- abbreviation
-
shortened form of a word, phrase, or name where the abbreviation has not become part of the language
Opmerking 1:
This includes initialisms and acronyms where:
-
initialisms are shortened forms of a name or phrase made from the initial letters of words or syllables contained in that name or phrase
Opmerking 1:
Not defined in all languages.
Voorbeeld 1:
SNCF is a French initialism that contains the initial letters of the
Société Nationale des Chemins de Fer, the French national railroad.
Voorbeeld 2:
ESP is een acroniem voor extrasensoriële perceptie.
-
acronyms
are abbreviated forms made from the initial letters or parts of other words (in a name or phrase) which may be pronounced as a word
Voorbeeld: NOAA is an acronym made from the initial letters of the National Oceanic and Atmospheric Administration in the United States.
Opmerking 2:
Some companies have adopted what used to be an initialism as their company name. In these cases, the new name of the company is the letters (bijvoorbeeld, Ecma) and the word is no longer considered an abbreviation.
- door toegankelijkheid ondersteund
-
supported by users'
hulptechnologieën as well as the accessibility features in browsers and other
user agents
To qualify as an accessibility-supported use of a Webcontent technologie (or feature of a technologie), both 1 and 2 must be satisfied for a Webcontent technologie (or feature):
-
The way that the
Webcontent technologie is used must be supported by users' hulptechnologie (AT). This means that the way that the technologie is used has been tested for interoperability with users' hulptechnologie in the
human language(s) of the content,
AND
-
The Webcontent technologie must have accessibility-supported user agents that are available to users. This means that at least one of the following four statements is true:
-
The technologie is supported natively in widely-distributed user agents that are also
door toegankelijkheid ondersteund (such as HTML and CSS);
OR
-
The technologie is supported in a widely-distributed plug-in that is also
door toegankelijkheid ondersteund;
OR
-
The content is available in a closed environment, such as a university or corporate network, where the user agent required by the technologie and used by the organization is also
door toegankelijkheid ondersteund;
OR
-
The user agent(s) that support the technologie are
door toegankelijkheid ondersteund and are available for download or purchase in a way that:
Opmerking 1:
The WCAG Working group and the W3C do not specify which or how much support by hulptechnologieën there must be for a particular use of a Web technologie in order for it to be classified as
door toegankelijkheid ondersteund. (See
Niveau of Assistive Technology Support Needed for "Accessibility Support".)
Opmerking 2:
Web technologieën can be used in ways that are not
door toegankelijkheid ondersteund as long as they are not
relied upon and the page as a whole meets the Conformiteitseisen, including
Conformiteitseis 4: Only Accessibility-Supported Ways of Using Technologies and
Conformiteitseis 5: Niet-interferentie, are met.
Opmerking 3:
When a
Web Technology is used in a way that is "door toegankelijkheid ondersteund," it does not imply that the entire technologie or all uses of the technologie are supported. Most technologieën, including HTML, lack support for at least one feature or use. Pages conform to WCAG only if the uses of the technologie that are
door toegankelijkheid ondersteund can be relied upon to meet WCAG eisen.
Opmerking 4:
When citing Webcontent technologieën that have multiple versions, the version(s) supported should be specified.
Opmerking 5:
One way for authors to locate uses of a technologie that are
door toegankelijkheid ondersteund would be to consult compilations of uses that are documented to be
door toegankelijkheid ondersteund. (See
Begrijpen Accessibility-Supported Web Technology Uses.) Authors, companies, technologie vendors, or others may document accessibility-supported ways of using Webcontent technologieën. However, all ways of using technologieën in the documentation would need to meet the definitie of accessibility-supported Webcontent technologieën above.
- alternatief voor gesynchroniseerde media
-
document including correctly sequenced text beschrijvings of
gesynchroniseerde visual and auditory Informatie and providing a means for achieving the outcomes of any
gesynchroniseerde interaction
Opmerking: A screenplay used to creëer the gesynchroniseerde media content would meet this definitie only if it was corrected to accurately represent the final gesynchroniseerde media after editing.
