IIIF · kirschbombe · Jan 14, 2026 · Jan 14, 2026 · Jan 14, 2026 · tomcrane
diff --git a/source/_includes/links.md b/source/_includes/links.md
@@ -279,6 +279,7 @@
 [navPlace]: {{ site.api_url | absolute_url }}/extension/navplace/
 [georeference]: {{ site.api_url | absolute_url }}/extension/georef/
 [registry]: {{ site.api_url | absolute_url }}/registry/ "IIIF Extension Registry"
+[registry-accessibility]: {{ site.api_url | absolute_url }}/registry/accessibility/
 [registry-activity-streams]: https://registry.iiif.io/ "IIIF Registry of Activity Streams"
 [registry-motivations]: {{ site.api_url | absolute_url }}/registry/motivations/
 [registry-behaviors]: {{ site.api_url | absolute_url }}/registry/behaviors/
@@ -304,5 +305,6 @@
 [recipe-process]: {{  site.cookbook_url | absolute_url }}/recipe/ "Cookbook process"
 [recipe-mvm-image]: {{ site.cookbook_url | absolute_url }}/recipe/0001-mvm-image/ "Simplest Manifest - Image"
 [recipe-segment-image-part]: {{ site.api_url | absolute_url }}/cookbook/segment-image-part/ "Annotating part of an image to a canvas"
+[schema-accessibility]: https://www.w3.org/community/reports/a11y-discov-vocab/CG-FINAL-vocabulary-20241209/#accessibilityFeature-vocabulary "Accessibility Properties for Discoverability Vocabulary"
 [slack]: http://bit.ly/iiif-slack
 [web-arch]: http://www.w3.org/TR/webarch/ "Architecture of the World Wide Web"
diff --git a/source/presentation/4.0/index.md b/source/presentation/4.0/index.md
@@ -998,7 +998,7 @@ This example is a Manifest with two Timelines, each of which represent a tempora
 
 >
 **Key Points**
-* t vs. instant / verbose vs. append to URI???
+* In the external annotation for the song lyrics, we append `#t=3.5,6.8` to the target URI to define the temporal extent in the target timeline that corresponds to the song lyric.
 {: .note}
 
 !!! warning TODO: The above should be a green class rgb(244,252,239) to distinguish from properties
@@ -1102,11 +1102,11 @@ This example is a Manifest with one Canvas that represents the temporal extent o
               "id": "https://example.org/iiif/presentation/examples/manifest-with-movie/subtitles/anno",
               "type": "Annotation",
               "motivation": "supplementing",
+              "provides": [ "subtitles" ],
               "body": {
                 "id": "https://example.org/text/subtitles.vtt",
                 "type": "Text",
                 "format": "text/vtt",
-                "provides": [ "subtitles" ],
                 "label": {
                   "en": [
                     "Subtitles in WebVTT format"
@@ -2640,13 +2640,44 @@ Responses _SHOULD_ be compressed by the server as there are significant performa
 
 # Accessibility
 
-(new section)
+Some IIIF resources have associated resources, such as closed-caption files for video, audio descriptions for images, or tactile graphics for visual materials, that improve access to the content for a wider range of users. These linked resources play a specific accessibility-related role relative to the resource they describe or supplement. See [A/V Use Case 5: Movie with subtitles](link to section) above.
 
-`provides`
-`provides[]`
+IIIF uses the `provides` property on supplementing annotations to define the specific 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. For example, a text file linked from a video might provide closedCaptions, or an audio file associated with a Canvas might provide an audioDescription.
 
+The value of provides _MUST_ be an array of strings. Each string _MUST_ be taken from the [IIIF Registry of Accessibility Values][schema-accessibility].
 
+Annotations MAY include the provides property only when the annotation has the supplementing motivation.
+Clients SHOULD ignore the provides property on resources with any other motivation.
 
