WCAG-Kriterien und zusätzliche EU-Kriterien

Die EU-Richtlinie über den barrierefreien Zugang zu den Websites und mobilen Anwendungen öffentlicher Stellen gibt vor welche Kriterien erfüllt sein müssen, damit eine Website oder mobile Anwendung als barrierefrei eingestuft werden kann. Diese Kriterien sind in der Norm „Accessibility requirements for ICT products and services“ (EN 301 549) angeführt. Aktuell gilt noch die Version 2.1.1 (2018-08) der Norm. Diese Version referenziert im Prinzip auf die Web Content Accessibility Guidelines (WCAG) in der Fassung 2.1 A bzw. AA.

Ab dem 12.02.2022 gilt die Version 3.2.1 (2021-03) der Norm. Da beim Studium dieser neuen Version der Norm vielleicht nicht auf den ersten Blick klar ist, welche Kriterien nun tatsächlich erfüllt werden sollen, haben wir diese hier zusammengefasst.

Ein Großteil der Klauseln in der Norm, die mit den Nummern 9 (bezieht sich auf Web), 10 (bezieht sich auf Dokumente) und 11 (bezieht sich auf Software, bspw. mobile Anwendungen) beginnen sind ident mit den Kriterien der Web Content Accessibility Guidelines (WCAG) in der Fassung 2.1 A bzw. AA; diese werden hier zuerst angeführt. Zusätzlich dazu gelten weitere Kriterien abseits der WCAG 2.1, die wir im Bereich „Additional EU-Criteria EN 301 549 V3.2.1“ aufgelistet haben.

Die meisten dieser weiteren Kriterien der Norm müssen nur unter bestimmten Voraussetzungen erfüllt werden. Die jeweilige Voraussetzung ist im Kriterientext unter "Condition" zu finden.

 

Information and user interface components must be presentable to users in ways they can perceive.

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.

All non-text content that is presented to the user has a text alternative that serves the equivalent purpose, except for the situations listed below.

Controls, Input: If non-text content is a control or accepts user input, then it has a name that describes its purpose. (Refer to Success Criterion 4.1.2 for additional requirements for controls and content that accepts user input.)

Time-Based Media: If non-text content is time-based media, then text alternatives at least provide descriptive identification of the non-text content. (Refer to Guideline 1.2 for additional requirements for media.)

Test: If non-text content is a test or exercise that would be invalid if presented in text, then text alternatives at least provide descriptive identification of the non-text content.

Sensory: If non-text content is primarily intended to create a specific sensory experience, then text alternatives at least provide descriptive identification of the non-text content.

CAPTCHA: If the purpose of non-text content is to confirm that content is being accessed by a person rather than a computer, then text alternatives that identify and describe the purpose of the non-text content are provided, and alternative forms of CAPTCHA using output modes for different types of sensory perception are provided to accommodate different disabilities.

Decoration, Formatting, Invisible: If non-text content is pure decoration, is used only for visual formatting, or is not presented to users, then it is implemented in a way that it can be ignored by assistive technology.

Provide alternatives for time-based media.

For prerecorded audio-only and prerecorded video-only media, the following are true, except when the audio or video is a media alternative for text and is clearly labeled as such:

Prerecorded Audio-only: An alternative for time-based media is provided that presents equivalent information for prerecorded audio-only content.

Prerecorded Video-only: Either an alternative for time-based media or an audio track is provided that presents equivalent information for prerecorded video-only content.

Captions are provided for all prerecorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labeled as such.

An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media, except when the media is a media alternative for text and is clearly labeled as such.

Audio description is provided for all prerecorded video content in synchronized media.

Create content that can be presented in different ways (for example simpler layout) without losing information or structure.

Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text.

When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically determined.

Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, color, size, visual location, orientation, or sound.

Note 1: For requirements related to color, refer to Guideline 1.4.

Content does not restrict its view and operation to a single display orientation, such as portrait or landscape, unless a specific display orientation is essential.

The purpose of each input field collecting information about the user can be programmatically determined when:

The input field serves a purpose identified in the Input Purposes for User Interface Components section; and

The content is implemented using technologies with support for identifying the expected meaning for form input data.

Make it easier for users to see and hear content including separating foreground from background.

Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.

Note 1: This success criterion addresses color perception specifically. Other forms of perception are covered in Guideline 1.3 including programmatic access to color and other visual presentation coding.

If any audio on a Web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume independently from the overall system volume level.

Note 1: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether or not it is used to meet other success criteria) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following:

Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 3:1;

Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.

Logotypes: Text that is part of a logo or brand name has no contrast requirement.

Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.

If the technologies being used can achieve the visual presentation, text is used to convey information rather than images of text except for the following:

Customizable: The image of text can be visually customized to the user's requirements;

Essential: A particular presentation of text is essential to the information being conveyed.

Note 1: Logotypes (text that is part of a logo or brand name) are considered essential.

Content can be presented without loss of information or functionality, and without requiring scrolling in two dimensions for:

Vertical scrolling content at a width equivalent to 320 CSS pixels;

Horizontal scrolling content at a height equivalent to 256 CSS pixels;

Except for parts of the content which require two-dimensional layout for usage or meaning.

The visual presentation of the following have a contrast ratio of at least 3:1 against adjacent color(s):

User Interface Components: Visual information required to identify user interface components and states, except for inactive components or where the appearance of the component is determined by the user agent and not modified by the author;

Graphical Objects: Parts of graphics required to understand the content, except when a particular presentation of graphics is essential to the information being conveyed.

