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Guidance on Applying WCAG 2.0 to Non-Web Information and Communications Technologies (WCAG2ICT) dfn { font-weight: bold; }

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.section dl.attrs dd, .section dl.eldef dd { margin-bottom: 0; } .termref { text-decoration:none; color: inherit; background-color: inherit; border-bottom:dotted #585858 thin; /* de-emphasize glossary links */ } a.termref:link, a.termref:visited { color: inherit; background : inherit; } a.termref:hover, .termref:active, a.termref:focus { color:#0000CC; background : inherit; } p.prefix { margin: 0.25em 0 0.5em 0; padding:0; } div.sc div.note p.prefix { margin-bottom: 0; } h4, h5 { color: #005a9c; } h4 { } h5 { font-weight: bold !important; } h6 { } blockquote { margin: 0 0 0 2em; font-size: 90%; background-color: #ffd; border: thin outset #ffd; padding: .5em; } ins, del { color: #EE0000; font-weight: bold; } ins { text-decoration: none; } ins::before { content: '['; } ins::after { content: ']'; } del { text-decoration: line-through; } .wcag2ict_termref { text-decoration:none; color: inherit; background-color: inherit; border-bottom:dashed #090 thin; /* de-emphasize glossary links */ } a.wcag2ict_termref:link, a.wcag2ict_termref:visited { color: inherit; background : inherit; } a.wcag2ict_termref:hover, .wcag2ict_termref:active, a.wcag2ict_termref:focus { color:#090; background : inherit; } a.termref cite, a.wcag2ict_termref cite { font-style: normal; } .note { margin-left: 1em; margin-bottom: 0.5em; border-color: inherit; background: inherit; border-left: none; } .ednote { border:solid 3px #cca; background-color:#ffd; padding:0 0.8em; } div.wcag2ict { display: block; margin-top: 1em; margin-bottom: 1em; padding: 1em 1em 1em 1.5em; background-color: #EEF; border-left: .5em solid #009; outline: thin solid #009; } div.wcag2ict h4, div.wcag2ict h5, div.wcag2ict h6 { color: #FFF; background-color: #009; margin-top: -1em; margin-left: -2em; margin-right: -1em; padding: .5ex; padding-left: 2em; font-weight: bold; font-style: normal; font-variant: normal; } div.principle, div.guideline, div.sc, div.glossary { margin-top: 4em; } div.redefinition { display: block; margin: 1em 0; padding: 1em; background-color: #FFF; border: thin solid #009; } p.redefinition-differentiator { margin-bottom: -1em; margin-top: 1em; font-weight: bold; } /* Overriding styles for the accordion */ Guidance on Applying WCAG 2.0 to Non-Web Information and Communications Technologies (WCAG2ICT) W3C Working Group Note This version: http://www.w3.org/TR/2013/NOTE-wcag2ict-20130905/ Latest version: http://www.w3.org/TR/wcag2ict/ Previous version: http://www.w3.org/TR/2013/WD-wcag2ict-20130711/ Latest editors' draft: http://www.w3.org/WAI/GL/wcag2ict/ Editors: Michael Cooper, W3C Peter Korn, Oracle Corporation Andi Snow-Weaver, IBM Corporation Gregg Vanderheiden, Invited Expert, Trace Research and Development Center Authors: Peter Korn, Oracle Corporation Loïc Martínez Normand, Universidad Politécnica de Madrid Mike Pluke, Invited Expert Andi Snow-Weaver, IBM Corporation Gregg Vanderheiden, Invited Expert, Trace Research and Development Center This document is available in an expandable / collapsible alternate version Copyright W3C ® MIT ERCIM Keio Beihang liability trademark document use Abstract This document, “ Guidance on Applying WCAG 2.0 to Non-Web Information and Communications Technologies Web Content Accessibility Guidelines (WCAG) 2.0 WCAG20 Information and Communications Technologies This document is a Working Group Note, and is part of a series of technical and educational documents published by the W3C WCAG 2.0 Overview 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 This document is a Working Group Note WCAG2ICT Task Force Work Statement Web Content Accessibility Guidelines Working Group Web Accessibility Initiative World Wide Web Consortium WCAG WG Charter scope This Working Group Note includes complete guidance for all Levels A and AA Success Criteria, guidance on all glossary terms plus new Key Terms, comments on conformance, and additional background information on some topics. This version includes changes made in response to comments received As a Working Group Note this content is stable, and the Working Group does not plan to make further changes. Should the need arise, however, the document could be updated. Comments received on this document will help the Working Group to decide if updates are needed, or will be taken into account should a republication be planned. Please send any comments on the “Additional Guidance” sections of this document to the public mailing list [email protected] This document includes many excerpts from “Understanding WCAG 2.0,” each of which is prefaced with the words “Intent from…” and which are also visually indicated with a yellow background. Understanding WCAG 2.0 and other WCAG 2.0 supporting documents will continue to focus on web technologies. For comments on Understanding WCAG, please follow the comment instructions in that document. Please note that WCAG 2.0 itself is a stable web standard. Comments on this document will not affect WCAG 2.0 wording. Publication as a Working Group Note This document was produced by a group operating under the 5 February 2004 W3C Patent Policy public list of any patent disclosures Essential Claim(s) section 6 of the W3C Patent Policy Table of Contents Abstract Status of This Document 1. Introduction Excluded from Scope Document Overview Document Conventions 2. Key Terms Accessibility Services of Platform Software Content (on and off the Web) Document Set of Documents Set of Software Programs Software User Agent 3. Closed Functionality 4. Text / Command-line / Terminal Applications and Interfaces 5. Comments on Conformance 6. Comments by Guideline and Success Criterion Principle 1: Perceivable Guideline 1.1: Text Alternatives Success Criterion 1.1.1: Non-text Content (Level A) Guideline 1.2: Time-based Media Success Criterion 1.2.1: Audio-only and Video-only (Prerecorded) (Level A) Success Criterion 1.2.2: Captions (Prerecorded) (Level A) Success Criterion 1.2.3: Audio Description or Media Alternative (Prerecorded) (Level A) Success Criterion 1.2.4: Captions (Live) (Level AA) Success Criterion 1.2.5: Audio Description (Prerecorded) (Level AA) Guideline 1.3: Adaptable Success Criterion 1.3.1: Info and Relationships (Level A) Success Criterion 1.3.2: Meaningful Sequence (Level A) Success Criterion 1.3.3: Sensory Characteristics (Level A) Guideline 1.4: Distinguishable Success Criterion 1.4.1: Use of Color (Level A) Success Criterion 1.4.2: Audio Control (Level A) Success Criterion 1.4.3: Contrast (Minimum) (Level AA) Success Criterion 1.4.4: Resize text (Level AA) Success Criterion 1.4.5: Images of Text (Level AA) Principle 2: Operable Guideline 2.1: Keyboard Accessible Success Criterion 2.1.1: Keyboard (Level A) Success Criterion 2.1.2: No Keyboard Trap (Level A) Guideline 2.2: Enough Time Success Criterion 2.2.1: Timing Adjustable (Level A) Success Criterion 2.2.2: Pause, Stop, Hide (Level A) Guideline 2.3: Seizures Success Criterion 2.3.1: Three Flashes or Below Threshold (Level A) Guideline 2.4: Navigable Success Criterion 2.4.1: Bypass Blocks (Level A) Success Criterion 2.4.2: Page Titled (Level A) Success Criterion 2.4.3: Focus Order (Level A) Success Criterion 2.4.4: Link Purpose (In Context) (Level A) Success Criterion 2.4.5: Multiple Ways (Level AA) Success Criterion 2.4.6: Headings and Labels (Level AA) Success Criterion 2.4.7: Focus Visible (Level AA) Principle 3: Understandable Guideline 3.1: Readable Success Criterion 3.1.1: Language of Page (Level A) Success Criterion 3.1.2: Language of Parts (Level AA) Guideline 3.2: Predictable Success Criterion 3.2.1: On Focus (Level A) Success Criterion 3.2.2: On Input (Level A) Success Criterion 3.2.3: Consistent Navigation (Level AA) Success Criterion 3.2.4: Consistent Identification (Level AA) Guideline 3.3: Input Assistance Success Criterion 3.3.1: Error Identification (Level A) Success Criterion 3.3.2: Labels or Instructions (Level A) Success Criterion 3.3.3: Error Suggestion (Level AA) Success Criterion 3.3.4: Error Prevention (Legal, Financial, Data) (Level AA) Principle 4: Robust Guideline 4.1: Compatible Success Criterion 4.1.1: Parsing (Level A) Success Criterion 4.1.2: Name, Role, Value (Level A) 7. Comments on Definitions in WCAG 2.0 Glossary in Appendix A Glossary Items that Apply to All Technologies Glossary Items Used only in AAA Success Criteria Glossary Items with Specific Guidance accessibility supported ambiguous to users in general assistive technology (as used in this document) changes of context conformance conforming alternate version content (Web content) contrast ratio general flash and red flash thresholds input error keyboard interface label name process programmatically determined programmatically set relative luminance role same functionality satisfies a success criterion set of Web pages structure technology user agent user interface component viewport Web page Appendix A. Success Criteria Problematic for Closed Functionality Appendix B. Background on Text / Command-line / Terminal Applications and Interfaces How text interfaces are realized How text applications have been made accessible via assistive technology Applying WCAG 2.0 to text applications Appendix C. Acknowledgements Participants in the WCAG2ICT Task Force Participants in the WCAG Working Group Enabling funders Appendix D. References 1. This document provides informative guidance (guidance that is not normative, and that does not set requirements) with regard to the interpretation and application of Web Content Accessibility Guidelines (WCAG) 2.0 WCAG20 Working Group Note This document is intended to help clarify how to use WCAG 2.0 to make non-web documents and software more accessible to people with disabilities. Addressing accessibility involves addressing the needs of people with auditory, cognitive, neurological, physical, speech, and visual disabilities, and the needs of people with accessibility requirements due to the effects of aging. Although this document covers a wide range of issues, it is not able to address all the needs of all people with disabilities. Because WCAG 2.0 was developed for the Web, addressing accessibility for non-web documents and software may involve provisions beyond those included in this document. Authors and developers are encouraged to seek relevant advice about current best practices to ensure that non-web documents and software are accessible, as far as possible, to people with disabilities. While WCAG 2.0 was designed to be technology-neutral, it assumes the presence of a “user agent” such as a browser, media player, or assistive technology as a means to access web content. Therefore, the application of WCAG 2.0 to documents and software in non-web contexts required some interpretation in order to determine how the intent of each WCAG 2.0 success criterion could be met in these different contexts of use. The bulk of the Task Force's work therefore involved evaluating how each WCAG 2.0 success criterion would apply in the context of non-web ICT, if it were applied to non-web ICT. The Task Force found that the majority of success criteria from WCAG 2.0 can apply to non-web documents and software with no or only minimal changes. Specifically, of the thirty-eight Level A and AA success criteria, twenty-six did not include any web related terms and apply directly as written and as described in the “Intent” sections from the updated Understanding WCAG 2.0 UNDERSTANDING-WCAG20 Of the remaining twelve success criteria, the Task Force found that eight of them apply as written when replacing certain Web-specific terms or phrases like “web page(s)” with non-web terms or phrases like “non-web document(s) and software” or “for non-web documents and software that use markup languages, in such a way that…” etc. Additional notes were also provided to assist in the application of these. The remaining four success criteria apply in situations when “a set of web pages”, or “multiple web pages” share some characteristic or behavior. In WCAG 2.0 the “unit of conformance” is the web page. While WCAG2ICT is not a standard, and thus conformance does not apply, it is still useful to look at what a “unit of evaluation” would be for non-web ICT. For non-web documents, WCAG2ICT uses a single document as the “unit of evaluation”, as it is the best analog to a web page. This became the basis for the notion of a “ set of documents set of software programs The 83 glossary terms were also reviewed. 51 applied to non-Web documents and software as written. Another 28 applied with additional notes or edits (largely related to phrases like “Web page(s)”), and the remaining 4 terms were only used in Level AAA success criteria which are not addressed by this Note. 1.1. The following are out of scope for this document: This document does not seek to determine which WCAG 2.0 provisions (principles, guidelines, or success criteria) should or should not apply to non-web ICT, but rather how they would apply, if applied. This document does not propose changes to WCAG 2.0 itself, nor its supporting documents; and does not include interpretations for implementing WCAG 2.0 in web technologies. During the development of this document, the WCAG2ICT Task Force did seek clarification on the intent of a number of the success criteria, which led to clarifications that are being made to the Understanding WCAG 2.0 document. Because this document deals with applying WCAG, which is a standard for web content accessibility, to ICT it does not deal with such things as closed products and requirements for non-user interface aspects of platforms, nor individual components. As such, this document is not sufficient by itself to ensure accessibility in non-web documents and software. This document does not comment on hardware aspects of products, non-user interface aspects of platforms, or user-interface components as individual items, because the basic constructs on which WCAG 2.0 is built do not apply to these. This document does not provide supporting techniques for implementing WCAG 2.0 in non-web documents and software. As this document is purely an informative Note about non-web ICT, and not a standard, it doesn't describe how non-web ICT should conform to it. 1.2. This document includes excerpted text from WCAG 2.0 principles, guidelines, and success criteria, as quoted from WCAG 2.0 without any changes. It also includes excerpted text from the “Intent” sections of the WCAG 2.0 supporting document Understanding WCAG 2.0 (Public Review Draft) UNDERSTANDING-WCAG20 Additional supporting documents for WCAG 2.0, such as the WCAG 2.0 Overview Techniques for WCAG 2.0 WCAG20-TECHS How to Meet WCAG 2.0: A customizable quick reference 1.3. The following stylistic conventions are used in this document: Quotes from WCAG 2.0 and Understanding WCAG 2.0 are in <blockquote> elements and visually styled as pale yellow inset boxes in slightly smaller text. They are prefaced by a reference to the original source such as “From {reference title} in {document}”. Additional guidance provided by this document begins with the phrase “Additional guidance” and is visually styled in pale blue boxes labeled by a heading having a dark blue background. Quotes from WCAG 2.0 begin with “From” and the success criterion number and name, and are presented as modified by the advice in this document with the modifications in <ins> elements visually styled as bold red text with dotted underlines. Notes are slightly inset and begin with the phrase “Note:”. If there are multiple notes for a specific item, they are numbered, e.g., “Note 1:”, etc. References to glossary items from WCAG 2.0 are presented in <cite> elements visually styled as ordinary text with a dotted underline, and contain title attributes noting these are WCAG definitions. They turn blue with a yellow background when mouse or keyboard focus is placed over them. References to glossary items in this document are presented in <cite> elements visually styled as ordinary text with a dashed underline, and contain title attributes noting these are Task Force definitions. They turn green with a yellow background when mouse or keyboard focus is placed over them. Note that some terms defined in WCAG 2.0 are redefined in WCAG2ICT and links are updated accordingly (except in direct quotes). Hereafter, the short title “WCAG2ICT” is used to reference this document. 2. Of the 83 glossary terms used in WCAG 2.0 there are two key glossary terms that need to be interpreted significantly differently when applied to non-web ICT. These are: “content” and “user agent”. Further, the glossary term “Web page” in WCAG 2.0 is replaced with newly defined terms “document” and “software”, and both “set of web pages” and “multiple web pages” are replaced with the newly defined terms “set of documents” and “set of software programs”. Finally, as part of addressing the fact that non-Web software doesn't leverage the WCAG 2.0 notion of a user agent, we introduce the new term “accessibility services of platform software”. The remaining 79 glossary terms from WCAG 2.0 are addressed in Chapter 7 Comments on Definitions in WCAG 2.0 Glossary in Appendix A 2.1. The term accessibility services of platform software accessibility services of platform software (as used in WCAG2ICT) services provided by an operating system, user agent, or other platform software that enable non-web documents or software to expose information about the user interface and events to assistive technologies and accessibility features of software Note: 2.2. WCAG 2.0 defines CONTENT as: content (web content) information and sensory experience to be communicated to the user by means of a user agent structure presentation For non-web content it is necessary to view this a bit more broadly. Within WCAG2ICT, the term “content” is used as follows: content (non-web content) (as used in WCAG2ICT) information and sensory experience to be communicated to the user by means of software structure presentation Note: Within WCAG2ICT wherever “content” or “web content” appears in a success criterion or Intent it should be replaced with “content” using the definition above. 2.3. The term document document (as used in WCAG2ICT) assembly of content Note 1: content Note 2: Note 3: software content Note 4: Note 5: content software Note 6: content Example: Counterexample: 2.4. The term set of documents set of documents (non-web) (as used in WCAG2ICT) group of documents Note 1: Note 2: One example of a set of documents would be a three-part report where each part is a separate file. At the beginning of each file the table of contents for “navigating” to the other parts is repeated. 2.5. The term set of software programs set of software programs (as used in WCAG2ICT) group of software Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7 Note 8: Example: Counterexamples: not A suite of programs for authoring different types of documents (text, spreadsheets, presentations, etc.) where the programs don't provide an explicit, consistent means to launch, or switch to, each of the other programs in the group. An office package consisting of multiple programs that launches as a single program that provides multiple functionalities such as writing, spreadsheet, etc., but the only way to navigate between programs is to open a document in one of the programs. A bundle of software programs that is sold together but the only way to navigate between the programs in the bundle is to use a platform software level menu to navigate between them (and not via a menu provided by each program that allows you to navigate to just the other programs in this bundle). A group of programs that was a set, but the programs have been moved to separate locations so that their “set” behaviors were disrupted and no longer work. Even though they were are 2.6. The term software software (as used in WCAG2ICT) software products or software aspects of hardware-software products that have a user interface and do not require a separate user agent to present any of its content Note 1. content Note 2. Note 3 content 2.7. WCAG 2.0 defines user agent as follows: user agent any software that retrieves and presents Web content for users Example: Web browsers, media players, plug-ins, and other programs—including assistive technologies For non-web ICT, “user agent” needs to be viewed differently. In WCAG 2.0, the term “user agent” only refers to retrieval and display of web content. For non-web ICT, the term “user agent” refers to retrieval and display of separate content that is not on the Web user agent (as used in WCAG2ICT) any software Note 1. content Note 2. Note 3: content 3. As noted in the Introduction, WCAG 2.0 assumes the presence of a “user agent” such as a browser, media player, or assistive technology as a means to access web content. Furthermore, many of the success criteria in WCAG 2.0 assume web content will be accessed by ICT that has assistive technologies connected to it, where the assistive technologies present the web content to the people with disabilities in accessible form. ICT products with “closed functionality” do not allow the use of some assistive technologies for all of their functions. In many cases such ICT products also lack a “user agent” or their equivalent. As a result, ICT following these success criteria by themselves will not make information accessible on ICT with closed functionality. Something else needs to be provided or be required in order to make the information addressed in these success criteria accessible. It is outside the task force work statement Because closed functionality, by definition, does not allow a user to attach assistive technology, WCAG success criteria that assume the presence of assistive technology will not facilitate accessibility as WCAG 2.0 intends. Where assistive technologies cannot be used, other output and input solutions are needed to achieve the intent of these success criteria. Examples of products with closed functionality include: an ebook or ebook reader program that allows assistive technologies to access all of the user interface controls of the ebook program (open functionality) but does not allow the assistive technologies to access the actual content of book (closed functionality). an operating system that requires the