- ambiguous to users in general
-
the purpose cannot be determined from the link and all Informatie of the Webpagina 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)
Voorbeeld: The word guava in the following sentence "One of the notable exports is guava" is a link. The link could lead to a definitie of guava, a chart listing the quantity of guava exported or a photograph of people harvesting guava. Until the link is activated, all readers are unsure and the person with a disability is
not at any disadvantage.
- ASCII art
-
picture created by a spatial arrangement of characters or glyphs (typically from the 95 printable characters defined by ASCII).
- hulptechnologie (as used in this document)
-
hardware and/or software that acts as a
user agent, or along with a mainstream user agent, to lever functionaliteit to meet the eisen of users with disabilities that go beyond those offered by mainstream user agents
Opmerking 1:
functionaliteit provided by hulptechnologie includes alternatief presentaties (e.g., as synthesized speech or magnified content), alternatief input methods (e.g., voice), additionele navigation or orientation mechanisms, and content transformations (e.g., to make tables more toegankelijkheid).
Opmerking 2:
Assistive technologieën often communicate data and messages with mainstream user agents by using and monitoring
APIs.
Opmerking 3:
The distinction between mainstream user agents and hulptechnologieën is not absolute. Many mainstream user agents lever some features to assist individuen with disabilities. The basic difference is that mainstream user agents target broad and diverse audiences that usually include people with and without disabilities. Assistive technologieën target narrowly defined populations of users with specific disabilities. The assistance provided by an hulptechnologie is more specific and appropriate to the needs of its target users. The mainstream user agent may lever important functionaliteit to hulptechnologieën like retrieving Webcontent from program objects or parsing markup into identifiable bundles.
Voorbeeld: Assistive technologieën that are important in the context of this document include the following:
-
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, kleur, 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 Informatie through synthesized speech or braille;
-
text-to-speech software, which is used by some people with cognitive, language, and leermoeilijkheden 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 sim
ulate 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.
- audio
-
the technologie of sound reproduction
Opmerking: Audio can be created synthetically (including speech synthesis), recorded from real world sounds, or both.
- audio beschrijving
-
narration added to the soundtrack to beschrijven important visual details that cannot be understood from the main soundtrack alone
Opmerking 1:
Audio beschrijving of
video provides Informatie about actions, characters, scene changes, on-screen text, and other visual content.
Opmerking 2:
In standard audio beschrijving, narration is added during existing pauses in dialogue. (See also
uitgebreid audio beschrijving.)
Opmerking 3:
Where all of the
video Informatie is already provided in existing
audio, no additionele audio beschrijving is necessary.
Opmerking 4:
Also called "video beschrijving" and "descriptive narration."
- audio-only
-
a
gesynchroniseerde presentatie that contains only
audio (no
video and no interaction)
-
knipperen
-
switch back and forth between two visual states in a way that is meant to draw attention
Opmerking: See also
flits. It is possible for something to be large enough and blink brightly enough at the right frequency to be also classified as a flash.
- blocks of text
-
more than one sentence of text
- CAPTCHA
-
initialism for "Completely Automated Public Turing test to tell Computers and Humans Apart"
Opmerking 1:
CAPTCHA tests often involve asking the user to type in text that is displayed in an obscured image or audio file.
Opmerking 2:
A Turing test is any system of tests designed to differentiate a human from a computer. It is named after famed computer scientist Alan Turing. The term was coined by researchers at Carnegie Mellon University.
[CAPTCHA]
- captions
-
gesynchroniseerde visual and/or
tekstalternatief for both speech and non-speech audio Informatie needed to understand the media content
Opmerking 1:
Bijschriften are similar to dialogue-only subtitles except captions convey not only the content of spoken dialogue, but also equivalents for non-dialogue audio Informatie needed to understand the program content, including sound effects, music, laughter, speaker identification and location.
Opmerking 2:
Closed Bijschriften are equivalents that can be turned on and off with some players.
Opmerking 3:
Open Bijschriften are any captions that cannot be turned off. Bijvoorbeeld, if the captions are visual equivalent
beelden van tekst embedded in
video.
