Personalization Semantics Explainer 1.0

W3C Working Draft

This version:
Latest published version:
Latest editor's draft:
Previous version:
Lisa Seeman,
Charles LaPierre, Benetech,
Rich Schwerdtfeger
Michael Cooper, W3C,
Roy Ran, W3C,


Personalization involves tailoring aspects of the user experience to meet the needs and preferences of the user. For example, having familiar terms and symbols is key to many users being able to use the web. However, what is familiar for one user may be unfamiliar to another requiring them to learn new symbols. The challenge has been the ability to identify the types of content in a document that should be adapted to the preferred user experience. The introduction of standardized semantics allows web applications to customize the exposure of that content to one that is familiar to individuals based on their needs and preferences. This specification defines standard semantics to enable user driven personalization such as the association of user-preferred symbols to elements having those semantics. This ensures that users can quickly find familiar icons, such as a help icon, that apply to user interface elements.

This document is an explanation for understanding how to use Personalization properties to personalize an accessible web site.

Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at

This is a Working Draft of Personalization Semantics Explainer 1.0 by the Accessible Rich Internet Applications Working Group. This specification changes from the previous version to introduce personalization semantics modules. This explainer introduces standard semantics to enable user-driven personalization, such as the association of a user-preferred symbols to elements having those semantics. The modules define features for specific categories of personalization. Adaptable Content, Adaptable Help and Support and Adaptable Tools. The Content module is published at the same time as this document, and the other modules will be published in the future. This version adds a Vocabulary Identification section, does some changes in sections of WAI-ARIA and HTML Microdata, also replaces the RDFa section with editor's note.

To comment, file an issue in the W3C personalization semantics GitHub repository. If this is not feasible, send email to (archives). Comments are requested by 13 April 2018. In-progress updates to the document may be viewed in the publicly visible editors' draft.

Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document was produced by a group operating under the W3C Patent Policy. The group does not expect this document to become a W3C Recommendation. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

This document is governed by the 1 February 2018 W3C Process Document.

1. Introduction

This section is non-normative.

The goals of this specification includes:

This is a proposal to define syntax for adaptable content such as: links, buttons, symbols, help and keyboard. This may be an WAI-ARIA COGA Extension.

Personalization involves tailoring aspects of the user experience to meet the preferences or needs of the user. For example, having familiar terms and symbols is key to being able to use the web. However what is familiar for one user may be new for another requiring them to learn new symbols. Personalization could include loading a set of symbols that is appropriate for the specific user, ensuring that all users find the icons simple and familiar.

Technology holds the promise of being extremely flexible and the design of many systems includes the expectation that users will be able to optimize their interaction experience according to their personal preferences or accessibility requirements (needs).

1.1 Why We Need Personalization

We need personalization because:

Some users need extra support. This can include:

For this we need standardized terms and supportive syntax that can be linked to associated symbols, terms, translations and explanations for the individual use via an attribute and personal preferences.

For example, assume an author can make it programanticaly known that a button is used to send an email. At the user end, the button could be rendered with a symbol, term, and/or tooltips that are understandable for this particular user. It could automatically apply F1 help that explains the send function in simple terms. It could be identified with a keyboard short cut that will always be used for send. In addition it could be identified as important and always rendered, or rendered as a large button.

Working examples of how this could be used in practice, with user preferences, are available on the task force implementations page.

In another use-case we would like to see interoperable symbol set codes for non-verbal people. Products for people who are non-vocal often use symbols to help users communicate. These symbols are in fact an individuals language. Unfortunately many of these symbols are both subject to copyright and are not interoperable. That means end-users can only use one device, and can not use applications or assistive technologies from a different company. An open set of references for symbol codes for these symbol sets however, could be interoperable. That means the end user could use an open source symbol set or buy the symbols and use them across different devices or applications. Symbols could still be proprietary but they would also be interoperable.

1.2 Personalization Use Cases (general)

Personalization Use Cases covers use cases that can be addressed by personalization, and references the vocabulary items that help meet the use cases.