user to provide log in credentials before it allows any assistive technologies to be loaded. The log-in portion would be closed functionality. a travel kiosk that provides an audio interface for blind and vision-impaired users as a built-in alternative to the visual interface and tactile keys as an alternative to touch screen operation for both blind users and those who can't operate a touch screen. See Appendix A: Success Criteria Problematic for Closed Functionality 4. Text applications are a class of software ICT that appeared decades ago, prior to the emergence of the graphical user interface (GUI) and the Web. The interface of a text application is generated using only text characters, and either a hardware terminal or a software terminal application handles the rendering of the text application—similar to how a web user agent handles the rendering of a web application. Text applications only accept text input (though some terminal applications which render text applications in the GUI may utilize a mouse or other input devices). Command-line applications are a subset of text applications with further specific properties. Historically, assistive technologies developed alongside text applications, and several of these use a variety of analysis and scripting techniques to make text applications accessible. Although there are far fewer new text applications being developed compared to new GUI or web applications, text applications remain in use today, and both text applications and the assistive technologies designed for text applications are in active development. Though this class of applications predates the Web, WCAG can be applied to them. As noted in Appendix B. Background on Text / Command-line / Terminal Applications and Interfaces 5. WCAG2ICT is not a standard, so it is not possible to conform to WCAG2ICT. However, some entities may wish to use the information in WCAG2ICT to help establish standards or regulations regarding accessibility in ICT that are based on WCAG 2.0. While such standards or regulations will need to address matters of conformance themselves, the following notes may be of assistance to those wishing to draft their own requirements: The WCAG 2.0 success criteria and the conformance requirements were designed to work together, such that the language of the success criteria is based on the nature of the conformance requirements. The choice of what level to use for a given criteria (A vs. AA vs. AAA) was further influenced by a number of factors specific to the web domain, as set forth in Understanding Levels of Compliance In the WCAG 2.0 conformance model, a success criteria is satisfied if the item being evaluated does not fail it. If the success criterion is in relation to something that does not exist for the item being evaluated (e.g. a success criterion is about captioning audio and there is no audio) then the success criterion is automatically met. This approach is central to the way the success criteria in WCAG are structured and worded. WCAG 2.0 conformance is applied to the item being evaluated (i.e. web page) as a whole, except when a process includes use of several items, in which case all of the items that are needed in order to complete the process must conform. In WCAG 2.0, when conformance relies on accessibility features of the platform (i.e. browser for web content) or on assistive technologies, WCAG 2.0 requires that there are assistive technologies, etc. that work with the product (web page). That is, conformance with WCAG 2.0 requires that the approaches used are supported by assistive technologies. WCAG 2.0 allows information on part of a page to not conform if the same information is available elsewhere on the page in conforming fashion. However WCAG 2.0 identifies 4 success criteria that must be met on all areas of the page because they can interfere with the user's ability to access and use other parts of the page: 1.4.2 Audio Control 2.1.2 No Keyboard Trap 2.2.2 Pause, Stop, Hide 2.3.1 Three Flashes or Below Threshold Also, as noted in the Introduction, it wasn't possible to unambiguously carve up software into discrete pieces, and so the unit of evaluation for non-web software is the whole software program. As with any software testing this can be a very large unit of evaluation, and methods similar to standard software testing might be used. 6. The sections that follow are organized according to the principles, guidelines, and success criteria from WCAG 2.0. The text of each item from WCAG 2.0 is copied as quoted text. Following that, the WCAG2ICT guidance is provided. Finally, the “Intent” from Understanding WCAG 2.0 is copied as quoted text; the Task Force makes no substitutions or edits in this text. In visual presentations, the WCAG2ICT guidance is set out in a box with a blue bar to the left, to highlight that this is the content specific to this document. Principle 1: Perceivable From Principle 1 Information and user interface components must be presentable to users in ways they can perceive. Additional Guidance When Applying Principle 1 to Non-Web Documents and Software: In WCAG 2.0, the Principles are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Principle 1 applies directly as written. Guideline 1.1: Text Alternatives From Guideline 1.1 Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language. Additional Guidance When Applying Guideline 1.1 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 1.1 applies directly as written. Intent from Understanding Guideline 1.1 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 1.1 The purpose of this guideline is to ensure that all non-text content is also available in text Note: Success Criterion 1.1.1: Non-text Content (Level A) From Success Criterion 1.1.1 All non-text content text alternative Controls, Input: name Guideline 4.1 Time-Based Media: Guideline 1.2 Test: text Sensory: specific sensory experience CAPTCHA Decoration, Formatting, Invisible: pure decoration assistive technology Additional Guidance When Applying Success Criterion 1.1.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.1.1 Note 1: Note 2: Closed Functionality Intent from Understanding Success Criterion 1.1.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.1.1 The intent of this Success Criterion is to make information conveyed by non-text content accessible through the use of a text alternative. Text alternatives are a primary way for making information accessible because they can be rendered through any sensory modality (for example, visual, auditory or tactile) to match the needs of the user. Providing text alternatives allows the information to be rendered in a variety of ways by a variety of user agents. For example, a person who cannot see a picture can have the text alternative read aloud using synthesized speech. A person who cannot hear an audio file can have the text alternative displayed so that he or she can read it. In the future, text alternatives will also allow information to be more easily translated into sign language or into a simpler form of the same language. Note on CAPTCHA CAPTCHAs Inaccessibility of CAPTCHA Because some users with disabilities will still not be able to access sites that meet the minimum requirements, the Working Group provides recommendations for additional steps. Organizations motivated to conform to WCAG should be aware of the importance of this topic and should go as far beyond the minimum requirements of the guidelines as possible. Additional recommended steps include: Providing more than two modalities of CAPTCHAs Providing access to a human customer service representative who can bypass CAPTCHA Not requiring CAPTCHAs for authorized users Additional information Non-text content can take a number of forms, and this Success Criterion specifies how each is to be handled. For non-text content that is not covered by one of the other situations listed below, prerecorded audio-only prerecorded video-only Live-audio-only Live-video-only For non-text content that is a control or accepts user input Non-text content that is time-based media 1.2 For Live Audio-only and live video-only content Sometimes a test or exercise must be partially or completely presented in non-text format. Sometimes content is primarily intended to create a specific sensory experience Sometimes there are non-text exercises that are used to prove you are human. Sometimes there is non-text content that really is not meant to be seen or understood by the user. Specific Benefits of Success Criterion 1.1.1 This Success Criterion helps people who have difficulty perceiving visual content. Assistive technology can read text aloud, present it visually, or convert it to braille. Text alternatives may help some people who have difficulty understanding the meaning of photographs, drawings, and other images (e.g., line drawings, graphic designs, paintings, three-dimensional representations), graphs, charts, animations, etc. People who are deaf, are hard of hearing, or who are having trouble understanding audio information for any reason can read the text presentation. Research is ongoing regarding automatic translation of text into sign language. People who are deaf-blind can read the text in braille. Additionally, text alternatives support the ability to search for non-text content and to repurpose content in a variety of ways. Guideline 1.2: Time-based Media From Guideline 1.2 Provide alternatives for time-based media. Additional Guidance When Applying Guideline 1.2 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 1.2 applies directly as written. Intent from Understanding Guideline 1.2 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 1.2 The purpose of this guideline is to provide access to time-based and synchronized media.This includes media that is: audio-only video-only audio-video audio and/or video combined with interaction To make it easy for authors to quickly determine which success criteria apply to their content, the type of media each success criterion applies to is included in its short name. For audio-only video-only audio-only video-only audio-only video-only Media can also be live prerecorded live prerecorded Synchronized media synchronized media audio video media alternative for text Note that an audio file accompanied by interaction is covered here, as is a video-only file that involves interaction. These are covered because interaction must take place at a particular time. Having a text transcript that said, "for more information, click now," would not be very helpful since the reader would have no idea when the audio said, "now." As a result, synchronized captions would be needed. Sometimes, there is so much dialogue that audio description cannot fit into existing pauses in the dialogue. The option at Level A to provide an alternative for time-based media instead of audio description for synchronized media would allow access to all of the information in the synchronized media. This option also allows access to the visual information in non-visual form when audio description is not provided for some other reason. For synchronized media that includes interaction, interactive elements (for example links) could be embedded in the alternative for time-based media. This guideline also includes (at Level AAA) sign language interpretation for synchronized media as well as an approach called extended audio description. In extended audio description, the video is frozen periodically to allow more audio description to take place than is possible in the existing pauses in the dialogue. This is a case where higher-level Success Criteria build upon the requirements of lower-level Success Criterion with the intention of having cumulative, progressively stronger, requirements. Success Criterion 1.2.1: Audio-only and Video-only (Prerecorded) (Level A) From Success Criterion 1.2.1 For prerecorded audio-only video-only media alternative for text Prerecorded Audio-only: alternative for time-based media Prerecorded Video-only: Additional Guidance When Applying Success Criterion 1.2.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.2.1 Note 1: non-web document software Note 2: Closed Functionality Intent from Understanding Success Criterion 1.2.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.2.1 The intent of this Success Criterion is to make information conveyed by prerecorded audio-only and prerecorded video-only content available to all users. Alternatives for time-based media that are text based make information accessible because text can be rendered through any sensory modality (for example, visual, auditory or tactile) to match the needs of the user. In the future, text could also be translated into symbols, sign language or simpler forms of the language (future). An example of pre-recorded video with no audio information or user interaction is a silent movie. The purpose of the transcript is to provide an equivalent to what is presented visually. For prerecorded video content, authors have the option to provide an audio track. The purpose of the audio alternative is to be an equivalent to the video. This makes it possible for users with and without vision impairment to review content simultaneously. The approach can also make it easier for those with cognitive, language and learning disabilities to understand the content because it would provide parallel presentation. Note: See also Understanding Success Criterion 1.2.9 Audio-only (Live) Specific Benefits of Success Criterion 1.2.1 This Success Criterion helps people who have difficulty perceiving visual content. Assistive technology can read text alternatives aloud, present them visually, or convert them to braille. Alternatives for timed-based media that are text based may help some people who have difficulty understanding the meaning of prerecorded video content. People who are deaf, are hard of hearing, or who are having trouble understanding audio information for any reason can read the text presentation. Research is ongoing regarding automatic translation of text into sign language. People who are deaf-blind can read the text in braille. Additionally, text supports the ability to search for non-text content and to repurpose content in a variety of ways. Success Criterion 1.2.2: Captions (Prerecorded) (Level A) From Success Criterion 1.2.2 Captions prerecorded audio synchronized media media alternative for text Additional Guidance When Applying Success Criterion 1.2.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.2.2 Note: captions content Intent from Understanding Success Criterion 1.2.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.2.2 The intent of this Success Criterion is to enable people who are deaf or hard of hearing to watch synchronized media presentations. Captions provide the part of the content available via the audio track. Captions not only include dialogue, but identify who is speaking and include non-speech information conveyed through sound, including meaningful sound effects. It is acknowledged that at the present time there may be difficulty in creating captions for time-sensitive material and this may result in the author being faced with the choice of delaying the information until captions are available, or publishing time-sensitive content that is inaccessible to the deaf, at least for the interval until captions are available. Over time, the tools for captioning as well as building the captioning into the delivery process can shorten or eliminate such delays. Captions are not needed when the synchronized media is, itself, an alternate presentation of information that is also presented via text on the Web page. For example, if information on a page is accompanied by a synchronized media presentation that presents no more information than is already presented in text, but is easier for people with cognitive, language, or learning disabilities to understand, then it would not need to be captioned since the information is already presented on the page in text or in text alternatives (e.g., for images). See also Understanding Success Criterion 1.2.4 Captions (Live) Specific Benefits of Success Criterion 1.2.2 People who are deaf or have a hearing loss can access the auditory information in the synchronized media content through captions. Success Criterion 1.2.3: Audio Description or Media Alternative (Prerecorded) (Level A) From Success Criterion 1.2.3 An alternative for time-based media audio description prerecorded video synchronized media media alternative for text Additional Guidance When Applying Success Criterion 1.2.3 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.2.3 Note 1: audio description Note 2: Note 3: Closed Functionality Intent from Understanding Success Criterion 1.2.3 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.2.3 The intent of this Success Criterion is to provide people who are blind or visually impaired access to the visual information in a synchronized media presentation. This Success Criterion describes two approaches, either of which can be used. One approach is to provide audio description of the video content. The audio description augments the audio portion of the presentation with the information needed when the video portion is not available. During existing pauses in dialogue, audio description provides information about actions, characters, scene changes, and on-screen text that are important and are not described or spoken in the main sound track. The second approach involves providing all of the information in the synchronized media (both visual and auditory) in text form. An alternative for time-based media provides a running description of all that is going on in the synchronized media content. The alternative for time-based media reads something like a screenplay or book. Unlike audio description, the description of the video portion is not constrained to just the pauses in the existing dialogue. Full descriptions are provided of all visual information, including visual context, actions and expressions of actors, and any other visual material. In addition, non-speech sounds (laughter, off-screen voices, etc.) are described, and transcripts of all dialogue are included. The sequence of description and dialogue transcripts are the same as the sequence in the synchronized media itself. As a result, the alternative for time-based media can provide a much more complete representation of the synchronized media content than audio description alone. If there is any interaction as part of the synchronized media presentation (e.g., "press now to answer the question") then the alternative for time-based media would provide hyperlinks or whatever is needed to provide the same functionality. Note 1: Note 2: See also Understanding Success Criterion 1.2.5 Audio Description (Prerecorded) Understanding Success Criterion 1.2.7 Extended Audio Description (Prerecorded) Understanding Success Criterion 1.2.8 Media Alternative (Prerecorded) Specific Benefits of Success Criterion 1.2.3 This Success Criterion may help some people who have difficulty watching video or other synchronized media content, including people who have difficulty perceiving or understanding moving images. Success Criterion 1.2.4: Captions (Live) (Level AA) From Success Criterion 1.2.4 Captions live audio synchronized media Additional Guidance When Applying Success Criterion 1.2.4 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.2.4 Note: captions content Intent from Understanding Success Criterion 1.2.4 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.2.4 The intent of this Success Criterion is to enable people who are deaf or hard of hearing to watch real-time This success criterion was intended to apply to broadcast of synchronized media and is not intended to require that two-way multimedia calls between two or more individuals through web apps must be captioned regardless of the needs of users. Responsibility for providing captions would fall to the content providers (the callers) or the “host” caller, and not the application. Specific Benefits of Success Criterion 1.2.4 People who are deaf or have a hearing loss can access the auditory information in the synchronized media content through captions. Success Criterion 1.2.5: Audio Description (Prerecorded) (Level AA) From Success Criterion 1.2.5 Audio description prerecorded video synchronized media Additional Guidance When Applying Success Criterion 1.2.5 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.2.5 Note1: audio description Note2: Intent from Understanding Success Criterion 1.2.5 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.2.5 The intent of this Success Criterion is to provide people who are blind or visually impaired access to the visual information in a synchronized media presentation. The audio description augments the audio portion of the presentation with the information needed when the video portion is not available. During existing pauses in dialogue, audio description provides information about actions, characters, scene changes, and on-screen text that are important and are not described or spoken in the main sound track. Note 1: Note 2: Specific Benefits of Success Criterion 1.2.5 People who are blind or have low vision as well as those with cognitive limitations who have difficulty interpreting visually what is happening benefit from audio description of visual information. Guideline 1.3: Adaptable From Guideline 1.3 Create content that can be presented in different ways (for example simpler layout) without losing information or structure. Additional Guidance When Applying Guideline 1.3 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 1.3 applies directly as written. Intent from Understanding Guideline 1.3 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 1.3 The purpose of this guideline is to ensure that all information is available in a form that can be perceived by all users, for example, spoken aloud, or presented in a simpler visual layout. If all of the information is available in a form that can be determined by software, then it can be presented to users in different ways (visually, audibly, tactilely etc.). If information is embedded in a particular presentation in such a way that the structure and information cannot be programmatically determined by the assistive technology, then it cannot be rendered in other formats as needed by the user. The Success Criteria under this guideline all seek to ensure that different types of information that are often encoded in presentation are also available so that they can be presented in other modalities. structure: presentation: Success Criterion 1.3.1: Info and Relationships (Level A) From Success Criterion 1.3.1 Information, structure relationships presentation programmatically determined Additional Guidance When Applying Success Criterion 1.3.