In content implemented using markup languages that support the following text style properties, no loss of content or functionality occurs by setting all of the following and by changing no other style property:

Line height (line spacing) to at least 1.5 times the font size;

Spacing following paragraphs to at least 2 times the font size;

Letter spacing (tracking) to at least 0.12 times the font size;

Word spacing to at least 0.16 times the font size.

Exception: Human languages and scripts that do not make use of one or more of these text style properties in written text can conform using only the properties that exist for that combination of language and script.

Where receiving and then removing pointer hover or keyboard focus triggers additional content to become visible and then hidden, the following are true:

Dismissible: A mechanism is available to dismiss the additional content without moving pointer hover or keyboard focus, unless the additional content communicates an input error or does not obscure or replace other content;

Hoverable: If pointer hover can trigger the additional content, then the pointer can be moved over the additional content without the additional content disappearing;

Persistent: The additional content remains visible until the hover or focus trigger is removed, the user dismisses it, or its information is no longer valid.

Exception: The visual presentation of the additional content is controlled by the user agent and is not modified by the author.

User interface components and navigation must be operable.

Make all functionality available from a keyboard.

All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints.

Note 1: This exception relates to the underlying function, not the input technique. For example, if using handwriting to enter text, the input technique (handwriting) requires path-dependent input but the underlying function (text input) does not.

Note 2: This does not forbid and should not discourage providing mouse input or other input methods in addition to keyboard operation.

If keyboard focus can be moved to a component of the page using a keyboard interface, then focus can be moved away from that component using only a keyboard interface, and, if it requires more than unmodified arrow or tab keys or other standard exit methods, the user is advised of the method for moving focus away.

Note 1: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

If a keyboard shortcut is implemented in content using only letter (including upper- and lower-case letters), punctuation, number, or symbol characters, then at least one of the following is true:

Turn off: A mechanism is available to turn the shortcut off;

Remap: A mechanism is available to remap the shortcut to include one or more non-printable keyboard keys (e.g., Ctrl, Alt);

Active only on focus: The keyboard shortcut for a user interface component is only active when that component has focus.

Provide users enough time to read and use content.

For each time limit that is set by the content, at least one of the following is true:

Turn off: The user is allowed to turn off the time limit before encountering it; or

Adjust: The user is allowed to adjust the time limit before encountering it over a wide range that is at least ten times the length of the default setting; or

Extend: The user is warned before time expires and given at least 20 seconds to extend the time limit with a simple action (for example, "press the space bar"), and the user is allowed to extend the time limit at least ten times; or

Real-time Exception: The time limit is a required part of a real-time event (for example, an auction), and no alternative to the time limit is possible; or

Essential Exception: The time limit is essential and extending it would invalidate the activity; or

20 Hour Exception: The time limit is longer than 20 hours.

For moving, blinking, scrolling, or auto-updating information, all of the following are true:

Moving, blinking, scrolling: For any moving, blinking or scrolling information that (1) starts automatically, (2) lasts more than five seconds, and (3) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it unless the movement, blinking, or scrolling is part of an activity where it is essential; and

Auto-updating: For any auto-updating information that (1) starts automatically and (2) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it or to control the frequency of the update unless the auto-updating is part of an activity where it is essential.

Note 1: For requirements related to flickering or flashing content, refer to Guideline 2.3.

Note 2: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

Note 3: Content that is updated periodically by software or that is streamed to the user agent is not required to preserve or present information that is generated or received between the initiation of the pause and resuming presentation, as this may not be technically possible, and in many situations could be misleading to do so.

Note 4: An animation that occurs as part of a preload phase or similar situation can be considered essential if interaction cannot occur during that phase for all users and if not indicating progress could confuse users or cause them to think that content was frozen or broken.

Do not design content in a way that is known to cause seizures or physical reactions.

Web pages do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds.

Note 1: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

Provide ways to help users navigate, find content, and determine where they are.

A mechanism is available to bypass blocks of content that are repeated on multiple Web pages.

Web pages have titles that describe topic or purpose.

If a Web page can be navigated sequentially and the navigation sequences affect meaning or operation, focusable components receive focus in an order that preserves meaning and operability.

The purpose of each link can be determined from the link text alone or from the link text together with its programmatically determined link context, except where the purpose of the link would be ambiguous to users in general.

More than one way is available to locate a Web page within a set of Web pages except where the Web Page is the result of, or a step in, a process.

Headings and labels describe topic or purpose.

Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible.

Make it easier for users to operate functionality through various inputs beyond keyboard.

All functionality that uses multipoint or path-based gestures for operation can be operated with a single pointer without a path-based gesture, unless a multipoint or path-based gesture is essential.

For functionality that can be operated using a single pointer, at least one of the following is true:

No Down-Event: The down-event of the pointer is not used to execute any part of the function;

Abort or Undo: Completion of the function is on the up-event, and a mechanism is available to abort the function before completion or to undo the function after completion;

Up Reversal: The up-event reverses any outcome of the preceding down-event;

Essential: Completing the function on the down-event is essential.

For user interface components with labels that include text or images of text, the name contains the text that is presented visually.

Functionality that can be operated by device motion or user motion can also be operated by user interface components and responding to the motion can be disabled to prevent accidental actuation, except when:

Information and the operation of the user interface must be understandable.