Opmerking 4:
Bijschriften should not obscure or obstruct relevant Informatie in the video.
Opmerking 5:
In some countries, captions are called subtitles.
Opmerking 6:
Audio beschrijvings can be, but do not need to be, captioned since they are beschrijvings of Informatie that is already presented visually.
- changes of context
-
major changes in the content of the
Webpagina that, if made without user awareness, can disorient users who are not able to view the entire page simultaneously
Changes in context include changes of:
-
user agent;
-
viewport;
-
focus;
-
content that changes the meaning of the
Webpagina.
Opmerking: A change of content is not always a change of context.
Changes in content, such as an expanding outline, dynamic menu,
or a tab control do not necessarily change the context,
unless they also change one of the above (e.g., focus).
Voorbeeld: Opening a new window, moving focus to a different
component, going to a new page (including anything that would look to a user as if they had moved to a new page) or significantly re-arranging the content of a page are examples of changes of context.
-
conformiteit
-
satisfying all the eisen of a given standard,
Richtlijn or specification
-
conforming alternate version
-
version that
-
conforms at the designated level, and
-
provides all of the same information and
functionaliteit in the same
human language, and
-
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, or
-
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
Opmerking 1:
In this definition, "can only be reached" means that there is some mechanism, such as a conditional redirect, that prevents a user from "reaching" (loading) the non-conforming page unless the user had just come from the conforming
version.
Opmerking 2:
The alternate version does not need to be matched page for page with the original (e.g., the conforming alternate version may consist of multiple pages).
Opmerking 3:
If multiple language versions are available, then conforming alternate versions are required for each language offered.
Opmerking 4:
Alternate versions may be provided to accommodate different technologie environments or user groups. Each version should be as conformant as possible. One version would need to be fully conformant in order to meet
Conformiteitseis 1.
Opmerking 5:
The conforming alternatief version does not need to reside within the scope of conformiteit, or even on the same Web site, as long as it is as freely available as the non-conforming version.
Opmerking 6:
Alternate versions should not be confused with
supplementary content, which support the original page and enhance comprehension.
Opmerking 7:
Setting user preferences within the content to produce a conforming version is an acceptable mechanism for reaching another version as long as the method used to set the preferences is
door toegankelijkheid ondersteund.
See
Begrijpen Conforming Alternate Versions
- content (Webcontent)
-
information and sensorieel experience to be communicated to the user by means of a
user agent, including
code or markup that definieert the content's
structure,
presentation, and interactions
- context-sensitive help
-
help text that provides information related to the function currently being performed
Opmerking: Clear labels can act as context-sensitive help.
- contrastverhouding
-
(L1 + 0.05) / (L2 + 0.05), where
Opmerking 1:
Contrastverhoudingen can range from 1 to 21 (commonly written 1:1 to 21:1).
Opmerking 2:
Because authors do not have control over user settings as to how text is rendered (bijvoorbeeld font smoothing or anti-aliasing), the contrastverhouding for text can be evaluated with anti-aliasing turned off.
Opmerking 3:
For the purpose of Success Criteria 1.4.3 and 1.4.6, contrast is measured with respect to the specified background over which the text is rendered in normal usage. If no background kleur is specified, then white is assumed.
Opmerking 4:
Background kleur is the specified kleur of content over which the text is to be rendered in normal usage. It is a failure if no background kleur is specified when the text kleur is specified, because the user's default background kleur is unknown and cannot be evaluated for voldoende contrast. For the same reason, it is a failure if no text kleur is specified when a background kleur is specified.
Opmerking 5:
When there is a border around the letter, the border can add contrast and would be used in calculating the contrast between the letter and its background. A narrow border around the letter would be used as the letter. A wide border around the letter that fills in the inner details of the letters acts as a halo and would be considered background.
Opmerking 6:
WCAG conformiteit should be evaluated for kleur pairs specified in the content that an author would expect to
appear adjacent in typical presentatie. Authors need not consider unusual presentaties, such as kleur changes made
by the user agent, except where caused by authors' code.