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.3.1 Note 1: accessibility services provided by platform software Note 2: Closed Functionality Intent from Understanding Success Criterion 1.3.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.3.1 The intent of this Success Criterion is to ensure that information and relationships that are implied by visual or auditory formatting are preserved when the presentation format changes. For example, the presentation format changes when the content is read by a screen reader or when a user style sheet is substituted for the style sheet provided by the author. Sighted users perceive structure and relationships ; items that share a common characteristic are organized into a table where the relationship of cells sharing the same row or column and the relationship of each cell to its row and/or column header are necessary for understanding; Having these structures and these relationships programmatically determined or available in text ensures that information important for comprehension will be perceivable to all. Auditory cues may be used as well. For example, a chime might indicate the beginning of a new section; a change in voice pitch or speech rate may be used to emphasize important information or to indicate quoted text; etc. When such relationships are perceivable to one set of users, those relationships can be made to be perceivable to all. One method of determining whether or not information has been properly provided to all users is to access the information serially in different modalities. If links to glossary items are implemented using anchor elements (or the proper link element for the technology in use) and identified using a different font face, a screen reader user will hear that the item is a link when the glossary term is encountered even though they may not receive information about the change in font face. An on-line catalog may indicate prices using a larger font colored red. A screen reader or person who cannot perceive red, still has the information about the price as long as it is preceded by the currency symbol. Some technologies do not provide a means to programmatically determine some types of information and relationships. In that case then there should be a text description of the information and relationships. For instance, "all required fields are marked with an asterisk (*)". The text description should be near the information it is describing (when the page is linearized), such as in the parent element or in the adjacent element. There may also be cases where it may be a judgment call as to whether the relationships should be programmatically determined or be presented in text. However, when technologies support programmatic relationships, it is strongly encouraged that information and relationships be programmatically determined rather than described in text. Note: Success Criterion 1.4.1 Specific Benefits of Success Criterion 1.3.1 This Success Criterion helps people with different disabilities by allowing user agents to adapt content according to the needs of individual users. Users who are blind (using a screen reader) benefit when information conveyed through color is also available in text (including text alternatives for images that use color to convey information). Users who are deaf-blind using braille (text) refreshable displays may be unable to access color-dependent information. Success Criterion 1.3.2: Meaningful Sequence (Level A) From Success Criterion 1.3.2 When the sequence in which content is presented affects its meaning, a correct reading sequence programmatically determined Additional Guidance When Applying Success Criterion 1.3.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.3.2 Note: Closed Functionality Intent from Understanding Success Criterion 1.3.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.3.2 The intent of this Success Criterion is to enable a user agent to provide an alternative presentation of content while preserving the reading order needed to understand the meaning. It is important that it be possible to programmatically determine at least one sequence of the content that makes sense. Content that does not meet this Success Criterion may confuse or disorient users when assistive technology reads the content in the wrong order, or when alternate style sheets or other formatting changes are applied. A sequence is meaningful The semantics of some elements define whether or not their content is a meaningful sequence. For instance, in HTML, text is always a meaningful sequence. Tables and ordered lists are meaningful sequences, but unordered lists are not. The order of content in a sequence is not always meaningful. For example, the relative order of the main section of a Web page and a navigation section does not affect their meaning. They could occur in either order in the programmatically determined reading sequence. As another example, a magazine article contains several callout sidebars. The order of the article and the sidebars does not affect their meaning. In these cases there are a number of different reading orders for a Web page that can satisfy the Success Criterion. For clarity: Providing a particular linear order is only required where it affects meaning. There may be more than one order that is "correct" (according to the WCAG 2.0 definition). Only one correct order needs to be provided. Specific Benefits of Success Criterion 1.3.2 This Success Criterion may help people who rely on assistive technologies that read content aloud. The meaning evident in the sequencing of the information in the default presentation will be the same when the content is presented in spoken form. Success Criterion 1.3.3: Sensory Characteristics (Level A) From Success Criterion 1.3.3 Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, size, visual location, orientation, or sound. Note: Guideline 1.4 Additional Guidance When Applying Success Criterion 1.3.3 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.3.3 Intent from Understanding Success Criterion 1.3.3 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.3.3 The intent of this Success Criterion is to ensure that all users can access instructions for using the content, even when they cannot perceive shape or size or use information about spatial location or orientation. Some content relies on knowledge of the shape or position of objects that are not available from the structure of the content (for example, "round button" or "button to the right"). Some users with disabilities are not able to perceive shape or position due to the nature of the assistive technologies they use. This Success Criterion requires that additional information be provided to clarify anything that is dependent on this kind of information. Providing information using shape and/or location, however, is an effective method for many users including those with cognitive limitations. This provision should not discourage those types of cues as long as the information is also provided in other ways. In some languages, it is commonly understood that "above" refers to the content previous to that point in the content and "below" refers to the content after that point. In such languages, if the content being referenced is in the appropriate place in the reading order and the references are unambiguous, statements such as "choose one of the links below" or "all of the above" would conform to this Success Criterion. WCAG was designed to apply only to controls that were displayed on a web page. The intent was to avoid describing controls solely via references to visual or auditory cues. When applying this to instructions for operating physical hardware controls (e.g. a web kiosk with dedicated content), tactile cues on the hardware might be described (e.g. the arrow shaped key, the round key on the right side). This success criterion is not intended to prevent the use of tactile cues in instructions. Specific Benefits of Success Criterion 1.3.3 People who are blind and people who have low vision may not be able to understand information if it is conveyed by shape and/or location. Providing additional information other than shape and/or location will allow them to understand the information conveyed by shape and/or alone. Guideline 1.4: Distinguishable From Guideline 1.4 Make it easier for users to see and hear content including separating foreground from background. Additional Guidance When Applying Guideline 1.4 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 1.4 applies directly as written. Intent from Understanding Guideline 1.4 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 1.4 While some guidelines are focused on making information available in a form that can be presented in alternate formats, this guideline is concerned with making the default presentation as easy to perceive as possible to people with disabilities. The primary focus is on making it easier for users to separate foreground information from the background. For visual presentations this involves making sure that information presented on top of a background contrasts sufficiently with the background. For audio presentations this involves making sure that foreground sounds are sufficiently louder than the background sounds. Individuals with visual and hearing disabilities have much greater difficulty separating foreground and background information. Success Criterion 1.4.1: Use of Color (Level A) From Success Criterion 1.4.1 Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. Note: Guideline 1.3 Additional Guidance When Applying Success Criterion 1.4.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.4.1 Intent from Understanding Success Criterion 1.4.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.4.1 The intent of this Success Criterion is to ensure that all users can access information that is conveyed by color differences, that is, by the use of color where each color has a meaning assigned to it. If the information is conveyed through color differences in an image (or other non-text format), the color may not be seen by users with color deficiencies. In this case, providing the information conveyed with color through another visual means ensures users who cannot see color can still perceive the information. Color is an important asset in design of Web content, enhancing its aesthetic appeal, its usability, and its accessibility. However, some users have difficulty perceiving color. People with partial sight often experience limited color vision, and many older users do not see color well. In addition, people using text-only, limited-color or monochrome displays and browsers will be unable to access information that is presented only in color. Examples of information conveyed by color differences: “required fields are red", “error is shown in red", and “Mary's sales are in red, Tom's are in blue". Examples of indications of an action include: using color to indicate that a link will open in a new window or that a database entry has been updated successfully. An example of prompting a response would be: using highlighting on form fields to indicate that a required field had been left blank. Note: Specific Benefits of Success Criterion 1.4.1 Users with partial sight often experience limited color vision. Some older users may not be able to see color well. Users who have color-blindness benefit when information conveyed by color is available in other visual ways. People using text-only, limited color, or monochrome displays may be unable to access color-dependent information. Users who have problems distinguishing between colors can look or listen for text cues. People using Braille displays or other tactile interfaces can detect text cues by touch. Success Criterion 1.4.2: Audio Control (Level A) From Success Criterion 1.4.2 If any audio on a Web page plays automatically for more than 3 seconds, either a mechanism Note: Conformance Requirement 5: Non-Interference Additional Guidance When Applying Success Criterion 1.4.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.4.2 With these substitutions, it would read: 1.4.2 Audio Control: in a non-web document software Note: part of a non-web document software whole document software content in the document software Intent from Understanding Success Criterion 1.4.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.4.2 Individuals who use screen reading software can find it hard to hear the speech output if there is other audio playing at the same time. This difficulty is exacerbated when the screen reader's speech output is software based (as most are today) and is controlled via the same volume control as the sound. Therefore, it is important that the user be able to turn off the background sound. Note: Having control of the volume includes being able to reduce its volume to zero. Note: started stopped See also Understanding Success Criterion 1.4.7 Low or No Background Audio Specific Benefits of Success Criterion 1.4.2 Individuals who use screen reading technologies can hear the screen reader without other sounds playing. This is especially important for those who are hard of hearing and for those whose screen readers use the system volume (so they cannot turn sound down and screen reader up). This Success Criterion also benefits people who have difficulty focusing on visual content (including text) when audio is playing. Success Criterion 1.4.3: Contrast (Minimum) (Level AA) From Success Criterion 1.4.3 The visual presentation of text images of text contrast ratio Large Text: Large-scale Incidental: user interface component pure decoration Logotypes: Additional Guidance When Applying Success Criterion 1.4.3 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.4.3 Intent from Understanding Success Criterion 1.4.3 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.4.3 The intent of this Success Criterion is to provide enough contrast between text and its background so that it can be read by people with moderately low vision (who do not use contrast-enhancing assistive technology). For people without color deficiencies, hue and saturation have minimal or no effect on legibility as assessed by reading performance (Knoblauch et al., 1991). Color deficiencies can affect luminance contrast somewhat. Therefore, in the recommendation, the contrast is calculated in such a way that color is not a key factor so that people who have a color vision deficit will also have adequate contrast between the text and the background. Text that is decorative and conveys no information is excluded. For example, if random words are used to create a background and the words could be rearranged or substituted without changing meaning, then it would be decorative and would not need to meet this criterion. Text that is larger and has wider character strokes is easier to read at lower contrast. The contrast requirement for larger text is therefore lower. This allows authors to use a wider range of color choices for large text, which is helpful for design of pages, particularly titles. 18 point text or 14 point bold text is judged to be large enough to require a lower contrast ratio. (See The American Printing House for the Blind Guidelines for Large Printing and The Library of Congress Guidelines for Large Print under Resources Note: e.g. The previously-mentioned contrast requirements for text also apply to images of text (text that has been rendered into pixels and then stored in an image format) as stated in Success Criterion 1.4.3. This requirement applies to situations in which images of text were intended to be understood as text. Incidental text, such as in photographs that happen to include a street sign, are not included. Nor is text that for some reason is designed to be invisible to all viewers. Stylized text, such as in corporate logos, should be treated in terms of its function on the page, which may or may not warrant including the content in the text alternative. Corporate visual guidelines beyond logo and logotype are not included in the exception. In this provision there is an exception that reads "that are part of a picture that contains significant other visual content,". This exception is intended to separate pictures that have text in them from images of text that are done to replace text in order to get a particular look. Note 1: Note 2: Although this Success Criterion only applies to text, similar issues occur for data presented in charts or graphs. Good color contrast should also be provided for data presented in these forms. See also Understanding Success Criterion 1.4.6 Contrast (Enhanced) Rationale for the Ratios Chosen A contrast ratio of 3:1 is the minimum level recommended by [ISO-9241-3] [ANSI-HFES-100-1988] The rationale is based on a) adoption of the 3:1 contrast ratio for minimum acceptable contrast for normal observers, in the ANSI standard, and b) the empirical finding that in the population, visual acuity of 20/40 is associated with a contrast sensitivity loss of roughly 1.5 [ARDITI-FAYE] Hues are perceived differently by users with color vision deficiencies (both congenital and acquired) resulting in different colors and relative luminance contrasts than for normally sighted users. Because of this, effective contrast and readability are different for this population. However, color deficiencies are so diverse that prescribing effective general use color pairs (for contrast) based on quantitative data is not feasible. Requiring good luminance contrast accommodates this by requiring contrast that is independent of color perception. Fortunately, most of the luminance contribution is from the mid and long wave receptors which largely overlap in their spectral responses. The result is that effective luminance contrast can generally be computed without regard to specific color deficiency, except for the use of predominantly long wavelength colors against darker colors (generally appearing black) for those who have protanopia. (We provide an advisory technique on avoiding red on black for that reason). For more information see [ARDITI-KNOBLAUCH] [ARDITI-KNOBLAUCH-1996] [ARDITI] The contrast ratio of 4.5:1 was chosen for level AA because it compensated for the loss in contrast sensitivity usually experienced by users with vision loss equivalent to approximately 20/40 vision. (20/40 calculates to approximately 4.5:1.) 20/40 is commonly reported as typical visual acuity of elders at roughly age 80. [GITTINGS-FOZARD] The contrast ratio of 7:1 was chosen for level AAA because it compensated for the loss in contrast sensitivity usually experienced by users with vision loss equivalent to approximately 20/80 vision. People with more than this degree of vision loss usually use assistive technologies to access their content (and the assistive technologies usually have contrast enhancing, as well as magnification capability built into them). The 7:1 level therefore generally provides compensation for the loss in contrast sensitivity experienced by users with low vision who do not use assistive technology and provides contrast enhancement for color deficiency as well. Note: [ISO-9241-3] [ANSI-HFES-100-1988] Notes on formula Conversion from nonlinear to linear RGB values is based on IEC/4WD 61966-2-1 [IEC-4WD] [sRGB] The formula (L1/L2) for contrast is based on [ISO-9241-3] [ANSI-HFES-100-1988] The ANSI/HFS 100-1988 standard calls for the contribution from ambient light to be included in the calculation of L1 and L2. The .05 value used is based on Typical Viewing Flare from [IEC-4WD] [sRGB] This Success Criterion and its definitions use the terms "contrast ratio" and "relative luminance" rather than "luminance" to reflect the fact that Web content does not emit light itself. The contrast ratio gives a measure of the relative luminance that would result when displayed. (Because it is a ratio, it is dimensionless.) Note 1: related resources Note 2: Understanding Success Criterion 2.4.7 Focus Visible Note 3: Understanding Success Criterion 1.4.5 Images of Text Specific Benefits of Success Criterion 1.4.3 People with low vision often have difficulty reading text that does not contrast with its background. This can be exacerbated if the person has a color vision deficiency that lowers the contrast even further. Providing a minimum luminance contrast ratio between the text and its background can make the text more readable even if the person does not see the full range of colors. It also works for the rare individuals who see no color. Success Criterion 1.4.4: Resize text (Level AA) From Success Criterion 1.4.4 Except for captions images of text text assistive technology Additional Guidance When Applying Success Criterion 1.4.4 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.4.4 Note 1: Content Note 2: assistive technologies content Note 3: Closed Functionality Intent from Understanding Success Criterion 1.4.4 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.4.4 The intent of this Success Criterion is to ensure that visually rendered text, including text-based controls (text characters that have been displayed so that they can be seen [vs. text characters that are still in data form such as ASCII]) can be scaled successfully so that it can be read directly by people with mild visual disabilities, without requiring the use of assistive technology such as a screen magnifier. Users may benefit from scaling all content on the Web page, but text is most critical. The scaling of content is primarily a user agent responsibility. User agents that satisfy UAAG 1.0 Checkpoint 4.1 The author cannot rely on the user agent to satisfy this Success Criterion for HTML content if users do not have access to a user agent with zoom support. For example, if they work in an environment that requires them to use IE 6. If the author is using a technology whose user agents do not provide zoom support, the author is responsible to provide this type of functionality directly or to provide content that works with the type of