Make text content readable and understandable.

The default human language of each Web page can be programmatically determined.

The human language of each passage or phrase in the content can be programmatically determined except for proper names, technical terms, words of indeterminate language, and words or phrases that have become part of the vernacular of the immediately surrounding text.

Make Web pages appear and operate in predictable ways.

When any user interface component receives focus, it does not initiate a change of context.

Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component.

Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user.

Components that have the same functionality within a set of Web pages are identified consistently.

Help users avoid and correct mistakes.

If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text.

Labels or instructions are provided when content requires user input.

If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content.

For Web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true:

Reversible: Submissions are reversible.

Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.

Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.

Content must be robust enough that it can be interpreted by a wide variety of user agents, including assistive technologies.

Maximize compatibility with current and future user agents, including assistive technologies.

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 1: Start and end tags that are missing a critical character in their formation, such as a closing angle bracket or a mismatched attribute value quotation mark are not complete.

For all user interface components (including but not limited to: form elements, links and components generated by scripts), the name and role can be programmatically determined; states, properties, and values that can be set by the user can be programmatically set; and notification of changes to these items is available to user agents, including assistive technologies.

Note 1: This success criterion is primarily for Web authors who develop or script their own user interface components. For example, standard HTML controls already meet this success criterion when used according to specification.

In content implemented using markup languages, status messages can be programmatically determined through role or properties such that they can be presented to the user by assistive technologies without receiving focus.

Condition: Where web content or ICT has documented accessibility features.

Where ICT has documented accessibility features, it shall be possible to activate those documented accessibility features that are required to meet a specific need without relying on a method that does not support that need.

Condition: Where web content or ICT uses biological characteristics.

Where ICT uses biological characteristics, it shall not rely on the use of a particular biological characteristic as the only means of user identification or for control of ICT

Note: Alternative means of user identification or for control of ICT could be non-biometric or biometric.

Note: Biometric methods based on dissimilar biological characteristics increase the likelihood that individuals with disabilities possess at least one of the specified biological characteristics. Examples of dissimilar biological characteristics are fingerprints, eye retinal patterns, voice, and face.

Condition: Where web content or ICT converts information or communication

Where ICT converts information or communication it shall preserve all documented non-proprietary information that is provided for accessibility, to the extent that such information can be contained in or supported by the destination format.

Condition: Only for mobile applications: Where ICT has operable parts

Where ICT has operable parts that require grasping, pinching, or twisting of the wrist to operate, an accessible alternative means of operation that does not require these actions shall be provided.

Condition: Only for mobile applications: Where ICT has operable parts

Where ICT has operable parts, it shall provide a means to discern each operable part, without requiring vision and without performing the action associated with the operable part.

Note: One way of meeting this requirement is by making the operable parts tactilely discernible.

Condition: Only for mobile applications: Where ICT has a locking or toggle control

Where ICT has a locking or toggle control and the status of that control is visually presented to the user, the ICT shall provide at least one mode of operation where the status of the control can be determined either through touch or sound without operating the control.

Note: Locking or toggle controls are those controls that can only have two or three states and that keep their state while being used.

Note: An example of a locking or toggle control is the "Caps Lock" key found on most keyboards. Another example is the volume button on a pay telephone, which can be set at normal, loud, or extra loud volume.

Condition: Only for mobile applications: Where ICT has a locking or toggle control

Where ICT has a locking or toggle control and the status of the control is non-visually presented to the user, the ICT shall provide at least one mode of operation where the status of the control can be visually determined when the control is presented.

Note: Locking or toggle controls are those controls that can only have two or three states and that keep their state while being used.

Note: An example of a locking or toggle control is the "Caps Lock" key found on most keyboards. An example of making the status of a control determinable is a visual status indicator on a keyboard.

Condition: Only for mobile applications: Where ICT has a key repeat function that cannot be turned off

Where ICT has a key repeat function that cannot be turned off:

a) the delay before the key repeat shall be adjustable to at least 2 seconds; and

b) the key repeat rate shall be adjustable down to one character per 2 seconds.5.8 Double-strike key acceptance

Condition: Only for mobile applications: Where ICT has a keyboard or keypad

Where ICT has a keyboard or keypad, the delay after any keystroke, during which an additional key-press will not be accepted if it is identical to the previous keystroke, shall be adjustable up to at least 0,5 seconds.

Condition: Only for mobile applications: Where ICT uses simultaneous user actions for its operation

Where ICT has a mode of operation requiring simultaneous user actions for its operation, such ICT shall provide at least one mode of operation that does not require simultaneous user actions to operate the ICT.

Note: Having to use both hands to open the lid of a laptop, having to press two or more keys at the same time or having to touch a surface with more than one finger are examples of simultaneous user actions

 

Condition: Where web pages or ICT provide two-way voice communication

Where ICT provides two-way voice communication, in order to provide good audio quality, that ICT shall be able to encode and decode two-way voice communication with a frequency range with an upper limit of at least 7 000 Hz.

Note: For the purposes of interoperability, support of Recommendation ITU-T G.722 is widely used.

Note: Where codec negotiation is implemented, other standardized codecs such as Recommendation ITU-T G.722.2 are sometimes used so as to avoid transcoding.

Condition: Where web pages or ICT provide a means for two-way voice communication

Where ICT is in a mode that provides a means for two-way voice communication, the ICT shall provide a means for two-way RTT communication, except where this would require design changes to add input or output hardware to the ICT.