-
correct reading sequence
-
any sequence where words and paragraphs are
presented in an order that does not change the meaning of the content
- noodsituatie
-
a sudden, unexpected situation or occurrence that requires immediate action to preserve health, safety,
or property
- essentieel
-
if removed, would fundamentally change the information or functionaliteit of the content,
and information and functionaliteit cannot be achieved in another way that would conform
- uitgebreid audio beschrijving
-
audio beschrijving that is added to an audiovisual presentatie by pausing the
video so that there is time
to add additional beschrijving
Opmerking: This technique is only used when the sense of the
video
would be lost without the additional
audio beschrijving
and the pauses between dialogue/narration are too short.
-
flits
-
a pair of opposing changes in
relative luminance
that can cause seizures in some people if it is large enough and in the right frequency range
- functionaliteit
-
processes and outcomes achievable through user action
- general flits and red flits thresholds
-
a
flits or rapidly changing image sequence is below the threshold (i.e., content passes) if any of the following are true:
-
there are no more than three
general flashes and / or no more than three red flashes
within any one-second period; or
-
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 is defined as a pair of opposing changes in
relative luminance of 10% or more of the maximum relative luminance where the relative luminance of the darker image is below 0.80; and where "a pair of opposing changes" is an increase followed by a decrease, or a decrease followed by an increase, and
-
A red flash is defined as any pair of opposing transitions involving a saturated red.
Exception: Flashing that is a fine, balanced, pattern such as white noise or an alternating checkerboard pattern with "squares" smaller than 0.1 degree (of visual field at typical viewing distance) on a side does not violate the thresholds.
Opmerking 1:
For general software or Webcontent, using a 341 x 256 pixel rectangle anywhere on the displayed screen area when the content is viewed at 1024 x 768 pixels will lever a good estimate of a 10 degree visual field for standard screen sizes and viewing distances (e.g., 15-17 inch screen at 22-26 inches). (Higher resolutions displays showing the same rendering of the content yield smaller and safer images so it is lower resolutions that are used to define the thresholds.)
Opmerking 2:
A transition is the change in relative luminance (or relative luminance/color for red flashing) between adjacent peaks and valleys in a plot of relative luminance (or relative luminance/color for red flashing) measurement against time. A flits consists of two opposing transitions.
Opmerking 3:
The current working definition in the field for
"pair of opposing transitions involving a saturated red"
is where, for either or both states involved in each transition, R/(R+ G + B) >= 0.8,
and the change in the value of (R-G-B)x320 is > 20 (negative values of (R-G-B)x320 are set to zero)
for both transitions. R, G, B values range from 0-1 as specified in "relative luminance" definition.
[HARDING-BINNIE]
Opmerking 4:
Tools are available that will carry out analysis from video screen capture. However, no tool is necessary to evaluate for this condition if flashing is less than or equal to 3 flashes in any one second. Content automatically passes (see #1 and #2 above).
- human language
-
language that is spoken, written or signed (through visual or tactile means) to communicate with humans
- idiom
-
phrase whose meaning cannot be deduced from the meaning of the individual words and the specific words cannot be changed without losing the meaning
Opmerking: idioms cannot be translated directly, word for word, without losing their (cultural or language-dependent) meaning.
Voorbeeld 1:
In English, "spilling the beans" means "revealing a secret." However, "knocking over the beans" or "spilling the vegetables" does not mean the same thing.
Voorbeeld 2:
In Japanese, the phrase "??????" literally translates into "he throws a spoon," but it means that there is nothing he can do and finally he gives up.
Voorbeeld 3:
In Dutch, "Hij ging met de kippen op stok" literally translates into "He went to roost with the chickens," but it means that he went to bed early.
- image of text
-
text that has been rendered in a non-text form (e.g., an image) in order to achieve a particular visual effect
Opmerking: This does not include
tekst that is part of a picture that contains significant other visual content.
Voorbeeld: A person's name on a nametag in a photograph.