2. Important Terms

While some terms are defined in place, the following definitions are used throughout this document.

Accessibility API

Operating systems and other platforms provide a set of interfaces that expose information about objects and events to assistive technologies. Assistive technologies use these interfaces to get information about and interact with those widgets. Examples of accessibility APIs are Microsoft Active Accessibility [MSAA], Microsoft User Interface Automation [UI-AUTOMATION], MSAA with UIA Express [UIA-EXPRESS], the Mac OS X Accessibility Protocol [AXAPI], the Linux/Unix Accessibility Toolkit [ATK] and Assistive Technology Service Provider Interface [AT-SPI], and IAccessible2 [IAccessible2].

Accessibility Subtree

An accessible object in the accessibility tree and its descendants in that tree. It does not include objects which have relationships other than parent-child in that tree. For example, it does not include objects linked via aria-flowto unless those objects are also descendants in the accessibility tree.

Accessibility Tree

Tree of accessible objects that represents the structure of the user interface (UI). Each node in the accessibility tree represents an element in the UI as exposed through the accessibility API; for example, a push button, a check box, or container.

Accessible Description

An accessible description provides additional information, related to an interface element, that complements the accessible name. The accessible description might or might not be visually perceivable.

Accessible Name

The accessible name is the name of a user interface element. Each platform accessibility API provides the accessible name property. The value of the accessible name may be derived from a visible (e.g., the visible text on a button) or invisible (e.g., the text alternative that describes an icon) property of the user interface element. See related accessible description.

A simple use for the accessible name property may be illustrated by an "OK" button. The text "OK" is the accessible name. When the button receives focus, assistive technologies may concatenate the platform's role description with the accessible name. For example, a screen reader may speak "push-button OK" or "OK button". The order of concatenation and specifics of the role description (e.g., "button", "push-button", "clickable button") are determined by platform accessibility APIs or assistive technologies.

Accessible object

A node in the accessibility tree of a platform accessibility API. Accessible objects expose various states, properties, and events for use by assistive technologies. In the context of markup languages (e.g., HTML and SVG) in general, and of WAI-ARIA in particular, markup elements and their attributes are represented as accessible objects.

Activation behavior

The action taken when an event, typically initiated by users through an input device, causes an element to fulfill a defined role. The role may be defined for that element by the host language, or by author-defined variables, or both. The role for any given element may be a generic action, or may be unique to that element. For example, the activation behavior of an HTML or SVG <a> element shall be to cause the user agent to traverse the link specified in the href attribute, with the further optional parameter of specifying the browsing context for the traversal (such as the current window or tab, a named window, or a new window); the activation behavior of an HTML <input> element with the type attribute value submit shall be to send the values of the form elements to an author-defined IRI by the author-defined HTTP method.

Assistive Technologies

Hardware and/or software that:

  • relies on services provided by a user agent to retrieve and render Web content
  • works with a user agent or web content itself through the use of APIs, and
  • provides services beyond those offered by the user agent to facilitate user interaction with web content by people with disabilities

This definition may differ from that used in other documents.

Examples of assistive technologies that are important in the context of this document include the following:

  • screen magnifiers, which are used to enlarge and improve the visual readability of rendered text and images;
  • screen readers, which are most-often used to convey information through synthesized speech or a refreshable Braille display;
  • text-to-speech software, which is used to convert text into synthetic speech;
  • speech recognition software, which is used to allow spoken control and dictation;
  • alternate input technologies (including head pointers, on-screen keyboards, single switches, and sip/puff devices), which are used to simulate the keyboard;
  • alternate pointing devices, which are used to simulate mouse pointing and clicking.

In this specification, attribute is used as it is in markup languages. Attributes are structural features added to elements to provide information about the states and properties of the object represented by the element.


A set of instance objects that share similar characteristics.


A deprecated role, state, or property is one which has been outdated by newer constructs or changed circumstances, and which may be removed in future versions of the WAI-ARIA specification. User agents are encouraged to continue to support items identified as deprecated for backward compatibility. For more information, see Deprecated Requirements in the Conformance section.