Note: This requirement includes those products which do not have physical display or text entry capabilities but have the capability to connect to devices that do have such capabilities. It also includes intermediate ICT between the endpoints of the communication.

Note: There is no requirement to add: a hardware display, a hardware keyboard, or hardware to support the ability to connect to a display or keyboard, wired or wirelessly, if this hardware would not normally be provided.

Note: For the purposes of interoperability, support of Recommendation ITU-T T.140 is widely used.

Condition: Where web pages or ICT provide a means for two-way voice communication and for users to communicate by RTT

Where ICT provides a means for two-way voice communication and for users to communicate by RTT, it shall allow concurrent voice and text through a single user connection.

Note: With many-party communication, as in a conference system, it is allowed (but not required or necessarily recommended) that RTT be handled in a single display field and that "turn-taking" be necessary to avoid confusion (in the same way that turn-taking is required for those presenting/talking with voice).

Note: With many-party communication, best practice is for hand-raising for voice users and RTT users to be handled in the same way, so that voice and RTT users are in the same queue.

Note: With a many-party conference system that has chat as one of its features - the RTT (like the voice) would typically be separate from the chat so that RTT use does not interfere with chat (i.e. people can be messaging in the chat field while the person is presenting/talking with RTT - in the same manner that people message using the chat feature while people are talking with voice). RTT users would then use RTT for presenting and use the Chat feature to message while others are presenting (via Voice or RTT).

Note: The availability of voice and RTT running concurrently (and separately from chat) can also allow the RTT field to support text captioning when someone is speaking (and it is therefore not being used for RTT since it is not the RTT user's turn to speak).

Note: Where both server-side software and local hardware and software are required to provide voice communication, where neither part can support voice communication without the other and are sold as a unit for the voice communication function, the local and server-side components are considered a single product.

Condition: Where web pages or ICT have RTT send and receive capabilities

Where ICT has RTT send and receive capabilities, displayed sent text shall be visually differentiated from, and separated from, received text.

Note: The ability of the user to choose between having the send and receive text be displayed in-line or separately, and with options to select, allows users to display RTT in a form that works best for them. This would allow Braille users to use a single field and take turns and have text appear in the sequential way that they may need or prefer.

Condition: Where web pages or ICT have RTT send and receive capabilities

Where ICT has RTT send and receive capabilities, the send/receive direction of transmitted/received text shall be programmatically determinable, unless the RTT is implemented as closed functionality.

Note: This enables screen readers to distinguish between incoming text and outgoing text when used with RTT functionality.

Condition: Where web pages or ICT have RTT capabilities, and provide speaker identification for voice

Where ICT has RTT capabilities, and provides speaker identification for voice, the ICT shall provide speaker identification for RTT.

Note: This is necessary to enable both voice and RTT participants to know who is currently communicating, whether it be in RTT or voice.

Condition: Where web pages or ICT provide two-way voice communication, and have RTT capabilities

Where ICT provides two-way voice communication, and has RTT capabilities, the ICT shall provide a real-time visual indicator of audio activity on the display.

Note: The visual indicator may be a simple character position on the display that flickers on and off to reflect audio activity, or presentation of the information in another way that can be both visible to sighted users and passed on to deaf-blind users who are using a braille display.

Note: Without this indication a person who lacks the ability to hear does not know when someone is talking.

Condition: Where web pages or ICT with RTT functionality interoperate with other ICT with RTT functionality (as required by clause 6.2.1.1)

Where ICT with RTT functionality interoperates with other ICT with RTT functionality (as required by clause 6.2.1.1) they shall support the applicable RTT interoperability mechanisms described below:

a) ICT interoperating with other ICT directly connected to the Public Switched Telephone Network (PSTN), using Recommendation ITU-T V.18 or any of its annexes for text telephony signals at the PSTN interface

Note: In practice, new standards are introduced as an alternative codec/protocol that is supported alongside the existing common standard and used when all end-to-end components support it while technology development, combined with other reasons including societal development and cost efficiency, may make others become obsolete.

Note: Where multiple technologies are used to provide voice communication, multiple interoperability mechanisms may be needed to ensure that all users are able to use RTT.

Example: A conferencing system that supports voice communication through an internet connection might provide RTT over an internet connection using a proprietary RTT method (option c). However, regardless of whether the RTT method is proprietary or non-proprietary, if the conferencing system also offers telephony communication it will also need to support options a or b to ensure that RTT is supported over the telephony connection.

Condition: Where web pages or ICT with RTT functionality interoperate with other ICT with RTT functionality (as required by clause 6.2.1.1)

Where ICT with RTT functionality interoperates with other ICT with RTT functionality (as required by clause 6.2.1.1) they shall support the applicable RTT interoperability mechanisms described below:

b) ICT interoperating with other ICT using VOIP with Session Initiation Protocol (SIP) and using RTT that conforms to IETF RFC 4103. For ICT interoperating with other ICT using the IP Multimedia Sub-System (IMS) to implement VOIP, the set of protocols specified in ETSI TS 126 114, ETSI TS 122 173 and ETSI TS 134 229 describe how IETF RFC 4103 would apply

Note: In practice, new standards are introduced as an alternative codec/protocol that is supported alongside the existing common standard and used when all end-to-end components support it while technology development, combined with other reasons including societal development and cost efficiency, may make others become obsolete.

