Updates to the Accessibility terms Registry

source/registry/accessibility/index.md

@@ -59,22 +59,24 @@ The process for having a new entry added to this registry is [described here][re
 
 ## 3. Registry
 
-This table summarizes the known values available for use with the [Presentation API][prezi-api] `provides` propery, which defines accessibility functionality that a linked resource enables for its target, describing why and how a client might use it rather than what the resource is by type or format. The current approved values are defined by Schema.org's [Accessibility Properties for Discoverability Vocabulary][schema-accessibility] and the IIIF Community.
-
-| Value                       | Description | Source |
-| ------------------------------ | |
-| `closedCaptions` | ... | Schema.org |
-| `alternativeText` | ... | Schema.org |
-| `audioDescription` | ... | Schema.org |
-| `longDescription` | ... | Schema.org |
-| `signLanguage` | ... | Schema.org |
-| `highContrastAudio` | ... | Schema.org |
-| `highContrastDisplay` | ... | Schema.org |
-| `braille` | ... | Schema.org |
-| `tactileGraphic` | ... | Schema.org |
-| `transcript` | ... | Schema.org |
-| `translation` | ... | IIIF |
-| `subtitles` | ... | IIIF |
+This table summarizes the known values available for use with the [Presentation API][prezi-api] `provides` property, which defines accessibility functionality that a linked resource enables for its target, describing why and how a client might use it rather than what the resource is by type or format.
+
+The definitions in this table are the definitions of the values for use with `provides`. Where a value originates in an external source, principally the [Accessibility Properties for Discoverability Vocabulary][schema-accessibility] published by the W3C Accessibility Discoverability Vocabulary for Schema.org Community Group, but also others, the Source column links to the original term for reference only; the definition given here takes precedence. Values with the source IIIF are defined by the IIIF Community.
+
+| Value | Definition | Source |
+| ----- | ---------- | ------ |
+| `closedCaptions`{: #closedCaptions} | Synchronized text of the dialogue together with descriptions of sound effects, relevant musical cues and other relevant audio information. Content that transcribes only the dialogue is `subtitles`. | Adapted from [W3C a11y-discov-vocab CG, §4.2.2.4](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#closedCaptions) |
+| `alternativeText`{: #alternativeText} | Textual content to be provided to users that cannot or do not wish to interact with the image, audio or video file directly. | Adapted from [W3C a11y-discov-vocab CG, §4.2.2.1](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#alternativeText) |
+| `audioDescription`{: #audioDescription} | Audio narration that describes the visual content of a video or image, for users who cannot see it. | Adapted from [W3C a11y-discov-vocab CG, §4.2.2.2](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#audioDescription) |
+| `longDescription`{: #longDescription} | A textual representation of visual, auditory or complex structured data. | Adapted from [W3C a11y-discov-vocab CG, §4.2.2.6](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#longDescription) |
+| `signLanguage`{: #signLanguage} | A sign language interpretation of audio or video content. | Adapted from [W3C a11y-discov-vocab CG, §4.2.2.8](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#signLanguage) |
+| `highContrastAudio`{: #highContrastAudio} | An alternative form of the audio where the contrast is high, making it easier to hear. | Adapted from [W3C a11y-discov-vocab CG, §4.2.5.1](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#highContrastAudio) |
+| `highContrastDisplay`{: #highContrastDisplay} | An alternative form of visual content where the contrast is high, making it easier to see. | Adapted from [W3C a11y-discov-vocab CG, §4.2.5.2](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#highContrastDisplay) |
+| `braille`{: #braille} | A braille representation of the content. | Adapted from [W3C a11y-discov-vocab CG, §4.2.6.1](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#braille) |
+| `tactileGraphic`{: #tactileGraphic} | A tactile graphic version of visual content, for users who read by touch. | Adapted from [W3C a11y-discov-vocab CG, §4.2.6.2](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#tactileGraphic) |
+| `transcript`{: #transcript} | A text transcription of the content of the resource, which is not necessarily synchronized with it. | Adapted from [W3C a11y-discov-vocab CG, §4.2.2.9](https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#transcript) |
+| `translation`{: #translation} | A translation of the content into another language. | IIIF |
+| `subtitles`{: #subtitles} | A transcription or translation of the dialogue only, synchronized with audio or video content. It does not include descriptions of sound effects, music or other non-speech audio; content that does is `closedCaptions`. | Adapted from [HTML Standard, `track` `kind` subtitles](https://html.spec.whatwg.org/multipage/media.html#attr-track-kind-subtitles) |
 {: .api-table}
 
 
@@ -88,7 +90,7 @@ Thanks to the members of the [IIIF][iiif-community] for their continuous engagem
 
 | Date       | Description                                        |
 | ---------- | -------------------------------------------------- |
-| 2026-XX-YY | New Version 4 Registries                           |
+| 2026-11-04 | New Presentation 4 `provides` Properties           |
 
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