functionality provided by the user agent. If the user agent doesn't provide zoom functionality but does let the the user change the text size, the author is responsible for ensuring that the content remains usable when the text is resized. Some user interface components that function as a label and require activation by the user to access content are not wide enough to accommodate the label's content. For example, in Web mail applications the subject column may not be Content satisfies the Success Criterion if it can be scaled up to 200%, that is, up to twice the width and height. Authors may support scaling beyond that limit, however, as scaling becomes more extreme, adaptive layouts may introduce usability problems. For example, words may be too wide to fit into the horizontal space available to them, causing them to be truncated; layout constraints may cause text to overlap with other content when it is scaled larger; or only one word of a sentence may fit on each line, causing the sentence to be displayed as a vertical column of text that is difficult to read. The working group feels that 200% is a reasonable accommodation that can support a wide range of designs and layouts, and complements older screen magnifiers that provide a minimum magnification of 200%. Above 200%, zoom (which resizes text, images, and layout regions and creates a larger canvas that may require both horizontal and vertical scrolling) may be more effective than text resizing. Assistive technology dedicated to zoom support would usually be used in such a situation and may provide better accessibility than attempts by the author to support the user directly. Note: See also Understanding Success Criterion 1.4.8 Visual Presentation Specific Benefits of Success Criterion 1.4.4 This Success Criterion helps people with low vision by letting them increase text size in content so that they can read it. Success Criterion 1.4.5: Images of Text (Level AA) From Success Criterion 1.4.5 If the technologies being used can achieve the visual presentation, text images of text Customizable: visually customized Essential: essential Note: Additional Guidance When Applying Success Criterion 1.4.5 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 1.4.5 Note: Closed Functionality Intent from Understanding Success Criterion 1.4.5 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 1.4.5 The intent of this Success Criterion is to encourage authors, who are using technologies which are capable of achieving their desired default visual presentation, to enable people who require a particular visual presentation of text to be able to adjust the text presentation as needed. This includes people who require the text in a particular font size, foreground and background color, font family, line spacing or alignment. If an author can use text to achieve the same visual effect, he or she should present the information as text rather than using an image. If for any reason, the author cannot format the text to get the same effect, the effect won't be reliably presented on the commonly available user agents, or using a technology to meet this criterion would interfere with meeting other criteria Images of text can also be used where it is possible for users to customize the image of text to match their requirements. The definition of image of text contains the note: "Note: This does not include text that is part of a picture that contains significant other visual content." Examples of such pictures include graphs, screenshots, and diagrams which visually convey important information through more than just text. Techniques for satisfying this Success Criterion are the same as those for Success Criterion 1.4.9, except that they only need to apply if the visual presentation can be achieved with the technologies that the author is using. For Success Criterion 1.4.9, the sufficient techniques would be applied only when the user can customize the output. See also Understanding Success Criterion 1.4.9 Images of Text (No Exception) Specific Benefits of Success Criterion 1.4.5 People with low vision (who may have trouble reading the text with the authored font family, size and/or color). People with visual tracking problems (who may have trouble reading the text with the authored line spacing and/or alignment). People with cognitive disabilities that affect reading. Principle 2: Operable From Principle 2 User interface components and navigation must be operable. Additional Guidance When Applying Principle 2 to Non-Web Documents and Software: In WCAG 2.0, the Principles are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Principle 2 applies directly as written. Guideline 2.1: Keyboard Accessible From Guideline 2.1 Make all functionality available from a keyboard. Additional Guidance When Applying Guideline 2.1 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 2.1 applies directly as written. Intent from Understanding Guideline 2.1 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 2.1 If all functionality Note that providing universal keyboard input does not mean that other types of input should not be supported. Optimized speech input, optimized mouse/pointer input, etc., are also good. The key is to provide keyboard input and control as well. Some devices do not have native keyboards—for example, a PDA or cell phone. If these devices have a Web browsing capability, however, they will have some means of generating text or "keystrokes". This guideline uses the term " keyboard interface Success Criterion 2.1.1: Keyboard (Level A) From Success Criterion 2.1.1 All functionality keyboard interface Note 1: Note 2: Additional Guidance When Applying Success Criterion 2.1.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 2.1.1 Note 1: Note 2: Closed Functionality Intent from Understanding Success Criterion 2.1.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.1.1 The intent of this Success Criterion is to ensure that, wherever possible, content can be operated through a keyboard or keyboard interface (so an alternate keyboard can be used). When content can be operated through a keyboard or alternate keyboard, it is operable by people with no vision (who cannot use devices such as mice that require eye-hand coordination) as well as by people who must use alternate keyboards or input devices that act as keyboard emulators. Keyboard emulators include speech input software, sip-and-puff software, on-screen keyboards, scanning software and a variety of assistive technologies and alternate keyboards. Individuals with low vision also may have trouble tracking a pointer and find the use of software much easier (or only possible) if they can control it from the keyboard. Examples of "specific timings for individual keystrokes" include situations where a user would be required to repeat or execute multiple keystrokes within a short period of time or where a key must be held down for an extended period before the keystroke is registered. The phrase "except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints" is included to separate those things that cannot reasonably be controlled from a keyboard. Most actions carried out by a pointing device can also be done from the keyboard (for example, clicking, selecting, moving, sizing). However, there is a small class of input that is done with a pointing device that cannot be done from the keyboard in any known fashion without requiring an inordinate number of keystrokes. Free hand drawing, watercolor painting, and flying a helicopter through an obstacle course are all examples of functions that require path dependent input. Drawing straight lines, regular geometric shapes, re-sizing windows and dragging objects to a location (when the path to that location is not relevant) do not require path dependent input. The use of MouseKeys would not satisfy this Success Criterion because it is not a keyboard equivalent to the application; it is a mouse equivalent (i.e., it looks like a mouse to the application). It is assumed that the design of user input features takes into account that operating system keyboard accessibility features may be in use. For example, modifier key locking may be turned on. Content continues to function in such an environment, not sending events that would collide with the modifier key lock to produce unexpected results. Specific Benefits of Success Criterion 2.1.1 People who are blind (who cannot use devices such as mice that require eye-hand coordination) People with low vision (who may have trouble finding or tracking a pointer indicator on screen) Some people with hand tremors find using a mouse very difficult and therefore usually use a keyboard Success Criterion 2.1.2: No Keyboard Trap (Level A) From Success Criterion 2.1.2 If keyboard focus can be moved to a component of the page using a keyboard interface Note: Conformance Requirement 5: Non-Interference Additional Guidance When Applying Success Criterion 2.1.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 2.1.2 With these substitutions, it would read: 2.1.2 No Keyboard Trap: non-web document software keyboard interface Note: non-web document software non-web document software Note: Intent from Understanding Success Criterion 2.1.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.1.2 The intent of this Success Criterion is to ensure that that content does not "trap" keyboard focus within subsections of content on a Web page. This is a common problem when multiple formats are combined within a page and rendered using plug-ins or embedded applications. There may be times when the functionality of the Web page restricts the focus to a subsection of the content, as long as the user knows how to leave that state and "untrap" the focus. Specific Benefits of Success Criterion 2.1.2 People who rely on a keyboard or keyboard interface to use the Web including people who are blind and people with physical disabilities. Guideline 2.2: Enough Time From Guideline 2.2 Provide users enough time to read and use content. Additional Guidance When Applying Guideline 2.2 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 2.2 applies directly as written. Intent from Understanding Guideline 2.2 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 2.2 Many users who have disabilities need more time to complete tasks than the majority of users: they may take longer to physically respond, they may take longer to read things, they may have low vision and take longer to find things or to read them, or they may be accessing content through an assistive technology that requires more time. This guideline focuses on ensuring that users are able to complete the tasks required by the content with their own individual response times. The primary approaches deal with eliminating time constraints or providing users enough additional time to allow them to complete their tasks. Exceptions are provided for those cases where this is not possible. Success Criterion 2.2.1: Timing Adjustable (Level A) From Success Criterion 2.2.1 For each time limit that is set by the content, at least one of the following is true: Turn off: Adjust: Extend: Real-time Exception: Essential Exception: essential 20 Hour Exception: Note: Success Criterion 3.2.1 Additional Guidance When Applying Success Criterion 2.2.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 2.2.1 With this substitution, it would read: 2.2.1 Timing Adjustable: non-web documents software Turn off: Adjust: Extend: Real-time Exception: Essential Exception: essential 20 Hour Exception: Note: Success Criterion 3.2.1 Intent from Understanding Success Criterion 2.2.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.2.1 The intent of this Success Criterion is to ensure that users with disabilities are given adequate time to interact with Web content whenever possible. People with disabilities such as blindness, low vision, dexterity impairments, and cognitive limitations may require more time to read content or to perform functions such as filling out on-line forms. If Web functions are time-dependent, it will be difficult for some users to perform the required action before a time limit occurs. This may render the service inaccessible to them. Designing functions that are not time-dependent will help people with disabilities succeed at completing these functions. Providing options to disable time limits, customize the length of time limits, or request more time before a time limit occurs helps those users who require more time than expected to successfully complete tasks. These options are listed in the order that will be most helpful for the user. Disabling time limits is better than customizing the length of time limits, which is better than requesting more time before a time limit occurs. Any process that happens without user initiation after a set time or on a periodic basis is a time limit. This includes partial or full updates of content (for example, page refresh), changes to content, or the expiration of a window of opportunity for a user to react to a request for input. It also includes content that is advancing or updating at a rate beyond the user's ability to read and/or understand it. In other words, animated, moving or scrolling content introduces a time limit on a users ability to read content. In some cases, however, it is not possible to change the time limit (for example, for an auction or other real-time event) and exceptions are therefore provided for those cases. Notes regarding server time limits Timed server redirects can be found below under Common Failures. Non-timed server redirects (e.g., 3xx response codes) are not applicable because there is no time limit: they work instantly. This Success Criterion applies only to time limits that are set by the content itself. For example, if a time limit is included in order to address security concerns, it would be considered to have been set by the content because it is designed to be part of the presentation and interaction experience for that content. Time limits set externally to content, such as by the user agent or by factors intrinsic to the Internet are not under the author's control and not subject to WCAG conformance requirements. Time limits set by Web servers should be under the author's/organization's control and are covered. (Success Criteria 2.2.3 2.2.4 2.2.5 Ten times the default was chosen based on clinical experience and other guidelines. For example, if 15 seconds is allowed for a user to respond and hit a switch, 150 seconds would be sufficient to allow almost all users to hit a switch even if they had trouble. 20 seconds was also based on clinical experience and other guidelines. 20 seconds to hit 'any switch' is sufficient for almost all users including those with spasticity. Some would fail, but some would fail all lengths of time. A reasonable period for requesting more time is required since an arbitrarily long time can provide security risks to all users, including those with disabilities, for some applications. For example, with kiosks or terminals that are used for financial transactions, it is quite common for people to walk away without signing off. This leaves them vulnerable to those walking up behind them. Providing a long period of inactivity before asking, and then providing a long period for the person to indicate that they are present can leave terminals open for abuse. If there is no activity the system should ask if the user is there. It should then ask for an indication that a person is there ('hit any key') and then wait long enough for almost anyone to respond. For "hit any key," 20 seconds would meet this. If the person indicates that they are still present, the device should return the user to the exact condition that existed before it asked the question. 20 hours was chosen as an upper limit because it is longer than a full waking day. In cases where timing is not an intrinsic requirement but giving users control over timed events would invalidate the outcome, a third party can control the time limits for the user (for example, granting double time on a test). See also Understanding Success Criterion 2.2.3 No Timing Specific Benefits of Success Criterion 2.2.1 People with physical disabilities often need more time to react, to type and to complete activities. People with low vision need more time to locate things on screen and to read. People who are blind and using screen readers may need more time to understand screen layouts, to find information and to operate controls. People who have cognitive or language limitations need more time to read and to understand. People who are deaf and communicate in sign language may need more time to read information printed in text (which may be a second language for some). In circumstances where a sign-language interpreter may be relating audio content to a user who is deaf, control over time limits is also important. People with reading disabilities, cognitive limitations, and learning disabilities who may need more time to read or comprehend information can have additional time to read the information by pausing the content. Success Criterion 2.2.2: Pause, Stop, Hide (Level A) From Success Criterion 2.2.2 For moving, blinking Moving, blinking, scrolling: pause essential Auto-updating: Note 1: Guideline 2.3 Note 2: Conformance Requirement 5: Non-Interference Note 3: Note 4: Additional Guidance When Applying Success Criterion 2.2.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 2.2.2 With this substitution, it would read: 2.2.2 Pause, Stop, Hide: blinking Moving, blinking, scrolling: pause essential Auto-updating: Note 1: Guideline 2.3 Note 2: content non-web documents software non-web documents software Note 3: Content Note 4: content Note: content Intent from Understanding Success Criterion 2.2.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.2.2 The intent of this Success Criterion is to avoid distracting users during their interaction with a Web page. "Moving, blinking and scrolling" refers to content in which the visible content conveys a sense of motion. Common examples include motion pictures, synchronized media presentations, animations, real-time games, and scrolling stock tickers. "Auto-updating" refers to content that updates or disappears based on a preset time interval. Common time-based content includes audio, automatically updated weather information, news, stock price updates, and auto-advancing presentations and messages. The requirements for moving, blinking and scrolling content and for auto-updating content are the same except that: authors have the option of providing the user with a means to control the frequency of updates when content is auto-updating and there is no five Content that moves or auto-updates can be a barrier to anyone who has trouble reading stationary text quickly as well as anyone who has trouble tracking moving objects. It can also cause problems for screen readers. Moving content can also be a severe distraction for some people. Certain groups, particularly those with attention deficit disorders, find blinking content distracting, making it difficult for them to concentrate on other parts of the Web page. Five seconds was chosen because it is long enough to get a user's attention, but not so long that a user cannot wait out the distraction if necessary to use the page. Content that is paused can either resume in real-time or continue playing from the point in the presentation where the user left off. Pausing and resuming where the user left off is best for users who want to pause to read content and works best when the content is not associated with a real-time event or status. Note: Understanding Success Criterion 2.2.1 Timing Adjustable Pausing and jumping to current display (when pause is released) is better for information that is real-time or "status" in nature. For example, weather radar, a stock ticker, a traffic camera, or an auction timer, would present misleading information if a pause caused it to display old information when the content was restarted. Note: For a mechanism to be considered "a mechanism for the user to pause," it must provide the user with a means to pause that does not tie up the user or the focus so that the page cannot be used. The word "pause" here is meant in the sense of a "pause button" although other mechanisms than a button can be used. Having an animation stop only so long as a user has focus on it (where it restarts as soon as the user moves the focus away) would not be considered a "mechanism for the user to pause" because it makes the page unusable in the process and would not meet this SC. It is important to note that the terms "blinking" and "flashing" can sometimes refer to the same content. "Blinking" refers to content that causes a distraction problem. Blinking can be allowed for a short time as long as it stops (or can be stopped) "Flashing" refers to content that can trigger a seizure (if it is more than 3 per second and large and bright enough). This cannot be allowed even for a second or it could cause a seizure. And turning the flash off is also not an option since the seizure could occur faster than most users could turn it off. Blinking usually does not occur at speeds of 3 per second or more, but it can. If blinking occurs faster than 3 per second, it would also be considered a flash. Specific Benefits of Success Criterion 2.2.2 Providing content that stops blinking after five seconds or providing a mechanism for users to stop blinking content allows people with certain disabilities to interact with the Web page. One use of content that blinks is to draw the visitor's attention to that content. Although this is an effective technique for all users with vision, it can be a problem for some users if it persists. For certain groups, including people with low literacy, reading and intellectual disabilities, and people with attention deficit disorders, content that blinks may make it difficult or even impossible to interact with the rest of the Web page. Guideline 2.3: Seizures From Guideline 2.3 Do not design content in a way that is known to cause seizures. Additional Guidance When Applying Guideline 2.3 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 2.3 applies directly as written. Intent from Understanding Guideline 2.3 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 2.3 Some people with seizure disorders can have a seizure triggered by flashing visual content. Most people are unaware that they have this disorder until it strikes. In 1997, a cartoon on television in Japan sent over 700 children to the hospital, including about 500 who had seizures. Warnings do not work well because they are often missed, especially by children who may in fact not be able to read them. The objective of this guideline is to ensure that content that is marked as conforming to WCAG 2.0 avoids the types of flash that are most likely to cause seizure when viewed even for a second or two. Success Criterion 2.3.1: Three Flashes or Below Threshold (Level A) From Success Criterion 2.3.1 Web pages flash general flash and red flash thresholds Note: Conformance Requirement 5: Non-Interference Additional Guidance When Applying Success Criterion 2.3.