+```json
+"annotations": [
+  {
+    "id": "https://example.org/iiif/presentation/examples/manifest-with-movie/subtitles",
+    "type": "AnnotationPage",
+    "items": [
+      {
+        "id": "https://example.org/iiif/presentation/examples/manifest-with-movie/subtitles/anno",
+        "type": "Annotation",
+        "motivation": "supplementing",
+        "provides": [ "alternativeText" ],
+        "body": {...},
+        "target": "https://example.org/iiif/presentation/examples/manifest-with-movie/canvas"
+      }
+    ]
+  }
+]
+```
+
+**Key Points**
+* The `provides` property is placed on the annotation and not on the target of the annotation.
+* The property is primarly used to define accessibility features, but can be used to define other types of functionality, such as `transcription`.
+{: .note}
+
+!!! warning TODO: The above should be a green class rgb(244,252,239) to distinguish from properties
+
+__Definitions__<br/>
+Properties: [provides](#model/provides)
+{: .note}
 
 
 

diff --git a/source/registry/accessibility/index.md b/source/registry/accessibility/index.md
@@ -0,0 +1,94 @@
+---
+title: Registry of Accessibility Values
+layout: spec
+tags: [annex, service, services, specifications]
+cssversion: 2
+editors:
+  - name: Michael Appleby
+    ORCID: https://orcid.org/0000-0002-1266-298X
+    institution: Yale University
+  - name: Dawn Childress
+    ORCID: https://orcid.org/0000-0003-2602-2788
+    institution: UCLA
+  - name: Tom Crane
+    ORCID: https://orcid.org/0000-0003-1881-243X
+    institution: Digirati
+  - name: Jeff Mixter
+    ORCID: https://orcid.org/0000-0002-8411-2952
+    institution: OCLC
+  - name: Robert Sanderson
+    ORCID: https://orcid.org/0000-0003-4441-6852
+    institution: Yale University
+  - name: Julie Winchester
+    ORCID: https://orcid.org/0000-0001-6578-764X
+    institution: Duke University
+---
+
+## Status of this Document
+{:.no_toc}
+
+This document is not subject to [semantic versioning][notes-versioning].
+Changes will be tracked within the document.
+
+**Editors:**
+
+{% include api/editors.md editors=page.editors %}
+
+{% include copyright.md %}
+
+## Abstract
+{:.no_toc}
+This document lists a set of allowed values for the Presentation API `provides` property that have been identified as useful for implementations, especially related to accessibility. They may be defined by the IIIF community, or outside of it.
+
+Please send feedback to [iiif-discuss@googlegroups.com][iiif-discuss]
+
+
+## 1. Introduction
+
+This is one of a number of [IIIF registries][registry]. It lists a set of allowed values for the Presentation API `provides` property that have been identified as useful for implementations, especially related to accessibility. They may be defined by the IIIF community, or outside of it.
+
+### 1.1. Disclaimer
+
+The inclusion of entries in this document that are outside of the IIIF domain _MUST NOT_ be interpreted as endorsement, support, or approval from the editors, the IIIF community or any individual. This annex is provided as a registry to advertise the existence of these extensions and attempt to ensure some consistency between implementations for common but not universal requirements.
+
+### 1.2. Inclusion Process
+
+The process for having a new entry added to this registry is [described here][registry-process].
+
+## 2. Requirements for Inclusion
+
+## 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 |
+{: .api-table}
+
+
+## Appendices
+
+### A. Acknowledgements
+
+Thanks to the members of the [IIIF][iiif-community] for their continuous engagement, innovative ideas and feedback.
+
+### B. Change Log
+
+| Date       | Description                                        |
+| ---------- | -------------------------------------------------- |
+| 2026-XX-YY | New Version 4 Registries                           |
+
+{% include acronyms.md %}
+{% include links.md %}
diff --git a/source/registry/index.md b/source/registry/index.md
@@ -13,6 +13,7 @@ The process for having an entry included in one of the IIIF extension registries
 
 ## Presentation API Registries
 
+* [Accessibility Terms][registry-accessibility]
 * [Behaviors][registry-behaviors]
 * [Presentation API Extensions][extensions]
 * [Motivations][registry-motivations]