- informative
-
for information purposes and not required for conformiteit
- input error
-
information provided by the user that is not accepted
Opmerking: This includes:
-
Information that is required by the
Webpagina but omitted by the user
-
Information that is provided by the user but that falls outside the required data format or values
- jargon
-
words used in a particular way by people in a particular field
Voorbeeld: The word StickyKeys is jargon from the field of assistive
technologie/accessibility.
- keyboard interface
-
interface used by software to obtain keystroke input
Opmerking 1:
A keyboard interface allows users to lever keystroke input to programs even if the native technologie does not contain a keyboard.
Voorbeeld: A touchscreen PDA has a keyboard interface built into its operating system as well as a connector for external keyboards. Applications on the PDA can use the interface to obtain keyboard input either from an external keyboard or from other applications that lever simulated keyboard output, such as handwriting interpreters or speech-to-text applications with "keyboard emulation" functionaliteit.
Opmerking 2:
Operation of the application (or parts of the application) through a keyboard-operated mouse emulator, such as MouseKeys, does not qualify as operation through a keyboard interface because operation of the program is through its pointing device interface, not through its keyboard interface.
- label
-
tekst
or other component with a
tekstalternatief
that is presented to a user to identify a component within Web
content
Opmerking 1:
A label is presented to all users whereas the
name may be hidden and only exposed by hulptechnologie. In many (but not all) cases the name and the label are the same.
Opmerking 2:
The term label is not limited to the label element in HTML.
- large scale (text)
-
with at least 18 point or 14 point bold or font size that would yield equivalent size for Chinese, Japanese and Korean (CJK) fonts
Opmerking 1:
Fonts with extraordinarily thin strokes or unusual features and Karakteristieken that reduce the familiarity of their letter forms are harder to read, especially at lower contrast levels.
Opmerking 2:
Font size is the size when the content is delivered. It does not include resizing that may be done by a user.
Opmerking 3:
The actual size of the character that a user sees is dependent both on the author-defined size and the user's display or user-agent settings. For many mainstream body text fonts, 14 and 18 point is roughly equivalent to 1.2 and 1.5 em or to 120% or 150% of the default size for body text (assuming that the body font is 100%), but authors would need to check this for the particular fonts in use. When fonts are defined in relative units, the actual point size is calculated by the user agent for display. The point size should be obtained from the user agent, or calculated based on font metrics as the user agent does, when evaluating this succescriterium. Users who have low vision would be responsible for choosing appropriate settings.
Opmerking 4:
When using text without specifying the font size, the smallest font size used on major browsers for unspecified text would be a reasonable size to assume for the font. If a niveau 1 heading is rendered in 14pt bold or higher on major browsers, then it would be reasonable to assume it is large text. Relative scaling can be calculated from the default sizes in a similar fashion.
Opmerking 5:
The 18 and 14 point sizes for roman texts are taken from the minimum size for grote letters (14pt) and the larger standard font size (18pt). For other fonts such as CJK languages, the "equivalent" sizes would be the minimum grote letters size used for those languages and the next larger standard grote letters size.
- legal commitments
-
transactions where the person incurs a legally binding obligation or benefit
Voorbeeld: A marriage license, a stock trade (financial and legal), a will, a loan, adoption, signing up for the army, a contract of any type, etc.
- link purpose
-
nature of the result obtained by activating a hyperlink
-
direct
-
information captured from a
real-world event and transmitted to the receiver with no more than a broadcast delay
Opmerking 1:
A broadcast delay is a short (usually automated) delay, bijvoorbeeld used in order to give the broadcaster time to queue or censor the audio (or video) feed, but not voldoende to allow significant editing.
Opmerking 2:
If information is completely computer generated, it is not live.
- lower secondary education level
-
the two or three year period of education that begins after completion of six years of school and ends nine years after the beginning of
primary education
Opmerking: This definition is based on the International Standard Classification of Education
[UNESCO].
- mechanism
-
process or technique for achieving a result
Opmerking 1:
The mechanism may be explicitly provided in the content, or may be
relied upon to be provided by either the platform or by
user agents, including
hulptechnologieën.
Opmerking 2:
The mechanism needs to meet all succescriteria for the conformiteit niveau claimed.