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 2.3.1 With these substitutions, it would read: 2.3.1 Three Flashes or Below Threshold: Non-web documents software flash general flash and red flash thresholds Note: non-web document software non-web document software Intent from Understanding Success Criterion 2.3.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.3.1 The intent of this Success Criterion is to allow users to access the full content of a site without inducing seizures due to photosensitivity. Individuals who have photosensitive seizure disorders can have a seizure triggered by content that flashes at certain frequencies for more than a few flashes. People are even more sensitive to red flashing than to other colors, so a special test is provided for saturated red flashing. These guidelines are based on guidelines for the broadcasting industry as adapted for computer screens, where content is viewed from a closer distance (using a larger angle of vision). Flashing can be caused by the display, the computer rendering the image or by the content being rendered. The author has no control of the first two. They can be addressed by the design and speed of the display and computer. The intent of this criterion is to ensure that flicker that violates the flash thresholds is not caused by the content itself. For example, the content could contain a video clip or animated image of a series of strobe flashes, or close-ups of rapid-fire explosions. This Success Criterion replaces a much more restrictive criterion in WCAG 1.0 that did not allow any flashing (even of a single pixel) within a broad frequency range (3 to 50 Hz). This Success Criterion is based on existing specifications in use in the UK and by others for television broadcast and has been adapted for computer display viewing. The 1024 x 768 screen is used as the reference screen resolution for the evaluation. The 341 x 256 pixel block represents a 10 degree viewport at a typical viewing distance. (The 10 degree field is taken from the original specifications and represents the central vision portion of the eye, where people are most susceptible to photo stimuli.) The combined area of flashes occurring concurrently and contiguously means the total area that is actually flashing at the same time. It is calculated by adding up the contiguous area that is flashing simultaneously within any 10 degree angle of view. Note: "Blinking" refers to content that causes a distraction problem. Blinking can be allowed for a short time as long as it stops (or can be stopped) "Flashing" refers to content that can trigger a seizure (if it is more than 3 per second and large and bright enough). This cannot be allowed even for a second or it could cause a seizure. And turning the flash off is also not an option since the seizure could occur faster than most users could turn it off. Blinking usually does not occur at speeds of 3 per second or more, but it can. If blinking occurs faster than 3 per second, it would also be considered a flash. Specific Benefits of Success Criterion 2.3.1 Individuals who have seizures when viewing flashing material will be able to view all of the material on a site without having a seizure and without having to miss the full experience of the content by being limited to text alternatives. This includes people with photosensitive epilepsy as well as other photosensitive seizure disorders. Guideline 2.4: Navigable From Guideline 2.4 Provide ways to help users navigate, find content, and determine where they are. Additional Guidance When Applying Guideline 2.4 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 2.4 applies directly as written. Intent from Understanding Guideline 2.4 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 2.4 The intent of this guideline is to help users find the content they need and allow them to keep track of their location. These tasks are often more difficult for people with disabilities. For finding, navigation, and orientation, it is important that the user can find out what the current location is. For navigation, information about the possible destinations needs to be available. Screen readers convert content to synthetic speech which, because it is audio, must be presented in linear order. Some Success Criteria in this guideline explain what provisions need to be taken to ensure that screen reader users can successfully navigate the content. Others allow users to more easily recognize navigation bars and page headers and to bypass this repeated content. Unusual user interface features or behaviors may confuse people with cognitive disabilities. As described in The Motive Web Design Glossary to tell the user where they are to enable the user to go somewhere else This guideline works closely with Guideline 1.3 Success Criterion 1.3.1 Success Criterion 2.4.1: Bypass Blocks (Level A) From Success Criterion 2.4.1 A mechanism Web pages Additional Guidance When Applying Success Criterion 2.4.1 to Non-Web Documents and Software: This applies directly as written and described in Intent from Understanding Success Criterion 2.4.1 With these substitutions, this success criterion would read: (for non-web documents) 2.4.1 Bypass Blocks: non-web documents set of non-web documents (for software programs) 2.4.1 Bypass Blocks: software programs set of software programs Note 1 set of documents set of software programs Note 2: Note 3: within Note 4: Intent from Understanding Success Criterion 2.4.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.4.1 The intent of this Success Criterion is to allow people who navigate sequentially through content more direct access to the primary content of the Web page. Web pages and applications often have content that appears on other pages or screens. Examples of repeated blocks of content include but are not limited to navigation links, heading graphics, and advertising frames. Small repeated sections such as individual words, phrases or single links are not considered blocks for the purposes of this provision. This is in contrast to a sighted user's ability to ignore the repeated material either by focusing on the center of the screen (where main content usually appears) or a mouse user's ability to select a link with a single mouse click rather than encountering every link or form control that comes before the item they want. It is not the intent of this Success Criterion to require authors to provide methods that are redundant to functionality provided by the user agent. Most web browsers provide keyboard shortcuts to move the user focus to the top of the page, so if a set of navigation links is provided at the bottom of a web page providing a "skip" link may be unnecessary. Note: Although the success criterion does not specifically use the term “within a set of web pages”, the concept of the pages belonging to a set is implied. An author would not be expected to avoid any possible duplication of content in any two pages that are not in some way related to each other; that are not "Web pages that share a common purpose and that are created by the same author, group or organization” (the definition of set of web pages). Note: Specific Benefits of Success Criterion 2.4.1 When this Success Criterion is not satisfied, it may be difficult for people with some disabilities to reach the main content of a Web page quickly and easily. Screen reader users who visit several pages on the same site can avoid having to hear all heading graphics and dozens of navigation links on every page before the main content is spoken. People who use only the keyboard or a keyboard interface can reach content with fewer keystrokes. Otherwise, they might have to make dozens of keystrokes before reaching a link in the main content area. This can take a long time and may cause severe physical pain for some users. People who use screen magnifiers do not have to search through the same headings or other blocks of information to find where the content begins each time they enter a new page. People with cognitive limitations as well as people who use screen readers may benefit when links are grouped into lists Success Criterion 2.4.2: Page Titled (Level A) From Success Criterion 2.4.2 Web pages Additional Guidance When Applying Success Criterion 2.4.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 2.4.2 With this substitution, it would read: 2.4.2 Page Titled: Non-web documents software Note 1: non-web software application non-web document Note 2: Closed Functionality Intent from Understanding Success Criterion 2.4.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.4.2 The intent of this Success Criterion is to help users find content and orient themselves within it by ensuring that each Web page has a descriptive title. Titles identify the current location without requiring users to read or interpret page content. When titles appear in site maps or lists of search results, users can more quickly identify the content they need. User agents make the title of the page easily available to the user for identifying the page. For instance, a user agent may display the page title in the window title bar or as the name of the tab containing the page. In cases where the page is a document or a web application, the name of the document or web application would be sufficient to describe the purpose of the page. Note that it is not required to use the name of the document or web application; other things may also describe the purpose or the topic of the page. Success Criteria 2.4.4 2.4.9 Specific Benefits of Success Criterion 2.4.2 This criterion benefits all users in allowing users to quickly and easily identify whether the information contained in the Web page is relevant to their needs. People with visual disabilities will benefit from being able to differentiate content when multiple Web pages are open. People with cognitive disabilities, limited short-term memory and reading disabilities also benefit from the ability to identify content by its title. This criterion also benefits people with severe mobility impairments whose mode of operation relies on audio when navigating between Web pages. Success Criterion 2.4.3: Focus Order (Level A) From Success Criterion 2.4.3 If a Web page navigated sequentially Additional Guidance When Applying Success Criterion 2.4.3 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 2.4.3 With this substitution, it would read: 2.4.3 Focus Order: non-web documents software Intent from Understanding Success Criterion 2.4.3 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.4.3 The intent of this Success Criterion is to ensure that when users navigate sequentially through content, they encounter information in an order that is consistent with the meaning of the content and can be operated from the keyboard. This reduces confusion by letting users form a consistent mental model of the content. There may be different orders that reflect logical relationships in the content. For example, moving through components in a table one row at a time or one column at a time both reflect the logical relationships in the content. Either order may satisfy this Success Criterion. The way that sequential navigation order is determined in Web content is defined by the technology of the content. For example, simple HTML defines sequential navigation via the notion of tabbing order. Dynamic HTML may modify the navigation sequence using scripting along with the addition of a tabindex attribute to allow focus to additional elements. If no scripting or tabindex attributes are used, the navigation order is the order that components appear in the content stream. (See HTML 4.01 Specification, section 17.11, "Giving focus to an element"). An example of keyboard navigation that is not the sequential navigation addressed by this Success Criterion is using arrow key navigation to traverse a tree component. The user can use the up and down arrow keys to move from tree node to tree node. Pressing the right arrow key may expand a node, then using the down arrow key, will move into the newly expanded nodes. This navigation sequence follows the expected sequence for a tree control - as additional items get expanded or collapsed, they are added or removed from the navigation sequence. The focus order may not be identical to the programmatically determined reading order (see Success Criterion 1.3.2) as long as the user can still understand and operate the Web page. Since there may be several possible logical reading orders for the content, the focus order may match any of them. However, when the order of a particular presentation differs from the programmatically determined reading order, users of one of these presentations may find it difficult to understand or operate the Web page. Authors should carefully consider all these users as they design their Web pages. For example, a screen reader user interacts with the programmatically determined reading order, while a sighted keyboard user interacts with the visual presentation of the Web page. Care should be taken so that the focus order makes sense to both of these sets of users and does not appear to either of them to jump around randomly. For clarity: Focusable components need to receive focus in an order that preserves meaning and operability only when navigation sequences affect meaning and operability. In those cases where it is required, there may be more than one order that will preserve meaning and operability. If there is more than one order that preserves meaning and operability, only one of them needs to be provided. Specific Benefits of Success Criterion 2.4.3 These techniques benefit keyboard users who navigate documents sequentially and expect the focus order to be consistent with the sequential reading order. People with mobility impairments who must rely on keyboard access for operating a page benefit from a logical, usable focus order. People with disabilities that make reading difficult can become disoriented when tabbing takes focus someplace unexpected. They benefit from a logical focus order. People with visual impairments can become disoriented when tabbing takes focus someplace unexpected or when they cannot easily find the content surrounding an interactive element. Only a small portion of the page may be visible to an individual using a screen magnifier at a high level of magnification. Such a user may interpret a field in the wrong context if the focus order is not logical. Success Criterion 2.4.4: Link Purpose (In Context) (Level A) From Success Criterion 2.4.4 The purpose of each link programmatically determined link context ambiguous to users in general Additional Guidance When Applying Success Criterion 2.4.4 to Non-Web Documents and Software: This applies directly as written and as described in Intent from Understanding Success Criterion 2.4.4 Note: Intent from Understanding Success Criterion 2.4.4 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.4.4 The intent of this Success Criterion is to help users understand the purpose of each link so they can decide whether they want to follow the link. Whenever possible, provide link text that identifies the purpose of the link without needing additional context. Assistive technology has the ability to provide users with a list of links that are on the Web page. Link text that is as meaningful as possible will aid users who want to choose from this list of links. Meaningful link text also helps those who wish to tab from link to link. Meaningful links help users choose which links to follow without requiring complicated strategies to understand the page. The text of, or associated with, the link is intended to describe the purpose of the link. In cases where the link takes one to a document or a web application, the name of the document or web application would be sufficient to describe the purpose of the link (which is to take you to the document or web application). Note that it is not required to use the name of the document or web application; other things may also describe the purpose of the link. Success Criterion 2.4.2 In some situations, authors may want to provide part of the description of the link in logically related text that provides the context for the link. In this case the user should be able to identify the purpose of the link without moving focus from the link. In other words, they can arrive on a link and find out more about it without losing their place. This can be achieved by putting the description of the link in the same sentence, paragraph, list item, the heading immediately preceding the link, or table cell as the link, or in the table header cell for a link in a data table, because these are directly associated with the link itself. This context will be most usable if it precedes the link. (For instance, if you must use ambiguous link text, it is better to put it at the end of the sentence that describes its destination, rather than putting the ambiguous phrase at the beginning of the sentence.) If the description follows the link, there can be confusion and difficulty for screen reader users who are reading through the page in order (top to bottom). Links with the same destination should have the same descriptions (per Success Criterion 3.2.4 The Success Criterion includes an exception for links for which the purpose of the link cannot be determined from the information on the Web page. In this situation, the person with the disability is not at a disadvantage; there is no additional context available to understand the link purpose. However, whatever amount of context is available on the Web page that can be used to interpret the purpose of the link must be made available in the link text or programmatically associated with the link to satisfy the Success Criterion. Note: See also Understanding Success Criterion 2.4.9 Link Purpose (Link Only) Specific Benefits of Success Criterion 2.4.4 This Success Criterion helps people with motion impairment by letting them skip links that they are not interested in, avoiding the keystrokes needed to visit the referenced content and then returning to the current content. People with cognitive limitations will not become disoriented by multiple means of navigation to and from content they are not interested in. People with visual disabilities will be able to determine the purpose of a link by exploring the link's context. Success Criterion 2.4.5: Multiple Ways (Level AA) From Success Criterion 2.4.5 More than one way is available to locate a Web page set of Web pages process Additional Guidance When Applying Success Criterion 2.4.5 to Non-Web Documents and Software: This applies directly as written and described in Intent from Understanding Success Criterion 2.4.5 With these substitutions, this success criterion would read: (for non-web documents) 2.4.5 Multiple Ways: non-web document set of non-web documents non-web document (for software programs) 2.4.5 Multiple Ways: software program set of software programs software program Note 1 set of documents set of software programs Note 2: set of documents set of software programs Note 3: Note 4: Note 5: set of documents set of software programs Intent from Understanding Success Criterion 2.4.5 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.4.5 The intent of this Success Criterion is to make it possible for users to locate content in a manner that best meets their needs. Users may find one technique easier or more comprehensible to use than another. Even small sites should provide users some means of orientation. For a three or four page site, with all pages linked from the home page, it may be sufficient simply to provide links from and to the home page where the links on the home page can also serve as a site map. Specific Benefits of Success Criterion 2.4.5 Providing an opportunity to navigate sites in more than one manner can help people find information faster. Users with visual impairments may find it easier to navigate to the correct part of the site by using a search, rather than scrolling through a large navigation bar using a screen magnifier or screen reader. A person with cognitive disabilities may prefer a table of contents or site map that provides an overview of the site rather than reading and traversing through several Web pages. Some users may prefer to explore the site in a sequential manner, moving from Web page to Web page in order to best understand the concepts and layout. Individuals with cognitive limitations may find it easier to use search features than to use a hierarchical navigation scheme that be difficult to understand. Success Criterion 2.4.6: Headings and Labels (Level AA) From Success Criterion 2.4.6 Headings and labels Additional Guidance When Applying Success Criterion 2.4.6 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 2.4.6 Note: software content Intent from Understanding Success Criterion 2.4.6 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.4.6 The intent of this Success Criterion is to help users understand what information is contained in Web pages and how that information is organized. When headings are clear and descriptive, users can find the information they seek more easily, and they can understand the relationships between different parts of the content more easily. Descriptive labels help users identify specific components within the content. Labels and headings do not need to be lengthy. A word, or even a single character, may suffice if it provides an appropriate cue to finding and navigating content. Note: Understanding Success Criterion 1.3.1 Info and Relationships Specific Benefits of Success Criterion 2.4.6 Descriptive