expression manifested [for an expression that is aggregated]
2. Expression: category of expression [for a category of accessibility content taken from an unspecified VES]

Definition: An indication of the kinds of expression that provide alternative sensory modes to perceive the main expressions that are embodied by an augmentation aggregate.
Scope note: Accessibility content includes accessible labels, an audio description, captioning, image descriptions, sign language, and subtitles. Accessibility content does not include subtitles in a language different from the spoken content.
This is an element sub-type of Manifestation: supplementary content.
This shortcut allows information about accessibility of content and carrier to be recorded for a manifestation.

Future modified version of accessibility content

We can see the modified version of accessibility content according to the above policy at paper for discussion at the January 2020 “Appendices: Clean versions of new and amended Toolkit pages” as belows.

This version describes the element as a shortcut that uses an unspecified VES. This is consistent with other elements that are shortcuts or that use an unspecified VES. The content is complete.

accessibility content

Definition and scope

An indication of the kinds of expression that provide alternative sensory modes to perceive the main expressions that are embodied by an augmentation aggregate. Accessibility content includes accessible labels, an audio description, captioning, image descriptions, sign language, and subtitles. Accessibility content does not include subtitles in a language different from the spoken content.

Prerecording

This element applies to a manifestation that is an aggregate.
This element is a shortcut for the following chain of relationships:

1. Manifestation: expression manifested for an expression that is aggregated
2. Expression: category of expression for a kind of accessibility content

The element does not identify any expression that is aggregated.
For general guidance on shortcuts, see Guidance: Introduction to RDA. Relationship shortcuts

Recording

Recording an unstructured description

OPTION: Record an uncontrolled term or a term that is transcribed from a source of information.
OPTION : Record details or other unstructured information.
For general guidance on unstructured descriptions, see Guidance: Recording methods. Recording an unstructured description.

Recording a structured description

OPTION: Record a term from a suitable vocabulary encoding scheme.
OPTION: Record a vocabulary encoding scheme that is used as a source of information for a term. For general guidance, see Guidance: Data provenance. Recording a source of metadata.
CONDITION: None of the terms in a vocabulary encoding scheme is appropriate or sufficiently specific.
　　　OPTION : Record a suitable uncontrolled term as an unstructured description.
Record a term from a suitable vocabulary encoding scheme. Appendix 5 For general guidance on structured descriptions, see Guidance: Recording methods. Recording a structured description.

Recording an identifier

OPTION: Record an identifier or notation for a term from a suitable vocabulary encoding scheme.
OPTION: Record a vocabulary encoding scheme that is used as a source of information for an identifier. For general guidance, see Guidance: Data provenance. Recording a source of metadata.
For general guidance on identifiers, see Guidance: Recording methods. Recording an identifier.

Recording an IRI

OPTION: Record an IRI for a term or concept as a real-world object selected from a suitable vocabulary encoding scheme.
For general guidance on IRIs, see Guidance: Recording methods. Recording an IRI.

Related elements

Main points of modification is as follows:

1. Redfined as a Manifestation element.
2. “Recording a structured description”,”Recording an identifier” and “Recording an IRI” which say “This recording method is not applicable to this element.” at current RDA Toolkit beta are changed to applicable items.

Is Change 2　supposed that accessibility content support ‘341’ fields of MARC21 ?

Future plans of accessibility content

From PDF MINUTES OF JANUARY 2020 MEETING .

ACTION ITEM: Dunsire will adjust the RDA text in the CMS to accommodate these recommendations in time for the next Toolkit release.

　先のエントリのとおり、RDA (Resource Description and Access)は、accessibility contentは表現形（Expression）の内容要素（content element）として規定しています（『日本目録規則 2018年版』でも同様）。
　しかし、表現形（Expression）のレベルだと、例えば、夏目漱石の『坊っちゃん』（日本語）を例にあげるなら、以下は、一括で1つの表現形として扱われます。

• ハードカバーで刊行された『坊っちゃん』（日本語）
• 文庫本でで刊行された『坊っちゃん』（日本語）
• 大活字本として刊行された『坊っちゃん』（日本語）
• 電子書籍で刊行された『坊っちゃん』（日本語）

　大活字本なら大活字本であることがアクセシビリティに関する情報として必要ですし、電子書籍なら読み上げが可能かどうかがアクセシビリティに関する情報としては重要です。アクセシビリティに関するメタデータは、表現形 ではなく、それがより具体化された体現形 (Manifestation) でないと、記述することが難しいのでは、という疑問を感じつつ、RDA Steering Committee (RSC) での議論を追っていくと、まさにaccessibility contentの変更が議論されて、近く大きな変更がなされるようなので、まとめました（なお、表現形（Expression）、体現形 (Manifestation) については、『日本目録規則2018年版』の「第 1 部 総説」3/18ページから4/18ページ参照）。
　
　公開された情報を確認する限り、2019年のSantiagoのRSC会議で一度話し合われて結論が出ず（議事録[PDF]の項番184参照）、Basecampやドキュメントベースの議論を経て、2020年1月に開催されたRSCの非同期会議（Asynchronous meeting）で決着がついた（議事録[PDF]の項番210参照）、という流れのようです。
　RSCの2019年10月と2020年1月の会議資料一式と議事録は以下で公開されています。

• RSC Papers
  　なお、先のエントリでは、現行版Toolkitの表記に合わせてAccessibility contentと表記していましたが、本エントリでは、Toolkitベータ版の表記にあわせてaccessibility content とします。