Note: Where multiple technologies are used to provide voice communication, multiple interoperability mechanisms may be needed to ensure that all users are able to use RTT.

Example: A conferencing system that supports voice communication through an internet connection might provide RTT over an internet connection using a proprietary RTT method (option c). However, regardless of whether the RTT method is proprietary or non-proprietary, if the conferencing system also offers telephony communication it will also need to support options a or b to ensure that RTT is supported over the telephony connection.

Condition: Where web pages or ICT with RTT functionality interoperate with other ICT with RTT functionality (as required by clause 6.2.1.1)

Where ICT with RTT functionality interoperates with other ICT with RTT functionality (as required by clause 6.2.1.1) they shall support the applicable RTT interoperability mechanisms described below:

c) ICT interoperating with other ICT using technologies other than a or b, above, using a relevant and applicable common specification for RTT exchange that is published and available for the environments in which they will be operating. This common specification shall include a method for indicating loss or corruption of characters

Note: In practice, new standards are introduced as an alternative codec/protocol that is supported alongside the existing common standard and used when all end-to-end components support it while technology development, combined with other reasons including societal development and cost efficiency, may make others become obsolete.

Note: Where multiple technologies are used to provide voice communication, multiple interoperability mechanisms may be needed to ensure that all users are able to use RTT.

Example: A conferencing system that supports voice communication through an internet connection might provide RTT over an internet connection using a proprietary RTT method (option c). However, regardless of whether the RTT method is proprietary or non-proprietary, if the conferencing system also offers telephony communication it will also need to support options a or b to ensure that RTT is supported over the telephony connection.

Condition: Where web pages or ICT with RTT functionality interoperate with other ICT with RTT functionality (as required by clause 6.2.1.1)

Where ICT with RTT functionality interoperates with other ICT with RTT functionality (as required by clause 6.2.1.1) they shall support the applicable RTT interoperability mechanisms described below:

d) ICT interoperating with other ICT using a standard for RTT that has been introduced for use in any of the above environments, and is supported by all of the other active ICT that support voice and RTT in that environment.

Note: In practice, new standards are introduced as an alternative codec/protocol that is supported alongside the existing common standard and used when all end-to-end components support it while technology development, combined with other reasons including societal development and cost efficiency, may make others become obsolete.

Note: Where multiple technologies are used to provide voice communication, multiple interoperability mechanisms may be needed to ensure that all users are able to use RTT.

Example: A conferencing system that supports voice communication through an internet connection might provide RTT over an internet connection using a proprietary RTT method (option c). However, regardless of whether the RTT method is proprietary or non-proprietary, if the conferencing system also offers telephony communication it will also need to support options a or b to ensure that RTT is supported over the telephony connection.

Condition: Where web pages or ICT utilise RTT input

Where ICT utilises RTT input, that RTT input shall be transmitted to the ICT network or platform on which the ICT runs within 500 ms of the time that the smallest reliably composed unit of text entry is available to the ICT for transmission. Delays due to platform or network performance shall not be included in the 500 ms limit.

Note: For character by character input, the "smallest reliably composed unit of text entry" would be a character. For word prediction it would be a word. For some voice recognition systems - the text may not exit the recognition software until an entire word (or phrase) has been spoken. In this case, the smallest reliably composed unit of text entry available to the ICT would be the word (or phrase).

Note: The 500 ms limit allows buffering of characters for this period before transmission so character by character transmission is not required unless the characters are generated more slowly than 1 per 500 ms.

Note: A delay of 300 ms, or less, produces a better impression of flow to the user.

Condition: Where web pages or ICT provide caller identification or similar telecommunications functions

Where ICT provides caller identification or similar telecommunications functions, the caller identification and similar telecommunications functions shall be available in text form as well as being programmatically determinable, unless the functionality is closed.

Condition: Where web pages or ICT provide real-time voice-based communication and also provide voice mail, auto-attendant, or interactive voice response facilities

Where ICT provides real-time voice-based communication and also provides voice mail, auto-attendant, or interactive voice response facilities, the ICT shall offer users a means to access the information and carry out the tasks provided by the ICT without the use of hearing or speech.

Note: Tasks that involve both operating the interface and perceiving the information would require that both the interface and information be accessible without use of speech or hearing.

Note: Solutions capable of handling audio, RTT and video media could satisfy the above requirement.

Condition: Where web pages or ICT that provide two-way voice communication includes real-time video functionality

Where ICT that provides two-way voice communication includes real-time video functionality, the ICT:

a) shall support at least QVGA resolution

Condition: Where ICT that provides two-way voice communication includes real-time video functionality, the ICT:

a) shall support a frame rate of at least 20 Frames Per Second (FPS)

Condition: Where ICT that provides two-way voice communication includes real-time video functionality, the ICT shall ensure a maximum time difference of 100 ms between the speech and video presented to the user.

Note: Recent research shows that, if audio leads the video, the intelligibility suffers much more than the reverse.

Condition: Where web pages or ICT that provide two-way voice communication includes real-time video functionality

Where ICT provides two-way voice communication, and includes real-time video functionality, the ICT shall provide a real-time visual indicator of audio activity.

Note: The visual indicator may be a simple visual dot or LED, or other type of on/off indicator, that flickers to reflect audio activity.

Note: Without this indication a person who lacks the ability to hear does not know when someone is talking.