- media alternatief for text
-
media that presents no more information than is already presented in text (directly or via text alternatieven)
Opmerking: A media alternatief for text is provided for those who benefit from alternate representations of text. Media alternatieven for text may be audio-only, video-only (including sign-language video), or audio-video.
- name
-
text by which software can identify a component within Webcontent to the user
Opmerking 1:
The name may be hidden and only exposed by hulptechnologie, whereas a
label is presented to all users.
In many (but not all) cases, the label and the name are the same.
Opmerking 2:
This is unrelated to the name attribute in HTML.
- navigated sequentially
-
navigated in the order defined for advancing focus (from one element to the next) using a
keyboard interface
- non-text content
-
any content that is not a sequence of characters that can be
programmatisch bepaald or where the sequence is not expressing something in
human language
Opmerking: This includes
ASCII Art (which is a pattern of characters), emoticons,
leetspeak (which uses character substitution), and images representing text
- normative
-
required for conformiteit
Opmerking 1:
One may conform in a variety of well-defined ways to this document.
Opmerking 2:
Content identified as "informative" or "non-normative" is never required for conformiteit.
- op een venster even groot als het volle scherm
-
on the most common sized desktop/laptop display with the viewport Maximaliseerd
Opmerking: Since people generally keep their computers for several years,
it is best not to rely on the latest desktop/laptop display resolutions but to consider the
common desktop/laptop display resolutions over the course of several years when making this evaluation.
-
aangehouden
-
stopped by user request and not resumed until requested by user
- vooraf opgenomen
-
information that is not
live
- presentation
-
rendering of the
content in a form to be perceived by users
- primary education level
-
six year time period that begins between the ages of five and seven, possibly without any previous education
Opmerking: This definition is based on the International Standard Classification of Education
[UNESCO].
- process
-
series of user actions where each action is required in order to complete an activity
Voorbeeld 1:
Successful use of a series of Webpagina's on a shopping site requires users to view alternatief products, prices and offers, select products, submit an order, lever shipping information and lever payment information.
Voorbeeld 2:
An account registration page requires successful completion of a Turing test before the registration form can be accessed.
- programmatisch bepaald (programmatisch bepaalbaar)
-
determined by software from author-supplied data provided in a
way that different
user agents, including
hulptechnologieën, can extract and present this information to users in different modalities
Voorbeeld 1:
Determined in a markup language from elements and attributes that are accessed directly by commonly available hulptechnologie.
Voorbeeld 2:
Determined from technologiegebonden data structures in a non-markup language and exposed to hulptechnologie via an accessibility
API that is supported by commonly available hulptechnologie.
- programmatisch bepaald link context
-
additional information that can be
programmatisch bepaald from
relationships with a link, combined with the link text, and presented to users in different modalities
Voorbeeld: In HTML, information that is programmatisch bepaalbaar from a link in English includes text that is in the same paragraph, list, or table cell as the link or in a table header cell that is associated with the table cell that contains the link.
Opmerking: Since screen readers interpret punctuation, they can also lever the context from the current sentence, when the focus is on a link in that sentence.
- programmatisch set
-
set by software using methods that are supported by user agents, including hulptechnologieën
- zuivere decoratie
-
serving only an aesthetic purpose, providing no information, and having no functionaliteit
Opmerking: Text is only zuiver decoratiefif the words can be rearranged or substituted without changing their purpose.
Voorbeeld: The cover page of a dictionary has random words in very light text in the background.
- real-time event
-
event that a) occurs at the same time as the viewing and b) is not completely generated by the content
Voorbeeld 1:
A Webcast of a live performance (occurs at the same time as the viewing and is not vooraf opgenomen).
Voorbeeld 2:
An on-line auction with people bidding (occurs at the same time as the viewing).
Voorbeeld 3:
Live humans interacting in a virtual world using avatars (is not completely generated by the content and occurs at the same time as the viewing).