1. accessibility contentの変更方針

　accessibility content は以下のとおり、表現形で使用される要素から体現形で使用される要素に再定義され、ショートカット(expression manifested要素とcategory of expression要素)で体現形と表現形を関連付けるものに変更されることで、RSC内で承認されたようです（2020年1月会議議事録[PDF]の項番210及び22/30〜23/30ページ参照）。
Recommendation 2: Relocate the content elements to the Manifestation entity.
　　Recommendation2.2: Redefine Expression: accessibility content as a Manifestation shortcut
　
　accessibility content の具体的な変更内容は、以下のとおり（議事録 22/30〜23/30ページ)から転載。

accessibility content

Recommendation 2.2: Redefine Expression: accessibility content as a Manifestation shortcut
Shortcut:

1. Manifestation: expression manifested [for an expression that is aggregated]
2. Expression: category of expression [for a category of accessibility content taken from an unspecified VES]

Definition: An indication of the kinds of expression that provide alternative sensory modes to perceive the main expressions that are embodied by an augmentation aggregate.
Scope note: Accessibility content includes accessible labels, an audio description, captioning, image descriptions, sign language, and subtitles. Accessibility content does not include subtitles in a language different from the spoken content.
This is an element sub-type of Manifestation: supplementary content.
This shortcut allows information about accessibility of content and carrier to be recorded for a manifestation.

2. 改定後のRDA Toolkit accessibility content文案

　上の方針で変更方針にそったRDA Toolkit上でのaccessibility content文案も2020年1月の会議資料（[PDF]Appendices: Clean versions of new and amended Toolkit pagesの”Appendix 5: Clean version of Manifestation: accessibility content”より）で示されていますので、以下に転載します。

This version describes the element as a shortcut that uses an unspecified VES. This is consistent with other elements that are shortcuts or that use an unspecified VES. The content is complete.

accessibility content

Definition and scope

An indication of the kinds of expression that provide alternative sensory modes to perceive the main expressions that are embodied by an augmentation aggregate. Accessibility content includes accessible labels, an audio description, captioning, image descriptions, sign language, and subtitles. Accessibility content does not include subtitles in a language different from the spoken content.

Prerecording

This element applies to a manifestation that is an aggregate.
This element is a shortcut for the following chain of relationships:

1. Manifestation: expression manifested for an expression that is aggregated
2. Expression: category of expression for a kind of accessibility content

The element does not identify any expression that is aggregated.
For general guidance on shortcuts, see Guidance: Introduction to RDA. Relationship shortcuts

Recording

Recording an unstructured description

OPTION: Record an uncontrolled term or a term that is transcribed from a source of information.
OPTION : Record details or other unstructured information.
For general guidance on unstructured descriptions, see Guidance: Recording methods. Recording an unstructured description.

Recording a structured description

OPTION: Record a term from a suitable vocabulary encoding scheme.
OPTION: Record a vocabulary encoding scheme that is used as a source of information for a term. For general guidance, see Guidance: Data provenance. Recording a source of metadata.
CONDITION: None of the terms in a vocabulary encoding scheme is appropriate or sufficiently specific.
　　　OPTION : Record a suitable uncontrolled term as an unstructured description.
Record a term from a suitable vocabulary encoding scheme. Appendix 5 For general guidance on structured descriptions, see Guidance: Recording methods. Recording a structured description.

Recording an identifier

OPTION: Record an identifier or notation for a term from a suitable vocabulary encoding scheme.
OPTION: Record a vocabulary encoding scheme that is used as a source of information for an identifier. For general guidance, see Guidance: Data provenance. Recording a source of metadata.
For general guidance on identifiers, see Guidance: Recording methods. Recording an identifier.

Recording an IRI

OPTION: Record an IRI for a term or concept as a real-world object selected from a suitable vocabulary encoding scheme.
For general guidance on IRIs, see Guidance: Recording methods. Recording an IRI.

Related elements

3. Recording（記録のとり方）の変更が大きい？

　先のエントリのとおり、”Record”の”Recording a structured description”、”Recording an identifier”、”Recording an IRI”は現行では、RDAはベータ版においても、accessibility contentは適用対象外としていましたが、上の改定文案では、適用対象となり、記録のとり方が追記されました。MARC 21の341にも対応したという理解でよいのかな（よくわからない）？
　Recording の変更については、1. accessibility contentの変更方針で紹介した変更方針では特に言及されていませんが、2019年10月会議（2020年1月会議議事録[PDF]の項番184参照）で、RDA外のボキャブラリーの適用について以下のような議論があり、アクセシビリティはよいテストケースになるという意見が出ています。これが反映されたのかもしれない。

172.4　Vocabulary extensions outside of RDA:
RSC policy is to allow alternative vocabulary encoding schemes (VESs); RDA already includes the books of the Bible and medium of performance in the Resources tab. A conventional collective title VES could also be added here. RSC may get requests from communities to add alternative VESs. Hennelly notes that someone (or some group) must take responsibility for all Toolkit content. There must be some controls, and there may be a cost. Amey is concerned about the ability of communities to maintain this type of content. Kartus suggested that a test case may be a VES for accessibility.
It could go into the Documents area, but if an organization owns and maintains it, it could fit into the Registry or under Policies. Dunsire reminded the group that Toolkit can point to external resources.

4. 今後

　2020年1月会議議事録[PDF]（4/30ページ）でRecommendation 2（Relocate the content elements to the Manifestation entity）を以下のとおり承認したということで、次のToolkit リリースのタイミングで反映されるっぽい。

The RSC generally supported recommendations 2-4 and the relevant parts of 5. Dunsire suggested that it is important to apply these recommendations as soon as possible because of the impact on translators and policy statement writers.
ACTION ITEM: Dunsire will adjust the RDA text in the CMS to accommodate these recommendations in time for the next Toolkit release.