Condition: Where web pages or ICT provide speaker identification for voice users

Where ICT provides speaker identification for voice users, it shall provide a means for speaker identification for realtime signing and sign language users once the start of signing has been indicated.

Note: The speaker ID can be in the same location as for voice users for multiparty calls.

Note: This mechanism might be triggered manually by a user, or automatically where this is technically achievable.

 

Condition: Where web content or ICT displays video with synchronized audio

Where ICT displays video with synchronized audio, it shall have a mode of operation to display the available captions. Where closed captions are provided as part of the content, the ICT shall allow the user to choose to display the captions.

Note: Captions may contain information about timing, colour and positioning. This caption data is necessary for caption users. Timing is used for caption synchronization. Colour can be used for speaker identification. Position can be used to avoid obscuring important information.

Note: If a Braille device is connected, the ICT should provide an option to display captions on the Braille device.

Note: Clause 7.1.1 refers to the ability of the player to display captions. Clauses 9.1.2.2, 10.1.2.2 and 11.1.2.2 refer to the provision of captions for the content (the video).

Condition: Where web content or ICT displays captions

Where ICT displays captions, the mechanism to display captions shall preserve synchronization between the audio and the corresponding captions as follows:

Captions in recorded material: within 100 ms of the time stamp of the caption.

Live captions: within 100 ms of the availability of the caption to the player.

Condition: Where web pages or ICT transmit, convert or record video with synchronized audio

Where ICT transmits, converts or records video with synchronized audio, it shall preserve caption data such that it can be displayed in a manner consistent with clauses 7.1.1 and 7.1.2. Additional presentational aspects of the text such as screen position, text colours, text style and text fonts may convey meaning, based on regional conventions. Altering these presentational aspects could change the meaning and should be avoided wherever possible.

Condition: Where web content or ICT displays captions

Where ICT displays captions, it shall provide a way for the user to adapt the displayed characteristics of captions to their individual requirements, except where the captions are displayed as unmodifiable characters.

Note: Defining the background and foreground colour of subtitles, font type, size opacity of the background box of subtitles, and the contour or border of the fonts can contribute to meeting this requirement.

Note: Subtitles that are bitmap images are examples of unmodifiable characters.

Condition: Where web content or ICT displays video with synchronized audio

Where ICT displays video with synchronized audio, it shall have a mode of operation to provide a spoken output of the available captions, except where the content of the displayed captions is not programmatically determinable.

Note: Being able to manage speech output range for spoken subtitles independently from general ICT speech is preferable for most users. That is possible when the audio file with spoken subtitle is delivered in a separate audio track and mixed in the end users device.

Note: Presenting the separate audio track with spoken subtitles in synchronization with the displayed subtitles/captions improves understandability of the subtitles.

Note: Providing subtitles/captions as separate text-streams, facilitates converting the respective texts into audio.

Note: Subtitles that are bitmap images are examples where the content of the displayed captions will not be programmatically determinable.

Condition: Where web content or ICT displays video with synchronized audio

Where ICT displays video with synchronized audio, it shall provide a mechanism to select and play available audio description to the default audio channel. Where video technologies do not have explicit and separate mechanisms for audio description, an ICT is deemed to satisfy this requirement if the ICT enables the user to select and play several audio tracks.

Condition: Where web content or ICT has a mechanism to play audio description

Where ICT has a mechanism to play audio description, it shall preserve the synchronization between the audio/visual content and the corresponding audio description.

Condition: Where web pages or ICT transmit, convert, or record video with synchronized audio

Where ICT transmits, converts, or records video with synchronized audio, it shall preserve audio description data such that it can be played in a manner consistent with clauses 7.2.1 and 7.2.2.

Condition: Where web pages or ICT primarily display materials containing video with associated audio content

Where ICT primarily displays materials containing video with associated audio content, user controls to activate subtitling and audio description shall be provided to the user at the same level of interaction (i.e. the number of steps to complete the task) as the primary media controls.

Note: Primary media controls are the set of controls that the user most commonly uses to control media.

Note: Products that have a general hardware volume control, such as a telephone, or a laptop which can be configured to display video through software but which is not its primary purpose, would not need dedicated hardware controls for captions and descriptions; however software controls, or hardware controls mapped through software, would need to be at the same level of interaction.

Note: It is best practice for ICT to include additional controls enabling the user to select whether captions and audio description are turned on or off by default.

 

Condition: Only for websites: Where ICT is a web page

Where ICT is a web page, it shall satisfy all the following five WCAG 2.1 conformance requirements at Level AA:

Conformance level

Full pages

Complete processes

Only Accessibility-Supported Ways of Using Technologies

Non-interference

Note: A Web page that meets all of requirements 9.1 to 9.4, or where a Level AA conforming alternate version (as defined in WCAG 2.1) is provided, will meet conformance requirement 1.

Note: According to W3C: "WCAG 2.1 extends Web Content Accessibility Guidelines 2.0, which was published as a W3C Recommendation December 2008. Content that conforms to WCAG 2.1 also conforms to WCAG 2.0, and therefore to policies that reference WCAG 2.0."

Note: Conformance requirement 5 states that all content on the page, including content that is not otherwise relied upon to meet conformance, meets clauses 9.1.4.2, 9.2.1.2, 9.2.2.2 and 9.2.3.1

 

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading, it shall meet requirement 5.1.3.6 (Speech output for non-text content).