headings are especially helpful for users who have disabilities that make reading slow and for people with limited short-term memory. These people benefit when section titles make it possible to predict what each section contains. People who have difficulty using their hands or who experience pain when doing so will benefit from techniques that reduce the number of keystrokes required to reach the content they need. This Success Criterion helps people who use screen readers by ensuring that labels and headings are meaningful when read out of context, for example, in a Table of Contents, or when jumping from heading to heading within a page. This Success Criterion may also help users with low vision who can see only a few words at a time. Success Criterion 2.4.7: Focus Visible (Level AA) From Success Criterion 2.4.7 Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible. Additional Guidance When Applying Success Criterion 2.4.7 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 2.4.7 Intent from Understanding Success Criterion 2.4.7 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 2.4.7 The purpose of this success criterion is to help a person know which element has the keyboard focus. The purpose of this success criterion is to help a person know which element among multiple elements has the keyboard focus. If there is only one keyboard actionable control on the screen, the success criterion would be met because the visual design presents only one keyboard actionable item. Note that a keyboard focus indicator can take different forms. One common way is a caret within the text field to indicate that the text field has the keyboard focus. Another is a visual change to a button to indicate that that button has the keyboard focus. Specific Benefits of Success Criterion 2.4.7 This Success Criterion helps anyone who relies on the keyboard to operate the page, by letting them visually determine the component on which keyboard operations will interact at any point in time. People with attention limitations, short term memory limitations, or limitations in executive processes benefit by being able to discover where the focus is located. Principle 3: Understandable From Principle 3 Information and the operation of user interface must be understandable. Additional Guidance When Applying Principle 3 to Non-Web Documents and Software: In WCAG 2.0, the Principles are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Principle 3 applies directly as written. Guideline 3.1: Readable From Guideline 3.1 Make text content readable and understandable. Additional Guidance When Applying Guideline 3.1 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 3.1 applies directly as written. Intent from Understanding Guideline 3.1 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 3.1 The intent of this guideline is to allow text content to be read by users and by assistive technology, and to ensure that information necessary for understanding it is available. People with disabilities experience text in many different ways. For some the experience is visual; for some it is auditory; for some it is tactile; for still others it is both visual and auditory. Some users experience great difficulty in recognizing written words yet understand extremely complex and sophisticated documents when the text is read aloud, or when key processes and ideas are illustrated visually or interpreted as sign language. For some users, it is difficult to infer the meaning of a word or phrase from context, especially when the word or phrase is used in an unusual way or has been given a specialized meaning; for these users the ability to read and understand may depend on the availability of specific definitions or the expanded forms of acronyms or abbreviations. User agents, including speech-enabled as well as graphical applications, may be unable to present text correctly unless the language and direction of the text are identified; while these may be minor problems for most users, they can be enormous barriers for users with disabilities. In cases where meaning cannot be determined without pronunciation information (for example, certain Japanese Kanji characters), pronunciation information must be available as well Success Criterion 3.1.1: Language of Page (Level A) From Success Criterion 3.1.1 The default human language Web page programmatically determined Additional Guidance When Applying Success Criterion 3.1.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 3.1.1 With these substitutions, it would read: 3.1.1 Language of Page: human language non-web documents software programmatically determined Note 1: accessibility-supported software assistive technologies Note 2: Closed Functionality Intent from Understanding Success Criterion 3.1.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.1.1 The intent of this Success Criterion is to ensure that content developers provide information in the Web page that user agents need to present text and other linguistic content correctly. Both assistive technologies and conventional user agents can render text more accurately when the language of the Web page is identified. Screen readers can load the correct pronunciation rules. Visual browsers can display characters and scripts correctly. Media players can show captions correctly. As a result, users with disabilities will be better able to understand the content. The default human language of the Web page is the default text-processing language as discussed in Internationalization Best Practices: Specifying Language in XHTML & HTML Content Note: Specific Benefits of Success Criterion 3.1.1 This Success Criterion helps: people who use screen readers or other technologies that convert text into synthetic speech; people who find it difficult to read written material with fluency and accuracy, such as recognizing characters and alphabets or decoding words; people with certain cognitive, language and learning disabilities who use text-to-speech software people who rely on captions for synchronized media. Success Criterion 3.1.2: Language of Parts (Level AA) From Success Criterion 3.1.2 The human language programmatically determined Additional Guidance When Applying Success Criterion 3.1.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 3.1.2 With these substitutions, it would read: 3.1.2 Language of Parts: human language non-web document software programmatically determined Note 1: software non-web document non-web document Note 2: Closed Functionality Intent from Understanding Success Criterion 3.1.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.1.2 The intent of this Success Criterion is to ensure that user agents can correctly present content written in multiple languages. This makes it possible for user agents and assistive technologies to present content according to the presentation and pronunciation rules for that language. This applies to graphical browsers as well as screen readers, braille displays, and other voice browsers. Both assistive technologies and conventional user agents can render text more accurately if the language of each passage of text is identified. Screen readers can use the pronunciation rules of the language of the text. Visual browsers can display characters and scripts in appropriate ways. This is especially important when switching between languages that read from left to right and languages that read from right to left, or when text is rendered in a language that uses a different alphabet. Users with disabilities who know all the languages used in the Web page will be better able to understand the content when each passage is rendered appropriately. When no other language has been specified for a phrase or passage of text, its human language is the default human language of the Web page (see Success Criterion 3.1.1). So the human language of all content in single language documents can be programmatically determined. Individual words or phrases in one language can become part of another language. For example, "rendezvous" is a French word that has been adopted in English, appears in English dictionaries, and is properly pronounced by English screen readers. Hence a passage of English text may contain the word "rendezvous" without specifying that its human language is French and still satisfy this Success Criterion. Frequently, when the human language of text appears to be changing for a single word, that word has become part of the language of the surrounding text. Because this is so common in some languages, single words should be considered part of the language of the surrounding text unless it is clear that a change in language was intended. If there is doubt whether a change in language is intended, consider whether the word would be pronounced the same (except for accent or intonation) in the language of the immediately surrounding text. Most professions require frequent use of technical terms which may originate from a foreign language. Such terms are usually not translated to all languages. The universal nature of technical terms also facilitate communication between professionals. Some common examples of technical terms include: Homo sapiens, Alpha Centauri, hertz, and habeas corpus. Identifying changes in language is important for a number of reasons: It allows braille translation software to follow changes in language, e.g., substitute control codes for accented characters, and insert control codes necessary to prevent erroneous creation of Grade 2 braille contractions. Speech synthesizers that support multiple languages will be able to speak the text in the appropriate accent with proper pronunciation. If changes are not marked, the synthesizer will try its best to speak the words in the default language it works in. Thus, the French word for car, "voiture" would be pronounced "voyture" by a speech synthesizer that uses English as its default language. Marking changes in language can benefit future developments in technology, for example users who are unable to translate between languages themselves will be able to use machines to translate unfamiliar languages. Marking changes in language can also assist user agents in providing definitions using a dictionary. Specific Benefits of Success Criterion 3.1.2 This Success Criterion helps: people who use screen readers or other technologies that convert text into synthetic speech; people who find it difficult to read written material with fluency and accuracy, such as recognizing characters and alphabets, decoding words, and understanding words and phrases; people with certain cognitive, language and learning disabilities who use text-to-speech software; people who rely on captions to recognize language changes in the soundtrack of synchronized media content. Guideline 3.2: Predictable From Guideline 3.2 Make Web pages appear and operate in predictable ways. Additional Guidance When Applying Guideline 3.2 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 3.2 applies directly as written, replacing “web pages” with “non-web documents or software”. With this substitution, this guideline would read: Guideline 3.2 Predictable: Make non-web documents software Intent from Understanding Guideline 3.2 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 3.2 The intent of this Guideline is to help users with disabilities by presenting content in a predictable order from Web page to Web page and by making the behavior of functional and interactive components predictable. It is difficult for some users to form an overview of the Web page: screen readers present content as a one-dimensional stream of synthetic speech that makes it difficult to understand spatial relationships. Users with cognitive limitations may become confused if components appear in different places on different pages. For example, people who use screen magnifiers see only part of the screen at any point in time; a consistent layout makes it easier for them to find navigation bars and other components. Placing repeated components in the same relative order within a set of Web pages allows users with reading disabilities to focus on an area of the screen rather than spending additional time decoding the text of each link. Users with limited use of their hands can more easily determine how to complete their tasks using the fewest keystrokes. Success Criterion 3.2.1: On Focus (Level A) From Success Criterion 3.2.1 When any component receives focus, it does not initiate a change of context Additional Guidance When Applying Success Criterion 3.2.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 3.2.1 Note: change of context Intent from Understanding Success Criterion 3.2.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.2.1 The intent of this Success Criterion is to ensure that functionality is predictable as visitors navigate their way through a document. Any component that is able to trigger an event when it receives focus must not change the context. Examples of changing context when a component receives focus include, but are not limited to: forms submitted automatically when a component receives focus; new windows launched when a component receives focus; focus is changed to another component when that component receives focus; Focus may be moved to a control either via the keyboard ( e.g. e.g. e.g. Note: Specific Benefits of Success Criterion 3.2.1 This Success Criterion helps people with visual disabilities, cognitive limitations, and motor impairments by reducing the chance that a change of context will occur unexpectedly. Success Criterion 3.2.2: On Input (Level A) From Success Criterion 3.2.2 Changing the setting of any user interface component change of context Additional Guidance When Applying Success Criterion 3.2.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 3.2.2 Intent from Understanding Success Criterion 3.2.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.2.2 The intent of this Success Criterion is to ensure that entering data or selecting a form control has predictable effects. Changing the setting of any user interface component is changing some state in the control that will persist when the user is no longer interacting with it. So checking a checkbox or entering text into a text field changes its setting, but activating a link or a button does not. Changes in context can confuse users who do not easily perceive the change or are easily distracted by changes. Changes of context are appropriate only when it is clear that such a change will happen in response to the user's action. Note: Note: Specific Benefits of Success Criterion 3.2.2 This Success Criterion helps users with disabilities by making interactive content more predictable. Unexpected changes of context can be so disorienting for users with visual disabilities or cognitive limitations that they are unable to use the content. Individuals who are unable to detect changes of context are less likely to become disoriented while navigating a site. For example: Individuals who are blind or have low vision may have difficulty knowing when a visual context change has occurred, such as a new window popping up. In this case, warning users of context changes in advance minimizes confusion when the user discovers that the back button no longer behaves as expected. Some individuals with low vision, with reading and intellectual disabilities, and others who have difficulty interpreting visual cues may benefit from additional cues in order to detect changes of context. Success Criterion 3.2.3: Consistent Navigation (Level AA) From Success Criterion 3.2.3 Navigational mechanisms that are repeated on multiple Web pages set of Web pages same relative order Additional Guidance When Applying Success Criterion 3.2.3 to Non-Web Documents and Software: This applies directly as written and described in Intent from Understanding Success Criterion 3.2.3 With these substitutions, this success criterion would read: (for non-web documents) 3.2.3 Consistent Navigation: non-web documents set of non-web documents (for software programs) 3.2.3 Consistent Navigation: software programs set of software programs Note 1: set of documents set of software programs Note 2: within Intent from Understanding Success Criterion 3.2.3 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.2.3 The intent of this Success Criterion is to encourage the use of consistent presentation and layout for users who interact with repeated content within a set of Web pages and need to locate specific information or functionality more than once. Individuals with low vision who use screen magnification to display a small portion of the screen at a time often use visual cues and page boundaries to quickly locate repeated content. Presenting repeated content in the same order is also important for visual users who use spatial memory or visual cues within the design to locate repeated content. It is important to note that the use of the phrase "same order" in this section is not meant to imply that subnavigation menus cannot be used or that blocks of secondary navigation or page structure cannot be used. Instead, this Success Criterion is intended to assist users who interact with repeated content across Web pages to be able to predict the location of the content they are looking for and find it more quickly when they encounter it again. Users may initiate a change in the order by using adaptive user agents or by setting preferences so that the information is presented in a way that is most useful to them. Specific Benefits of Success Criterion 3.2.3 Ensuring that repeated components occur in the same order on each page of a site helps users become comfortable that they will able to predict where they can find things on each page. This helps users with cognitive limitations low vision intellectual disabilities blind Success Criterion 3.2.4: Consistent Identification (Level AA) From Success Criterion 3.2.4 Components that have the same functionality Web pages Additional Guidance When Applying Success Criterion 3.2.4 to Non-Web Documents and Software: This applies directly as written and described in Intent from Understanding Success Criterion 3.2.4 With these substitutions, this success criterion would read: (for non-web documents) 3.2.4 Consistent Identification: same functionality set of non-web documents (for programs) 3.2.4 Consistent Identification: same functionality set of software programs Note 1 set of documents set of software programs Note 2: within Intent from Understanding Success Criterion 3.2.4 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.2.4 The intent of this Success Criterion is to ensure consistent identification of functional components that appear repeatedly within a set of Web pages. A strategy that people who use screen readers use when operating a Web site is to rely heavily on their familiarity with functions that may appear on different Web pages. If identical functions have different labels on different Web pages, the site will be considerably more difficult to use. It may also be confusing and increase the cognitive load for people with cognitive limitations. Therefore, consistent labeling will help. This consistency extends to the text alternatives. If icons or other non-text items have the same functionality, then their text alternatives should be consistent as well. If there are two components on a web page that both have the same functionality as a component on another page in a set of web pages, then all 3 must be consistent. Hence the two on the same page will be consistent. While it is desirable and best practice always to be consistent within a single web page, 3.2.4 only addresses consistency within a set of web pages where something is repeated on more than one page in the set. Specific Benefits of Success Criterion 3.2.4 People who learn functionality on one page on a site can find the desired functions on other pages if they are present. When non-text content is used in a consistent way to identify components with the same functionality, people with difficulty reading text or detecting text alternatives can interact with the Web without depending on text alternatives. People who depend on text alternatives can have a more predictable experience. They can also search for the component if it has a consistent label on different pages. Guideline 3.3: Input Assistance From Guideline 3.3 Help users avoid and correct mistakes. Additional Guidance When Applying Guideline 3.3 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 3.3 applies directly as written. Intent from Understanding Guideline 3.3 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 3.3 Everyone makes mistakes. However, people with some disabilities have more difficulty creating error-free input. In addition, it may be harder for them to detect that they have made an error. Typical error indication methods may not be obvious to them because of a limited field of view, limited color perception, or use of assistive technology. This guideline seeks to reduce the number of serious or irreversible errors that are made, increase the likelihood that all errors will be noticed by the user, and help users understand what they should do to correct an error. Success Criterion 3.3.1: Error Identification (Level A) From Success Criterion 3.3.1 If an input error Additional Guidance When Applying Success Criterion 3.3.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 3.3.1 Note: Closed Functionality Intent from Understanding Success Criterion 3.3.