- relationships
-
meaningful associations between distinct pieces of content
- relative luminance
-
the relative brightness of any point in a kleurenpace, normalized to 0 for darkest black and 1 for lightest white
Opmerking 1:
For the sRGB kleurenpace, the relative luminance of a kleur is defined as L = 0.2126 * R + 0.7152 * G + 0.0722 * B where R, G and B are defined as:
-
if RsRGB <= 0.03928 then R = RsRGB/12.92 else R = ((RsRGB+0.055)/1.055) ^ 2.4
-
if GsRGB <= 0.03928 then G = GsRGB/12.92 else G = ((GsRGB+0.055)/1.055) ^ 2.4
-
if BsRGB <= 0.03928 then B = BsRGB/12.92 else B = ((BsRGB+0.055)/1.055) ^ 2.4
and RsRGB, GsRGB, and BsRGB are defined as:
-
RsRGB = R8bit/255
-
GsRGB = G8bit/255
-
BsRGB = B8bit/255
The "^" character is the exponentiation operator. (Formula taken from
[sRGB] and
[IEC-4WD]).
Opmerking 2:
Almost all systems used today to view Webcontent assume sRGB encoding. Unless it is known that another kleur space will be used to process and display the content, authors should evaluate using sRGB kleurenpace. If using other kleur spaces, see
Succescriterium xx begrijpen 1.4.3.
Opmerking 3:
If dithering occurs after delivery, then the source kleur value is used. For kleuren that are dithered at the source, the average values of the kleuren that are dithered should be used (average R, average G, and average B).
Opmerking 4:
Tools are available that automatically do the calculations when testing contrast and flash.
Opmerking 5:
A MathML version of the relative luminance definition is available.
- relied upon (technologieën that are)
-
the content would not
conform if that
technologie is turned off or is not supported
- role
-
text or number by which software can identify the function of a component within Webcontent
Voorbeeld: A number that indicates whether an image functions as a hyperlink, command button, or check box.
- same functionaliteit
-
same result when used
Voorbeeld: A submit "search" button on one Webpagina and a "find" button on another Webpagina may both have a field to enter a term and list topics in the Web site related to the term submitted. In this case, they would have the same functionaliteit but would not be labeled consistently.
- same relative order
-
same position relative to other items
Opmerking: Items are considered to be in the same relative order even if other items are inserted or removed from the original order. Bijvoorbeeld, expanding navigation menus may insert an additional niveau of detail or a secondary navigation section may be inserted into the reading order.
- satisfies a succescriterium
-
the succescriterium does not evaluate
to 'false' when applied to the page
- section
-
A self-contained portion of written content that deals with one or more related topics or thoughts
Opmerking: A section may consist of one or more paragraphs and include graphics, tables, lists and sub-sections.
- set of Webpagina's
-
collection of
Webpagina's that share a common purpose and that are created by the same
author, group or organization
Opmerking: Different language versions would be considered different sets of Webpagina's.
- sign language
-
a language using combinations of movements of the hands and arms, facial expressions, or
body positions to convey meaning
- sign language interpretation
-
translation of one language, generally a spoken language, into a
sign language
Opmerking:
True sign languages are independent languages that are unrelated to the spoken language(s) of the same country or region.
- specific sensorieel experience
-
a sensorieel experience that is not zuiver decoratiefand does not primarily convey important information or perform a function
Voorbeeld:
Examples include a performance of a flute solo, works of visual art etc.
- structure
-
The way the parts of a
Webpagina
are organized in relation to each other; and
-
The way a collection of
Webpagina's is organized
- supplemental content
-
additional
content that illustrates or clarifies the primary content
Voorbeeld 1:
An audio version of a
Webpagina.
Voorbeeld 2:
An illustration of a complex
process.
Voorbeeld 3:
A paragraph summarizing the major outcomes and recommendations made in a research study.
- gesynchroniseerde media
-
audio or
video gesynchroniseerde with another
format for presenting information and/or with
gesynchroniseerde interactive components, unless the media is a
media alternatief for text that is clearly labeled as such
- technologie (Webcontent)
-
mechanism for encoding instructions to be rendered, played or executed by
user agents
Opmerking 1:
As used in these Richtlijnen "Web Technology" and the word "technologie" (when used alone) both refer to Webcontent Technologies.