Desktop focus event

Event from/to the host operating system via the accessibility API, notifying of a change of input focus.


In this specification, element is used as it is in markup languages. Elements are the structural elements in markup language that contains the data profile for objects.


A programmatic message used to communicate discrete changes in the state of an object to other objects in a computational system. User input to a web page is commonly mediated through abstract events that describe the interaction and can provide notice of changes to the state of a document object. In some programming languages, events are more commonly known as notifications.


Translated to platform-specific accessibility APIs as defined in the WAI-ARIA User Agent Implementation Guide. [WAI-ARIA-IMPLEMENTATION]

Graphical Document

A document containing graphic representations with user-navigable parts. Charts, maps, diagrams, blueprints, and dashboards are examples of graphical documents. A graphical document is composed using any combination of symbols, images, text, and graphic primitives (shapes such as circles, points, lines, paths, rectangles, etc).


Indicates that the element is not visible, perceivable, or interactive to any user. An element is considered hidden if it or any one of its ancestor elements is not rendered or is explicitly hidden.


Content provided for information purposes and not required for conformance. Content required for conformance is referred to as normative.

Keyboard Accessible

Accessible to the user using a keyboard or assistive technologies that mimic keyboard input, such as a sip and puff tube. References in this document relate to WCAG 2.0 Guideline 2.1: Make all functionality available from a keyboard [WCAG20].


A type of region on a page to which the user may want quick access. Content in such a region is different from that of other regions on the page and relevant to a specific user purpose, such as navigating, searching, perusing the primary content, etc.

Live Region

Live regions are perceivable regions of a web page that are typically updated as a result of an external event when user focus may be elsewhere. These regions are not always updated as a result of a user interaction. This practice has become commonplace with the growing use of Ajax. Examples of live regions include a chat log, stock ticker, or a sport scoring section that updates periodically to reflect game statistics. Since these asynchronous areas are expected to update outside the user's area of focus, assistive technologies such as screen readers have either been unaware of their existence or unable to process them for the user. WAI-ARIA has provided a collection of properties that allow the author to identify these live regions and process them: aria-live, aria-relevant, aria-atomic, and aria-busy. Pre-defined live region roles are listed in the Choosing Between Special Case Live Regions ([WAI-ARIA-PRACTICES], Section 5.3).

Primary Content Element

An implementing host language's primary content element, such as the body element in HTML.

Managed State

Accessibility API state that is controlled by the user agent, such as focus and selection. These are contrasted with "unmanaged states" that are typically controlled by the author. Nevertheless, authors can override some managed states, such as aria-posinset and aria-setsize. Many managed states have corresponding CSS pseudo-classes, such as :focus, and pseudo-elements, such as :selection, that are also updated by the user agent.

Nemeth Braille

The Nemeth Braille Code for Mathematics is a braille code for encoding mathematical and scientific notation. See Nemeth Braille on Wikipedia.


Basic type of object in the DOM tree or accessibility tree. DOM nodes are further specified as Element or Text nodes, among other types. The nodes of an accessibility tree are accessible objects.


Required for conformance. By contrast, content identified as informative or "non-normative" is not required for conformance.


In the context of user interfaces, an item in the perceptual user experience, represented in markup languages by one or more elements, and rendered by user agents.

In the context of programming, the instantiation of one or more classes and interfaces which define the general characteristics of similar objects. An object in an accessibility API may represent one or more DOM objects. Accessibility APIs have defined interfaces that are distinct from DOM interfaces.

A description of the characteristics of classes and how they relate to each other.


Usable by users in ways they can control. References in this document relate to WCAG 2.0 Principle 2: Content must be operable [WCAG20]. See Keyboard Accessible.

Owned Element

An 'owned element' is any DOM descendant of the element, any element specified as a child via aria-owns, or any DOM descendant of the owned child.

Owning Element

An 'owning element' is any DOM ancestor of the element, or any element with an aria-owns attribute which references the ID of the element.