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.3.1 The intent of this Success Criterion is to ensure that users are aware that an error has occurred and can determine what is wrong. The error message should be as specific as possible. In the case of an unsuccessful form submission, re-displaying the form and indicating the fields in error is insufficient for some users to perceive that an error has occurred. Screen reader users, for example, will not know there was an error until they encounter one of the indicators. They may abandon the form altogether before encountering the error indicator, thinking that the page simply is not functional. Per the definition in WCAG 2.0, an "input error" is information provided by the user that is not accepted. This includes: information that is required by the web page but omitted by the user, or information that is provided by the user but that falls outside the required data format or allowed values. For example: the user fails to enter the proper abbreviation in to state, province, region, etc. field; the user enters a state abbreviation that is not a valid state; the user enters a non existent zip or postal code; the user enters a birth date 2 years in the future; the user enters alphabetic characters or parentheses into their phone number field that only accepts numbers; the user enters a bid that is below the previous bid or the minimum bid increment. Note: Success Criterion 3.3.3 (Error Suggestion) The identification and description of an error can be combined with programmatic information that user agents or assistive technologies can use to identify an error and provide error information to the user. For example, certain technologies can specify that the user's input must not fall outside a specific range, or that a form field is required. Currently, few technologies support this kind of programmatic information, but the Success Criterion does not require, nor prevent it. It is perfectly acceptable to indicate the error in other ways such as image, color etc, in addition to the text description. See also Understanding Success Criterion 3.3.3 Error Suggestion Specific Benefits of Success Criterion 3.3.1 Providing information about input errors in text allows users who are blind or colorblind to perceive the fact that an error occurred. This Success Criterion may help people with cognitive, language, and learning disabilities who have difficulty understanding the meaning represented by icons and other visual cues. Success Criterion 3.3.2: Labels or Instructions (Level A) From Success Criterion 3.3.2 Labels Additional Guidance When Applying Success Criterion 3.3.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 3.3.2 Intent from Understanding Success Criterion 3.3.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.3.2 The intent of this success criterion is to have content authors place instructions or labels that identify the controls in a form so that users know what input data is expected. Instructions or labels may also specify data formats for fields especially if they are out of the customary formats or if there are specific rules for correct input. Content authors may also choose to make such instructions available to users only when the individual control has focus especially when instructions are long and verbose. The intent of this Success Criterion is not to clutter the page with unnecessary information but to provide important cues and instructions that will benefit people with disabilities. Too much information or instruction can be just as much of a hindrance as too little. The goal is to make certain that enough information is provided for the user to accomplish the task without undue confusion or navigation. Note: Understanding Success Criterion 1.3.1 Info and Relationships Specific Benefits of Success Criterion 3.3.2 When label elements are associated with input elements the label is spoken by screen readers when the field receives focus and users with impaired motor control are helped by a larger clickable area for the control, since clicking on the label or the control will activate the control. Field labels located in close proximity to the associated field assist users of screen magnifiers because the field and label are more likely to visible within the magnified area of the page. Providing examples of expected data formats help users with cognitive, language and learning disabilities to enter information correctly. Clearly identifying required fields prevents a keyboard only user from submitting an incomplete form and having to navigate the redisplayed form to find the uncompleted field and provide the missing information. Success Criterion 3.3.3: Error Suggestion (Level AA) From Success Criterion 3.3.3 If an input error Additional Guidance When Applying Success Criterion 3.3.3 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 3.3.3 Intent from Understanding Success Criterion 3.3.3 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.3.3 The intent of this Success Criterion is to ensure that users receive appropriate suggestions for correction of an input error if it is possible. The WCAG 2.0 definition of "input error" says that it is "information provided by the user that is not accepted" by the system. Some examples of information that is not accepted include information that is required but omitted by the user and information that is provided by the user but that falls outside the required data format or allowed values. Success Criterion 3.3.1 provides for notification of errors. However, persons with cognitive limitations may find it difficult to understand how to correct the errors. People with visual disabilities may not be able to figure out exactly how to correct the error. In the case of an unsuccessful form submission, users may abandon the form because they may be unsure of how to correct the error even though they are aware that it has occurred. The content author may provide the description of the error, or the user agent may provide the description of the error based on technology-specific, programmatically determined information. Specific Benefits of Success Criterion 3.3.3 Providing information about how to correct input errors allows users who have learning disabilities to fill in a form successfully. Users who are blind or have impaired vision understand more easily the nature of the input error and how to correct it. People with motion impairment can reduce the number of times they need to change an input value. Success Criterion 3.3.4: Error Prevention (Legal, Financial, Data) (Level AA) From Success Criterion 3.3.4 For Web pages legal commitments user-controllable Reversible: Checked: input errors Confirmed: mechanism Additional Guidance When Applying Success Criterion 3.3.4 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 3.3.4 With this substitution, it would read: 3.3.4 Error Prevention (Legal, Financial, Data): non-web documents software legal commitments user-controllable Reversible: Checked: input errors Confirmed: mechanism Intent from Understanding Success Criterion 3.3.4 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 3.3.4 The intent of this Success Criterion is to help users with disabilities avoid serious consequences as the result of a mistake when performing an action that cannot be reversed. For example, purchasing non-refundable airline tickets or submitting an order to purchase stock in a brokerage account are financial transactions with serious consequences. If a user has made a mistake on the date of air travel, he or she could end up with a ticket for the wrong day that cannot be exchanged. If the user made a mistake on the number of stock shares to be purchased, he or she could end up purchasing more stock than intended. Both of these types of mistakes involve transactions that take place immediately and cannot be altered afterwards, and can be very costly. Likewise, it may be an unrecoverable error if users unintentionally modify or delete data stored in a database that they later need to access, such as their entire travel profile in a travel services web site. When referring to modification or deletion of 'user controllable' data, the intent is to prevent mass loss of data such as deleting a file or record. It is not the intent to require a confirmation for each save command or the simple creation or editing of documents, records or other data. Users with disabilities may be more likely to make mistakes. People with reading disabilities may transpose numbers and letters, and those with motor disabilities may hit keys by mistake. Providing the ability to reverse actions allows users to correct a mistake that could result in serious consequences. Providing the ability to review and correct information gives the user an opportunity to detect a mistake before taking an action that has serious consequences. User-controllable data is user-viewable data that the user can change and/or delete through an intentional action. Examples of the user controlling such data would be updating the phone number and address for the user's account, or deleting a record of past invoices from a website. It does not refer such things as internet logs and search engine monitoring data that the user can't view or interact with directly. Specific Benefits of Success Criterion 3.3.4 Providing safeguards to avoid serious consequences resulting from mistakes helps users with all disabilities who may be more likely to make mistakes. Principle 4: Robust From Principle 4 Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies. Additional Guidance When Applying Principle 4 to Non-Web Documents and Software: In WCAG 2.0, the Principles are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Principle 4 applies directly as written replacing “user agents, including assistive technologies” with “assistive technologies and accessibility features of software”. With this substitution, it would read: Principle 4: Robust - Content must be robust enough that it can be interpreted reliably by a wide variety of assistive technologies Guideline 4.1: Compatible From Guideline 4.1 Maximize compatibility with current and future user agents, including assistive technologies. Additional Guidance When Applying Guideline 4.1 to Non-Web Documents and Software: In WCAG 2.0, the Guidelines are provided for framing and understanding the success criteria under them but are not required for conformance to WCAG. Guideline 4.1 applies directly as written, replacing “user agents, including assistive technologies” with “assistive technologies and accessibility features of software”. With this substitution, it would read: Guideline 4.1 Compatible: Maximize compatibility with current and future assistive technologies Intent from Understanding Guideline 4.1 in Understanding WCAG 2.0 View collapsible version of guidance for Guideline 4.1 The purpose of this guideline is to support compatibility with current and future user agents, especially Success Criterion 4.1.1: Parsing (Level A) From Success Criterion 4.1.1 In content implemented using markup languages, elements have complete start and end tags, elements are nested according to their specifications, elements do not contain duplicate attributes, and any IDs are unique, except where the specifications allow these features. Note: Additional Guidance When Applying Success Criterion 4.1.1 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 4.1.1 With these substitutions, it would read: 4.1.1 Parsing: For non-web documents software assistive technologies user agent Note: Note: assistive technologies user agents Examples of markup that is separately exposed and available to assistive technologies user agents Examples of markup used internally for persistence of the software user interface that are never exposed to assistive technology Note: Closed Functionality Intent from Understanding Success Criterion 4.1.1 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 4.1.1 The intent of this Success Criterion is to ensure that user agents, including assistive technologies, can accurately interpret and parse content. If the content cannot be parsed into a data structure, then different user agents may present it differently or be completely unable to parse it. Some user agents use "repair techniques" to render poorly coded content. Since repair techniques vary among user agents, authors cannot assume that content will be accurately parsed into a data structure or that it will be rendered correctly by specialized user agents, including assistive technologies, unless the content is created according to the rules defined in the formal grammar for that technology. In markup languages, errors in element and attribute syntax and failure to provide properly nested start/end tags lead to errors that prevent user agents from parsing the content reliably. Therefore, the Success Criterion requires that the content can be parsed using only the rules of the formal grammar. Note 1: Note 2: Understanding Success Criterion 1.4.4 Resize text Specific Benefits of Success Criterion 4.1.1 Ensuring that Web pages have complete start and end tags and are nested according to specification helps ensure that assistive technologies can parse the content accurately and without crashing. Success Criterion 4.1.2: Name, Role, Value (Level A) From Success Criterion 4.1.2 For all user interface components name role programmatically determined programmatically set user agents assistive technologies Note: Additional Guidance When Applying Success Criterion 4.1.2 to Non-Web Documents and Software: This applies directly as written, and as described in Intent from Understanding Success Criterion 4.1.2 With this substitution, it would read: 4.1.2 Name, Role, Value: user interface components name role programmatically determined programmatically set user agents assistive technologies Note: This success criterion is primarily for software developers who develop or use custom user interface components. Standard user interface components on most accessibility-supported Note 1: Note 2: Note 3: Closed Functionality Intent from Understanding Success Criterion 4.1.2 in Understanding WCAG 2.0 View collapsible version of guidance for Success Criterion 4.1.2 The intent of this Success Criterion is to ensure that Assistive Technologies (AT) can gather information about, activate(or set) and keep up to date on the status of user interface controls in the content. When standard controls from accessible technologies are used, this process is straightforward. If the user interface elements are used according to specification the conditions of this provision will be met. (See examples of Success Criterion 4.1.2 below) If custom controls are created, however, or interface elements are programmed (in code or script) to have a different role and/or function than usual, then additional measures need to be taken to ensure that the controls provide important information to assistive technologies and allow themselves to be controlled by assistive technologies. A particularly important state of a user interface control is whether or not it has focus. The focus state of a control can be programmatically determined, and notifications about change of focus are sent to user agents and assistive technology. Other examples of user interface control state are whether or not a checkbox or radio button has been selected, or whether or not a collapsible tree or list node is expanded or collapsed. Note: Specific Benefits of Success Criterion 4.1.2 Providing role, state, and value information on all user interface components enables compatibility with assistive technology, such as screen readers, screen magnifiers, and speech recognition software, used by people with disabilities. 7. The following is a complete list of definitions from the WCAG 2.0 glossary. Some items apply to all technologies and do not require additional guidance in this document; guidance on the remainder follows. 7.1. The following glossary items apply to all technologies and do not require further interpretation for non-web Information and Communications Technologies. abbreviation alternative to time-based media ASCII art audio audio description audio-only blinking CAPTCHA captions correct reading sequence emergency essential extended audio description flash functionality human language idiom image of text informative jargon large scale (text) legal commitments link purpose live lower secondary education level mechanism media alternative for text navigated sequentially non-text content normative on a full-screen window paused prerecorded presentation primary education level programatically determined link context pure decoration real-time event relationships relied upon (technologies that are) same relative order sign language sign language interpretation specific sensory experience synchronized media text text alternative used in an unusual or restricted way user-controllable video video-only visually customized 7.2. This document does not provide guidance on applying AAA Success Criteria to non-web ICT, including the following definitions. blocks of text context sensitive help section supplemental content 7.3. Additional guidance is provided for the following glossary entries from WCAG 2.0 when applying them to non-web documents and software. accessibility supported From the WCAG 2.0 definition for accessibility supported supported by users' assistive technologies user agents To qualify as an accessibility-supported use of a Web content technology (or feature of a technology), both 1 and 2 must be satisfied for a Web content technology (or feature): The way that the Web content technology human language(s) AND The Web content technology must have accessibility-supported user agents that are available to users. The technology is supported natively in widely-distributed user agents that are also accessibility supported (such as HTML and CSS); OR The technology is supported in a widely-distributed plug-in that is also accessibility supported; OR The content is available in a closed environment, such as a university or corporate network, where the user agent required by the technology and used by the organization is also accessibility supported; OR The user agent(s) that support the technology are accessibility supported and are available for download or purchase in a way that: does not cost a person with a disability any more than a person without a disability and is as easy to find and obtain for a person with a disability as it is for a person without disabilities. Note 1: Level of Assistive Technology Support Needed for "Accessibility Support" Note 2: relied upon Conformance Requirement 4: Only Accessibility-Supported Ways of Using Technologies Conformance Requirement 5: Non-Interference Note 3: Web Technology Note 4: Note 5: Understanding Accessibility-Supported Web Technology Uses Additional Guidance When Applying the Definition of “accessibility supported” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “browsers and other user agents” with “user agents or other software”, replacing “user agents” with “user agents or other software”, replacing “web content technology” with “non-web document or software technology”, adding “or other software extension” after “plug-in”, and replacing all five of the Notes with a single new Note: “Note: The concepts behind the five Notes and in Understanding Accessibility Supported are applicable to web technologies. The same or similar factors are applicable for non-web technologies.” With these substitutions and addition, it would read: accessibility supported supported by users' assistive technologies user agents software To qualify as an accessibility-supported use of a non-web document software technology non-web document software technology The way that the non-web document software technology human language(s) content AND The non-web document software technology or other software The technology or other software OR The technology or other software extension OR The content or other software OR The user agent(s) that support the technology does not cost a person with a disability any more than a person without a disability and is as easy to find and obtain for a person with a disability as it is for a person without disabilities. Note: Understanding Accessibility Supported ambiguous to users in general From the WCAG 2.0 definition for ambiguous to users in general the purpose cannot be determined from the link and all information of the Web page presented to the user simultaneously with the link (i.e., readers without disabilities would not know what a link would do until they activated it) Example: Additional Guidance When Applying the Definition of “ambiguous to users in general” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “Web page” with “non-web document or software”. With this substitution, it would read: ambiguous to users in general the purpose cannot be determined from the link and all information of the non-web document software Example: assistive technology (as used in this document) From the WCAG 2.0 definition for assistive technology (as used in this document) hardware and/or software that acts as a user agent Note 1: Note 2: APIs Note 3: Example: screen magnifiers, and other visual reading assistants, which are used by people with visual, perceptual and physical print disabilities to change text font, size, spacing, color, synchronization with speech, etc. in order to improve the visual readability of rendered text and images; screen readers, which are used by people who are blind to read textual information through synthesized speech or braille; text-to-speech software, which is used by some people with cognitive, language, and learning disabilities to convert text into synthetic speech; speech recognition software, which may be used by people who have some physical disabilities; alternative keyboards, which are used by people with certain physical disabilities to simulate the keyboard (including alternate keyboards that use head pointers, single switches, sip/puff and other special input devices.); alternative pointing devices, which are used by people with certain physical disabilities to simulate mouse pointing and button activations. Additional Guidance When Applying the Definition of “assistive technology (as used in this document)” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “acts as a user agent” with “acts stand-alone”, replacing “mainstream user agent[s]” with “mainstream information and communication technologies (ICT)” (later “mainstream ICT[s])”, and replacing “Web content” with “content”. With these substitutions, it would read: assistive technology (as used in this document) hardware and/or software that acts stand-alone mainstream information and communication technologies (ICT) mainstream ICT Note 1: Note 2: mainstream ICTs APIs Note 3: mainstream ICTs mainstream ICTs mainstream ICTs mainstream ICT content Example: screen magnifiers, and other visual reading assistants, which are used by people with visual, perceptual and physical print disabilities to change text font, size, spacing, color, synchronization with speech, etc. in order to improve the visual readability of rendered text and images; screen readers, which are used by people who are blind to read textual information through synthesized