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading and where pre-recorded auditory information is needed to enable the use of closed functions of ICT, the functionality of software that provides a user interface shall meet requirement 5.1.5 (Visual output for auditory information).

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading, it shall meet requirement 5.1.3.7 (Speech output for video information).

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading, it shall meet requirement 5.1.3.7 (Speech output for video information).

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface and is closed to assistive technologies, in at least one mode of operation the ICT shall present to the user, in an audio form, the purpose of each input field collecting information about the user when the input field serves a purpose identified in the WCAG 2.1 Input Purposes for User Interface Components section.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is not able to access the enlargement features of platform or assistive technology, it shall meet requirement 5.1.4 (Functionality closed to text enlargement).

Note: Because the text rendering support in a closed environment may be more limited than the support found in user agents for the Web, meeting the present clause in a closed environment may place a much heavier burden on the content author.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading, it shall meet requirement 5.1.3.6 (Speech output for non-text content).

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is closed to keyboards or keyboard interface, it shall meet requirement 5.1.6.1 (Operation without keyboard interface: Closed functionality).

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is closed to keyboards or keyboard interface, it shall meet requirement 5.1.6.1 (Operation without keyboard interface: Closed functionality).

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading, it shall meet requirement 5.1.3.14 (Spoken languages).

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading

Where ICT is non-web software that provides a user interface which is closed to assistive technologies for screen reading, it shall meet requirement 5.1.3.15 (Non-visual error identification).

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where the software provides a user interface it shall use the applicable documented platform accessibility services. If the documented platform accessibility services do not allow the software to meet the applicable requirements of clauses 11.5.2.5 to 11.5.2.17, then software that provides a user interface shall use other documented services to interoperate with assistive technology.

Note: The term "documented platform accessibility services" refers to the set of services provided by the platform according to clauses 11.5.2.1 and 11.5.2.2.

Note: It is best practice to develop software using toolkits that automatically implement the underlying platform accessibility services.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where the software provides a user interface it shall, by using the services as described in clause 11.5.2.3, make the user interface elements' role, state(s), boundary, name, and description programmatically determinable by assistive technologies.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where the software provides a user interface it shall, by using the services as described in clause 11.5.2.3, make the row and column of each cell in a data table, including headers of the row and column if present, programmatically determinable by assistive technologies.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where the software provides a user interface, it shall, by using the services as described in clause 11.5.2.3, make the current value of a user interface element and any minimum or maximum values of the range, if the user interface element conveys information about a range of values, programmatically determinable by assistive technologies.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where the software provides a user interface it shall expose the relationship that a user interface element has as a label for another element, or of being labelled by another element, using the services as described in clause 11.5.2.3, so that this information is programmatically determinable by assistive technologies.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where the software provides a user interface it shall, by using the services as described in clause 11.5.2.3, make the relationship between a user interface element and any parent or children elements programmatically determinable by assistive technologies.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where the software provides a user interface it shall, by using the services as described in clause 11.5.2.3, make the text contents, text attributes, and the boundary of text rendered to the screen programmatically determinable by assistive technologies

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where the software provides a user interface it shall, by using the services as described in clause 11.5.2.3, make a list of available actions that can be executed on a user interface element, programmatically determinable by assistive technologies.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where permitted by security requirements, software that provides a user interface shall, by using the services as described in clause 11.5.2.3, allow the programmatic execution of the actions exposed according to clause 11.5.2.11 by assistive technologies.

Note: In some cases the security requirements imposed on a software product may forbid external software from interfering with the ICT product. Examples of systems under strict security requirements are systems dealing with intelligence activities, cryptologic activities related to national security, command and control of military forces.

Note: Assistive technologies may be required to maintain the same level of security as the standard input mechanisms supported by the platform.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where software provides a user interface it shall, by using the services as described in clause 11.5.2.3, make information and mechanisms necessary to track focus, text insertion point, and selection attributes of user interface elements programmatically determinable by assistive technologies.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where permitted by security requirements, software that provides a user interface shall, by using the services as described in clause 11.5.2.3, allow assistive technologies to programmatically modify focus, text insertion point, and selection attributes of user interface elements where the user can modify these items.

Note: In some cases the security requirements imposed on a software product may forbid external software from interfering with the ICT product and so this requirement would not apply. Examples of systems under strict security requirements are systems dealing with intelligence activities, cryptologic activities related to national security, command and control of military forces.

Note: Assistive technologies may be required to maintain the same level of security as the standard input mechanisms supported by the platform.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where software provides a user interface it shall, by using the services as described in clause 11.5.2.3, notify assistive technologies about changes in those programmatically determinable attributes of user interface elements that are referenced in requirements 11.5.2.5 to 11.5.2.11 and 11.5.2.13.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where permitted by security requirements, software that provides a user interface shall, by using the services as described in clause 11.5.2.3, allow assistive technologies to programmatically modify states and properties of user interface elements, where the user can modify these items.

Note: In some cases the security requirements imposed on a software product may forbid external software from interfering with the ICT product and so this requirement would not apply. Examples of systems under strict security requirements are systems dealing with intelligence activities, cryptologic activities related to national security, command and control of military forces.

Note: Assistive technologies may be required to maintain the same level of security as the standard input mechanisms supported by the platform.

Condition: Only for mobile applications: Where ICT is non-web software that provides a user interface

Where permitted by security requirements, software that provides a user interface shall, by using the services as described in clause 11.5.2.3, allow assistive technologies to modify values and text of user interface elements using the input methods of the platform, where a user can modify these items without the use of assistive technology.