Presentable to users in ways they can sense. References in this document relate to WCAG 2.0 Principle 1: Content must be perceivable [WCAG20].


Attributes that are essential to the nature of a given object, or that represent a data value associated with the object. A change of a property may significantly impact the meaning or presentation of an object. Certain properties (for example, aria-multiline) are less likely to change than states, but note that the frequency of change difference is not a rule. A few properties, such as aria-activedescendant, aria-valuenow, and aria-valuetext are expected to change often. See clarification of states versus properties.


A connection between two distinct things. Relationships may be of various types to indicate which object labels another, controls another, etc.


Main indicator of type. This semantic association allows tools to present and support interaction with the object in a manner that is consistent with user expectations about other objects of that type.

Root WAI-ARIA node

The primary element containing non-metadata content. In many languages, this is the document element but in HTML, it is the <body>.


The meaning of something as understood by a human, defined in a way that computers can process a representation of an object, such as elements and attributes, and reliably represent the object in a way that various humans will achieve a mutually consistent understanding of the object.


A state is a dynamic property expressing characteristics of an object that may change in response to user action or automated processes. States do not affect the essential nature of the object, but represent data associated with the object or user interaction possibilities. See clarification of states versus properties.


Any document created from a <frame>, <iframe> or similar mechanism. A sub-document may contain a document, an application or any widget such as a calendar pulled in from another server. In the accessibility tree there are two accessible objects for this situation—one represents the <frame>/<iframe> element in the parent document, which parents a single accessible object child representing the spawned document contents.

Target Element

An element specified in a WAI-ARIA relation. For example, in <div aria-controls=”elem1”>, where “elem1” is the ID for the target element.


A hierarchical definition of how the characteristics of various classes relate to each other, in which classes inherit the properties of superclasses in the hierarchy. A taxonomy can comprise part of the formal definition of an ontology.

Text node

Type of DOM node that represents the textual content of an attribute or an element. A Text node has no child nodes.


Presentable to users in ways they can construct an appropriate meaning. References in this document relate to WCAG 2.0 Principle 3: Information and the operation of user interface must be understandable [WCAG20].

User Agent

Any software that retrieves, renders and facilitates end user interaction with Web content. This definition may differ from that used in other documents.


A reference to a target element in the same document that has a matching ID


Discrete user interface object with which the user can interact. Widgets range from simple objects that have one value or operation (e.g., check boxes and menu items), to complex objects that contain many managed sub-objects (e.g., trees and grids).

3. Structure of Properties

Semantic properties have the characteristics described in the following sections.

3.1 Value

Value type of the semantic property. The value may be one of the following types:

Value representing either true or false, with a default "false" value.
Value representing true or false, with a default "undefined" value indicating the state or property is not relevant.
ID reference
Reference to the ID of another element in the same document
ID reference list
A list of one or more ID references.
A numerical value without a fractional component.
Any real numerical value.
Unconstrained value type.
One of a limited set of allowed values.
token list
A list of one or more tokens.
A Uniform Resource Identifier as defined by RFC 3986 [RFC3986]. It may reference a separate document, or a content fragment identifier in a separate document, or a content fragment identifier within the same document.

The "undefined" value, when allowed on a state or property, is an explicit indication that the state or property is not set. The value is used on states and properties that support tokens, and the "undefined" value is a string that is one of the allowed tokens. It is also used on some states and properties that accept true/false values, when "undefined" has a different meaning than "false".

These are generic types for states and properties, but do not define specific representation. See State and Property Attribute Processing for details on how these values are expressed and handled in host languages.

4. Modules

This specification has been divided into modules.

Each module has use cases and vocabularies:

A. Vocabulary Implementations

A.1 Mapping Values to Different Syntax

A.2 Vocabulary Identification

Metadata languages that support this vocabulary need to distinguish terms coming from the personalization semantics vocabulary, from terms in other vocabularies. This document proposes two identifications mechanisms, which may be used separately or together according to the needs of the metadata language. These are the prefix and the identification URI.