speech or braille; text-to-speech software, which is used by some people with cognitive, language, and learning disabilities to convert text into synthetic speech; speech recognition software, which may be used by people who have some physical disabilities; alternative keyboards, which are used by people with certain physical disabilities to simulate the keyboard (including alternate keyboards that use head pointers, single switches, sip/puff and other special input devices.); alternative pointing devices, which are used by people with certain physical disabilities to simulate mouse pointing and button activations. changes of context From the WCAG 2.0 definition for changes of context major changes in the content of the Web page Changes in context include changes of: user agent viewport focus; content Web page Note: Example: Additional Guidance When Applying the Definition of “changes of context” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “Web page” and “page” with “non-web document or content presented by software”. With this substitution, it would read: changes of context major changes in the content of the non-web document content software non-web document content software Changes in context include changes of: user agent viewport focus; content non-web document content software Note: content Example: Note: conformance From the WCAG 2.0 definition for conformance satisfying all the requirements of a given standard, guideline or specification Additional Guidance When Applying the Definition of “conformance” to Non-Web Documents and Software: The guidance in this document does not use the term “conformance”. See Section 6 Comments on Conformance conforming alternate version From the WCAG 2.0 definition for conforming alternate version version that conforms at the designated level, and provides all of the same information and functionality human language is as up to date as the non-conforming content, and for which at least one of the following is true: the conforming version can be reached from the non-conforming page via an accessibility-supported mechanism the non-conforming version can only be reached from the conforming version, or the non-conforming version can only be reached from a conforming page that also provides a mechanism to reach the conforming version Note 1: Note 2: Note 3: Note 4: conformance requirement 1 Note 5: Note 6: supplementary content Note 7: Additional Guidance When Applying the Definition of “conforming alternate version” to Non-Web Documents and Software: The guidance in this document does not use the term “conforming alternate version”. See Section 6 Coments on Conformance content (Web content) From the WCAG 2.0 definition for content (Web content) information and sensory experience to be communicated to the user by means of a user agent structure presentation Additional Guidance When Applying the Definition of “content (Web content)” to Non-Web Documents and Software: See the guidance on content in the Key Terms section contrast ratio From the WCAG 2.0 definition for contrast ratio (L1 + 0.05) / (L2 + 0.05), where L1 is the relative luminance L2 is the relative luminance Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Additional Guidance When Applying the Definition of “contrast ratio” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary. Because relative luminance is defined such that it cannot directly apply to hardware, please note the text in the introduction which reads: “This document does not comment on hardware aspects of products, non-UI aspects of platforms, or the application of WCAG 2.0 for user-interface components as a category, because the basic constructs on which the WCAG 2.0 and / or its conformance are built do not apply to these.” general flash and red flash thresholds From the WCAG 2.0 definition for general flash and red flash thresholds a flash passes there are no more than three general flashes red flashes the combined area of flashes occurring concurrently occupies no more than a total of .006 steradians within any 10 degree visual field on the screen (25% of any 10 degree visual field on the screen) at typical viewing distance where: A general flash relative luminance A red flash Exception: Note 1: Note 2: Note 3: "pair of opposing transitions involving a saturated red" [HARDING-BINNIE] Note 4: Additional Guidance When Applying the Definition of “general flash and red flash thresholds” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary. Note: input error From the WCAG 2.0 definition for input error information provided by the user that is not accepted Note: Information that is required by the Web page Information that is provided by the user but that falls outside the required data format or values Additional Guidance When Applying the Definition of “input error” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “Web page” with “non-web document or software”. With this substitution, it would read: input error information provided by the user that is not accepted Note: Information that is required by the non-web document software Information that is provided by the user but that falls outside the required data format or values keyboard interface From the WCAG 2.0 definition for keyboard interface interface used by software to obtain keystroke input Note 1: Example: Note 2: Additional Guidance When Applying the Definition of “keyboard interface” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary. Please see the note in the guidance for Success Criterion 2.1.1 label From the WCAG 2.0 definition for label text text alternative content Note 1: name Note 2: Additional Guidance When Applying the Definition of “label” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “Web Content” with “content” and adding “or by accessibility features of software” after “assistive technology” in Note 1. With this substitution, it would read: label text text alternative content Note 1: name or by accessibility features of software Note 2: name From the WCAG 2.0 definition for name text by which software can identify a component within Web content to the user Note 1: label Note 2: Additional Guidance When Applying the Definition of “name” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “Web content” with “content” and adding “or by accessibility features of software” after “assistive technology” in Note 1. With this substitution, it would read: name text by which software can identify a component within content Note 1: or by accessibility features of software label Note 2: Note: process From the WCAG 2.0 definition for process series of user actions where each action is required in order to complete an activity Example 1: Example 2: Additional Guidance When Applying the Definition of “process” to Non-Web Documents and Software: This term is only used in success criterion 2.4.5 Multiple Ways set of documents set of software programs 2.4.5 Multiple Ways set of documents set of software programs programmatically determined (programmatically determinable) From the WCAG 2.0 definition for programmatically determined (programmatically determinable) determined by software from author-supplied data provided in a way that different user agents assistive technologies Example 1: Example 2: API Additional Guidance When Applying the Definition of “programmatically determined (programmatically determinable)” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “user agents, including assistive technologies” with “assistive technologies and accessibility features of software” and adding and “accessibility features of software” after “assistive technology”. With this substitution, it would read: programmatically determined (programmatically determinable) determined by software assistive technologies Example 1: and accessibility features of software Example 2: and accessibility features of software API and accessibility features of software Note: accessibility services of platform software content programmatically set From the WCAG 2.0 definition for programmatically set set by software using methods that are supported by user agents, including assistive technologies Additional Guidance When Applying the Definition of “programmatically set” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “user agents, including assistive technologies” with “assistive technologies and accessibility features of software”. With this substitution, it would read: programmatically set set by software using methods that are supported by assistive technologies Note: content accessibility services of platform software relative luminance From the WCAG 2.0 definition for relative luminance the relative brightness of any point in a colorspace, normalized to 0 for darkest black and 1 for lightest white Note 1: R G B R G B if R sRGB R sRGB R sRGB if G sRGB G sRGB G sRGB if B sRGB B sRGB B sRGB and R sRGB sRGB sRGB R sRGB 8bit G sRGB 8bit B sRGB 8bit The "^" character is the exponentiation operator. (Formula taken from [sRGB] [IEC-4WD] Note 2: Understanding Success Criterion 1.4.3 Note 3: Note 4: Note 5: MathML version of the relative luminance definition Additional Guidance When Applying the Definition of “relative luminance” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “Web content” with “content”. With this substitution, it would read: relative luminance the relative brightness of any point in a colorspace, normalized to 0 for darkest black and 1 for lightest white Note 1: R G B R G B if R sRGB R sRGB R sRGB if G sRGB G sRGB G sRGB if B sRGB B sRGB B sRGB and R sRGB sRGB sRGB R sRGB 8bit G sRGB 8bit B sRGB 8bit The “^” character is the exponentiation operator. (Formula taken from [sRGB] [IEC-4WD] Note 2: content Understanding Success Criterion 1.4.3 Note 3: Note 4: Note 5: MathML version of the relative luminance definition Because relative luminance is defined such that it cannot directly apply to hardware, please note the text in the introduction which reads: “This document does not comment on hardware aspects of products, non-UI aspects of platforms, or the application of WCAG 2.0 for user-interface components as a category, because the basic constructs on which the WCAG 2.0 and / or its conformance are built do not apply to these.” role From the WCAG 2.0 definition for role text or number by which software can identify the function of a component within Web content Example: Additional Guidance When Applying the Definition of “role” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “Web content” with “content”. With this substitution, it would read: role text or number by which software can identify the function of a component within content Example: Note: same functionality From the WCAG 2.0 definition for same functionality same result when used Example: Additional Guidance When Applying the Definition of “same functionality ” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, adding a second example (and numbering the first). With these substitutions, it would read: same functionality same result when used Example 1 Example 2: satisfies a success criterion From the WCAG 2.0 definition for satisfies a success criterion the success criterion does not evaluate to 'false' when applied to the page Additional Guidance When Applying the Definition of “satisfies a success criterion” to Non-Web Documents and Software: The guidance in this document does not use the term “satisfies a success criterion”. See Section 6 Comments on Conformance set of Web pages From the WCAG 2.0 definition for set of Web pages collection of Web pages Note: Additional Guidance When Applying the Definition of “set of Web pages” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary. Note: 2.4.1 2.4.5 3.2.3 3.2.4 structure From the WCAG 2.0 definition for structure The way the parts of a Web page The way a collection of Web pages Additional Guidance When Applying the Definition of “structure” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “a Web page” with “non-web documents or software” and replacing “collection of Web pages” with “set of documents or set of software programs”. With these substitutions, it would read: structure The way the parts of non-web documents software The way a set of documents set of software programs Note 1: sets of documents sets of software programs Note 2: technology (Web content) From the WCAG 2.0 definition for technology (Web content) mechanism user agents Note 1: Note 2: Example: HTML CSS SVG PNG PDF Additional Guidance When Applying the Definition of “technology (Web content)” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “web content” with “non-web document or software”, “user agents” with “user agents or other software”, removing the notes, and replacing the example with “Example: Some common examples of non-web document and software technologies include ODF, OOXML, Java, and C++.” With these substitutions, it would read: technology ( non-web document or software mechanism user agents software Example: non-web document and software technologies include ODF, OOXML, Java, and C++ user agent From the WCAG 2.0 definition for user agent any software that retrieves and presents Web content for users Example: assistive technologies Additional Guidance When Applying the Definition of “user agent” to Non-Web Documents and Software: See the guidance on user agent in the Key Terms section user interface component From the WCAG 2.0 definition for user interface component a part of the content that is perceived by users as a single control for a distinct function Note 1: Note 2: Example: Additional Guidance When Applying the Definition of “user interface component” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing the example with “Example: A software program has 2 controls: a text field for entering a file name and a drop down list box for choosing a folder. Each is a user interface component with a name that is settable by the software.” With this substitution, it would read: user interface component a part of the content Note 1: Note 2: Example: A software software viewport From the WCAG 2.0 definition for viewport object in which the user agent presents content Note 1: user agent Note 2: User Agent Accessibility Guidelines 1.0 Glossary Additional Guidance When Applying the Definition of “viewport” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary, replacing “user agent” with “software”. With this substitution, it would read: viewport object in which the software content Note 1: software content software Note 2: User Agent Accessibility Guidelines 1.0 Glossary Web page From the WCAG 2.0 definition for Web page a non-embedded resource obtained from a single URI using HTTP plus any other resources that are used in the rendering or intended to be rendered together with it by a user agent Note 1: Note 2: Example 1: Example 2: Example 3: Example 4: Additional Guidance When Applying the Definition of “Web page” to Non-Web Documents and Software: This applies directly as written and as described in the WCAG 2.0 glossary. Note: Appendix A. The following success criteria will be problematic for developers of closed functionality. They either discuss making information available in text (which can be read by assistive technologies) or making it “programmatically determinable” (rendered by a user agent and readable by assistive technologies) or discuss doing something else to make content compatible with assistive technologies. Alternate accessibility provisions that would be needed to address the purpose of these success criteria for the closed functionality aspects of products: 1.1.1 Non-text Content 1.2.1 Pre-recorded video 1.2.3 Audio description or Media Alternative 1.3.1 Info and Relationships 1.3.2 Meaningful Sequence 1.4.4 Resize Text 1.4.5 Images of Text 2.1.1 Keyboard 2.4.2 Page Titled 3.1.1 Language of Page 3.1.2 Language of Parts 3.3.1 Error Identification 4.1.1 Parsing Intent of 4.1.1 4.1.2 Name, Role, Value Note 1: Note 2: Appendix B. Appendix B.1. The interface of a text application is realized through a text application directing which characters should be placed on the screen, along with either a hardware terminal or a terminal application that displays the characters produced by the text application. Some text applications render like a TeleTYpewriter (“TTY”); their output is always appended, like an ever growing file. Such text applications are often called “command-line applications” or occasionally “TTY-applications”, and their output can optionally be redirected to a file for later review. Others explicitly place text into a matrix of fixed width character cells on a screen (sometimes with specific foreground and background colors). Similar to a web application, the text application may execute primarily on a remote server or execute locally, and a local client terminal application handles the visual display (similar to a web user agent). Input to the text application itself is provided exclusively through a keyboard interface. Appendix B.2. Strategies for making text applications accessible through assistive technology involve two key tasks: (1) obtaining all of the text displayed in the interface, and (2) performing an analysis on that text to discern structural elements and screen updates. For example, a text application screen reader might directly access the matrix of character cells in the interface and provide a screen review mechanism for the user to review that matrix of characters (by sending the output to synthetic speech and / or a braille display). Alternately, a text application screen reader might directly consume the output rendered (perhaps by acting as its own terminal application or by analyzing the “TTY” output). The text application screen reader would also analyze the spacing and layout of the text in the matrix to provide features such as reading columns of text in a multi-column layout, discerning headers through analysis of line spacing, indentation and capitalization, and discerning input fields or user interface components, etc. by scanning for the use of inverse video or for text appearing in brackets or text from the character graphics codepage (ASCII codes greater than ‘0x7F’). Some of this analysis might also be done through the use of filter tools that transform the output of a program (e.g. through reformatting “TTY” output rendered to a file or as direct input to a filter too). Similarly, a text application screen magnifier would gain access to the matrix of character cells in order to magnify them or re-display them in a larger font. It would scan for screen refreshes / updates and apply heuristics to what had changed in order to decide what sub-matrix of character cells should appear in a magnified view. It would also scan for inverse video and a moving text cursor to track text being input by the user (and might combine the text matrix scanning with scanning of the keyboard input to match user input to what is appearing on the screen). Appendix B.3. To apply WCAG to text applications, it is necessary to apply the glossary terms “accessibility supported” and “programmatically determined” in the context of how text applications are rendered and the history of assistive technologies that made them accessible. As noted above, in a text interface the terminal application renders the characters on the screen, just as a web browser typically renders content for a web application. Thus for example, in success criterion 1.4.4 Resize Text G142 Using a technology that has commonly-available user agents that support zoom 1.4.4 Resize Text A similar approach could also be used for success criterion 1.4.3 Contrast (minimum) G148: Not specifying background color, not specifying text color, and not using technology features that change those defaults Since many assistive technology analysis techniques depend upon discerning the location of the text input cursor, terminal application use of “soft cursors” and “highlight bars” may bypass those analysis techniques and cause failures of success criteria. Note: The way to think about “ accessibility supported programmatically determined Note: Appendix C. Appendix C.1. The following people were active participants in the WCAG2ICT Task Force Shadi Abou-Zahra, W3C Bruce Bailey, Invited Expert, US Access Board Judy Brewer, W3C Michael Cooper, W3C Pierce Crowell, Invited Expert, US Social Security Administration Allen Hoffman, Invited Expert, US Department of Homeland Security Kiran Kaja, Adobe Systems Inc. Andrew Kirkpatrick, Adobe Systems Inc. Peter Korn, Oracle Corporation Alex Li, Microsoft Corporation David MacDonald, Invited Expert Loïc Martínez Normand, Universidad Politécnica de Madrid Mary Jo Mueller, IBM Corporation Mike Pluke, Invited Expert Janina Sajka, Invited Expert Andi Snow-Weaver, IBM Corporation Gregg Vanderheiden, Invited Expert, Trace Research and Development Center Appendix C.2. The following people were active participants in the Web Content Accessibility Guidelines Working Group Bruce Bailey, Invited Expert, US Access Board Tim Boland, NIST Judy Brewer, W3C Michael Cooper, W3C Cherie Ekholm, Microsoft Corporation Detlev Fischer, Invited Expert Loretta Guarino Reid, Google, Inc. Jon Gunderson, Invited Expert, Illinois Center for Information Technology and Web Accessibility Katie Haritos-Shea, Invited Expert Marc Johlic, IBM Andrew Kirkpatrick, Adobe Systems Inc. Peter Korn, Oracle Corporation Maureen Kraft, IBM Corporation Alex Li, Microsoft Corporation David MacDonald, Invited Expert James Nurthen, Oracle Corporation Joshue O Connor, Invited Expert, NCBI Centre for Inclusive Technology Andi Snow-Weaver, IBM Corporation Adam Solomon, Invited Expert Robin Tuttle, The Boeing Company Gregg Vanderheiden, Invited Expert, Trace Research and Development Center Kathleen Wahlbin, Invited Expert Gian Wild, AccessibiltyOz Appendix C.3. This publication has been funded in part with Federal funds from the U.S. Department of Education, National Institute on Disability and Rehabilitation Research (NIDRR) under contract number ED-OSE-10-C-0067. The content of this publication does not necessarily reflect the views or policies of the U.S. Department of Education, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. Appendix D. UNDERSTANDING-WCAG20 Understanding WCAG 2.0 Latest version WCAG20 Web Content Accessibility Guidelines (WCAG) 2.0 Latest version WCAG20-TECHS Techniques for WCAG 2.0 Latest version

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