Note: In some cases the security requirements imposed on a software product may forbid external software from interfering with the ICT product and so this requirement would not apply. Examples of systems under strict security requirements are systems dealing with intelligence activities, cryptologic activities related to national security, command and control of military forces.

Note: Assistive technologies may be required to maintain the same level of security as the standard input mechanisms supported by the platform.

Condition: Where ICT is non-web software that provides a user interface

Where software provides a user interface it shall not disrupt those documented accessibility features that are defined in platform documentation except when requested to do so by the user during the operation of the software.

Condition: For web pages: unconditional. For mobile applications: Where ICT is non-web software that is not designed to be isolated from its platform, and that provides a user interface

Where software is not designed to be isolated from its platform, and provides a user interface, that user interface shall follow the values of the user preferences for platform settings for: units of measurement, colour, contrast, font type, font size, and focus cursor except where they are overridden by the user.

Note: Software that is isolated from its underlying platform has no access to user settings in the platform and thus cannot adhere to them.

Note: For web content, the underlying platform is the user agent.

Note: This does not preclude the software from having additional values for a setting as long as there is one mode where the application will follow the system settings even if more restricted.

Condition: Where web content or ICT is an authoring tool

Authoring tools shall conform to clauses 11.8.2 to 11.8.5 to the extent that information required for accessibility is supported by the format used for the output of the authoring tool.

Condition: Where web content or ICT is an authoring tool

Authoring tools shall enable and guide the production of content that conforms to clauses 9 (Web content) or 10 (Non-Web content) as applicable.

Note: Authoring tools may rely on additional tools where conformance with specific requirements is not achievable by a single tool. For example, a video editing tool may enable the creation of video files for distribution via broadcast television and the web, but authoring of caption files for multiple formats may be provided by a different tool.

Condition: Where web content or ICT is an authoring tool

Note: Restructuring transformations are transformations in which the content technology stays the same, but the structural features of the content are changed (e.g. linearizing tables, splitting a document into pages).

Note: Re-coding transformations are transformations in which the technology used to encode the content is changed.

Condition: Where web content or ICT is an authoring tool

If the accessibility checking functionality of an authoring tool can detect that content does not meet a requirement of clauses 9 (Web) or 10 (Non-web documents) as applicable, then the authoring tool shall provide repair suggestion(s).

Note: This does not preclude automated and semi-automated repair which is possible (and encouraged) for many types of content accessibility problems.

Condition: Where web content or ICT is an authoring tool

When an authoring tool provides templates, at least one template that supports the creation of content that conforms to the requirements of clauses 9 (Web) or 10 (Non-web documents) as applicable shall be available and identified as such.

 

Condition: For web pages and mobile applications (unconditional)

Product documentation provided with the ICT whether provided separately or integrated within the ICT shall list and explain how to use the accessibility and compatibility features of the ICT.

Note: Accessibility and compatibility features include accessibility features that are built-in and accessibility features that provide compatibility with assistive technology.

Note: It is best practice to use WebSchemas/Accessibility 2.0 to provide meta data on the accessibility of the ICT.

Note: The accessibility statement and help pages are both examples of the provision of product information.

Condition: For web pages and mobile applications (unconditional)

Product documentation provided with the ICT shall be made available in at least one of the following electronic formats:

a) a Web format that conforms to the requirements of clause 9

b) a non-web format that conforms to the requirements of clause 10

Note: This does not preclude the possibility of also providing the product documentation in other formats (electronic, printed or audio) that are not accessible.

Note: It also does not preclude the possibility of providing alternate formats that meet the needs of some specific type of users (e.g. Braille documents for blind people or easy-to-read information for persons with limited cognitive, language and learning abilities).

Note: Where documentation is incorporated into the ICT, the documentation falls under the requirements for accessibility in the present document.

Note: A user agent that supports automatic media conversion would be beneficial to enhancing accessibility.

Condition: For web pages and mobile applications (unconditional)

ICT support services shall provide information on the accessibility and compatibility features that are mentioned in the product documentation.

Note: Accessibility and compatibility features include accessibility features that are built-in and accessibility features that provide compatibility with assistive technology.

Condition: For web pages and mobile applications (unconditional)

ICT support services shall accommodate the communication needs of individuals with disabilities either directly or through a referral point.

Condition: For web pages and mobile applications (unconditional)

Documentation provided by support services shall be made available in at least one of the following electronic formats:

a) a Web format that conforms to clause 9; or

b) a non-web format that conforms to clause 10.

Note: This does not preclude the possibility of also providing the documentation in other formats (electronic or printed) that are not accessible.

Note: It also does not preclude the possibility of providing alternate formats that meet the needs of some specific type of users (e.g. Braille documents for blind people or easy-to-read information for persons with limited cognitive, language and learning abilities).

Note: Where the support documentation is incorporated into the ICT, the documentation falls under the requirements for accessibility in the present document.

Note: A user agent that supports automatic media conversion would be beneficial to enhancing accessibility.

 

Eine Übersicht der neuesten Änderungen in der Norm finden Sie auch auf der Website der Europäischen Kommission.

Die zusätzlichen Kriterien finden Sie auch in den Tabellen A.1 bzw. A.2 des Annex A der Norm EN 301 549 V3.2.1.

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