Opmerking 2:
Webcontent technologieën may include markup languages, data formats, or programming languages that authors may use alone or in combination to creëer end-user experiences that range from static Webpagina's to gesynchroniseerde media presentaties to dynamic Web applications.
Voorbeeld: Some common examples of Webcontent technologieën include
HTML,
CSS,
SVG,
PNG,
PDF, Flash, and JavaScript.
- tekst
-
sequence of characters that can be
programmatisch bepaald, where the sequence is expressing something in
human language
- tekstalternatief
-
Text that is programmatisch associated with
non-text content or referred to from text that is programmatisch associated with non-text content. programmatisch associated text is text whose location can be programmatisch bepaald from the non-text content.
Voorbeeld: An image of a chart is described in text in the paragraph after the chart. The short tekstalternatief for the chart indicates that a beschrijving follows.
- used in an unusual or restricted way
-
words used in such a way that requires users to know exactly which definition to apply in order to understand the content correctly
Voorbeeld: The term "gig" means something different if it occurs in a discussion of music concerts than it does in article about computer hard drive space, but the appropriate definition can be determined from context. By contrast, the word "text" is used in a very specific way in WCAG 2.0, so a definition is supplied in the glossarium.
- user agen
t
-
any software that retrieves and presents Webcontent for users
Voorbeeld: Web browsers, media players, plug-ins, and other programs – including
hulptechnologieën
– that help in retrieving, rendering, and interacting with Webcontent.
- user-controllable
-
data that is intended to be accessed by users
Opmerking: This does not refer to such things as Internet logs and search engine monitoring data.
Voorbeeld: Name and address fields for a user's account.
- user interface component
-
a part of the content that is perceived by users as a single control for a distinct function
Opmerking 1:
Multiple user interface components may be implemented as a single programmatic element. Components here is not tied to programming technieken, but rather to what the user perceives as separate controls.
Opmerking 2:
User interface components include form elements and links as well as components generated by scripts.
Voorbeeld: An applet has a "control" that can be used to move through content by line or page or random access. Since each of these would need to have a name and be settable independently, they would each be a "user interface component."
- video
-
the technologie of moving or sequenced pictures or images
Opmerking: Video can be made up of animated or photographic images, or both.
- video-only
-
a
gesynchroniseerde presentatie that contains only
video (no
audi
o and no interaction)
- viewport
-
object in which the user agent presents content
Opmerking 1:
The
user agent
presents content through one or more viewports. Viewports include windows, frames, loudspeakers, and virtual magnifying glasses. A viewport may contain another viewport (e.g., nested frames). Interface components created by the user agent such as prompts, menus, and alerts are not viewports.
Opmerking 2:
This definition is based on
User Agent Accessibility Richtlijnen 1.0 Glossarium.
- visually customized
-
the font, size, kleur, and background can be set
- Webpagina
-
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
Opmerking 1:
Although any "other resources" would be rendered together with the primary resource, they would not necessarily be rendered simultaneously with each other.
Opmerking 2:
For the purposes of conformiteit with these Richtlijnen, a resource must be "non-embedded" within the scope of conformiteit to be considered a Webpagina.
Voorbeeld 1:
A Web resource including all embedded images and media.
Voorbeeld 2:
A Web mail program built using Asynchronous JavaScript and XML (AJAX). The program lives entirely at http://example.com/mail, but includes an inbox, a contacts area and a calendar. Links or buttons are provided that cause the inbox, contacts, or calendar to display, but do not change the URI of the page as a whole.
Voorbeeld 3:
A customizable portal site, where users can choose content to display from a set of different content modules.
Voorbeeld 4:
When you enter "http://shopping.example.com/" in your browser, you enter a movie-like interactive shopping environment where you visually move around in a store dragging products off of the shelves around you and into a visual shopping cart in front of you. Clicking on a product causes it to be demonstrated with a specification sheet floating alongside. This might be a single-page Web site or just one page within a Web site.