A.2.1 Prefix

The prefix for personalization semantics is "aui", which is an acronym of "accessible user interface". Implementations that use a prefix to identify terms from this vocabulary should use that prefix.

A.2.2 Identification URI

The identification URI for personalization semantics is Implementations that use a URI to identify terms from this vocabulary should use that URI.


Properties in this case can be represented as WAI-ARIA properties by adding the prefix "aui-" to the attribute name, and the property value as the attribute value.

Editor's note

The prefix above is not yet accepted by the ARIA Working Group.

Example 1: Action Using ARIA
For example: <button aui-action="undo" >Revert</button>
Example 2: Destination Using ARIA
<a href="home.html" aui-destination="home">our main page</a>
Example 3: Fields Using ARIA
<input type="text" name="fname" aui-field="phone"/>
Example 4 Context Using ARIA
<a href="women.html" aui-context="">women</a>
Example 5 Symbol Using ARIA
<img aui-symbol="" href="mygirlsy.bmp"/>

A.3.1 Additional WAI-ARIA Roles

Requirement: We may want to add landmark role values for sections on a page such as: contact us - for a contact us form.

User experience: symbols and colors could be used consistently across different content.

Nav maps can be automatically generated for people learn via key-points or examples.

Further these sections could be hidden in the normal rendering of a page or rendered the top of page depending on user preferences. The location of these sections can also be changed, based on the user preference, enabling the user to find them easily.


  • summary
  • keypoints
  • example
  • note
  • warning
  • step
  • external - for external content, such as sponsored or advertising
  • offers - for special offers that are complementary to the main content or task
  • advertisement - advertisement or sponsored content
  • contact us
  • about us

A.4 HTML Microdata

Properties in this vocabulary can be applied via HTML Microdata [microdata]. To apply a term from this vocabulary to content using Microdata, use the following steps:

Example 1: Action property in HTML using HTML Microdata
<button itemscope itemtype="" itemprop="action" content="undo">

A.5 RDFa

Editor's note

The Personalization Task Force is exploring whether the personalization semantics vocabulary can be used with RDFa. If so, guidance will be added here in a future draft. See Issue 53.

A.6 Autocomplete

B. Acknowledgments

This section is non-normative.

The following people contributed to the development of this document.

B.1 Participants active in the Personalization TF at the time of publication

B.2 Other Personalization TF contributors, commenters, and previously active participants

B.3 Enabling funders

This publication has been funded in part with U.S. Federal funds from the Health and Human Services, National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) under contract number HHSP23301500054C. The content of this publication does not necessarily reflect the views or policies of the U.S. Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.

C. References

C.1 Informative references

Assistive Technology Service Provider Interface. The GNOME Project. URL:
ATK - Accessibility Toolkit. The GNOME Project. URL:
Accessibility Programming Guide for OS X. Apple Corporation. URL:
IAccessible2. Linux Foundation. URL:
HTML Microdata. Charles McCathie Nevile; Dan Brickley. W3C. 10 October 2017. W3C Working Draft. URL:
Microsoft Active Accessibility (MSAA) 2.0. Microsoft Corporation. URL:
Uniform Resource Identifier (URI): Generic Syntax. T. Berners-Lee; R. Fielding; L. Masinter. IETF. January 2005. Internet Standard. URL:
UI Automation. Microsoft Corporation. URL:
The IAccessibleEx Interface. Microsoft Corporation. URL:
WAI-ARIA 1.0 User Agent Implementation Guide. Joseph Scheuhammer; Michael Cooper. W3C. 20 March 2014. W3C Recommendation. URL:
WAI-ARIA 1.0 Authoring Practices. Joseph Scheuhammer; Michael Cooper. W3C. 14 July 2016. W3C Working Draft. URL:
Web Content Accessibility Guidelines (WCAG) 2.0. Ben Caldwell; Michael Cooper; Loretta Guarino Reid; Gregg Vanderheiden et al. W3C. 11 December 2008. W3C Recommendation. URL: