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Wikipedia:Manual of Style/Accessibility

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Web accessibilityis the goal of making web pages easier to navigate and read. While this is primarily intended to assist those withdisabilities,it can be helpful to all readers. We aim to adhere toWeb Content Accessibility Guidelines2.1,[a]on which the following suggestions are based. Pages adhering to them are easier for everyone to read and edit.

Article structure[edit]

A standardized structure of articles improves accessibility, because it enables users to expect contents to be in a specific part of the page. For example, if a blind user is searching for disambiguation links and doesn't find any at the top of the page, they will know that there aren't any and they don't have to read the whole page to find that out.

Standardization is already a habit on Wikipedia, thus the guidelines to follow are simplyWikipedia:Manual of Style/LayoutandWikipedia:Manual of Style/Lead section § Elements.

Headings[edit]

Headings should be descriptive and in a consistent order asdefined in the Manual of Style.

Nest headings sequentially, starting with level 2 (==), then level 3 (===) and so on. (Level 1 is the auto-generated page title.) Do not skip parts of the sequence, such as selecting levels for emphasis; this is not the purpose of headings.

For purposes of readability for editors with poor vision—insource editoronly—a single blank line may be added beneath each heading, but not more than one; more than one blank line beneath a section heading will cause extra space to be visible on the rendered page. Consideration should also be given to how a single blank white line beneath section headings may appear on a small screen for a particular article, as many editors use mobile devices to edit, and having a single blank line beneath the heading may actually detract from the readability for these editors, for some articles.

Examples of correct and incorrect use of nested headings
Correct Random/chaotic Skipping levels

[Article lead here]
==Section==[level 2]
===Sub-section===[3]
==Section==[2]
===Sub-section===[3]
====Sub-sub-section====[4]
==Section==[2]

[Article lead here]
====Section?====[4]
===Section?===[3]
==Section?==[2]
==Section?==[2]
====Section?====[4]
===Section?===[3]

[Article lead here]
[Level-2 section missing here]
===Section?===[3]
==Section==[2]
[Level-3 sub-section missing here]
====Sub-section?====[4]
==Section==[2]

Do not make pseudo-headings by abusing semicolon markup (reserved fordescription lists) and try to avoid using bold markup. Screen readers and other assistive technology can only use headings that have heading markup for navigation. If you want to reduce the size of the table of contents (TOC), use{{TOC limit}}instead. In cases where{{TOC limit}}cannot be used because of lower-level headings elsewhere in the article, then using bold for the sub-sub-sub headings causes the least annoyance for screen reader users. Using a pseudo heading at all means you have exhausted all other options. It is meant as a rarity.

Examples of acceptable and incorrect use of pseudo-headings and description lists
Acceptable Incorrect

[Article lead here]
==Section==[level 2]
===Sub-section===[3]
'''Pseudo-heading'''
==Section==[2]
===Sub-section===[3]
====Sub-sub-section====[4]
;A term followed by
:at least one definition or at least one description list item
:and additional optional items, forming a list

[Article lead here]
==Section==[level 2]
===Sub-section===[3]
;Pseudo-heading
==Section==[2]
===Sub-section===[3]
<small>==Sub-sub-section==</small>[2]

Floating elements[edit]

In the wikicode, floating elements (including images) should be placedinsidethe section they belong to; do not place the image at the end of the previous section. (Depending on platform, "stacking" of several images alongside a relatively small amount of text may cause a particular image to be pushed down to a later section. However, this is not an accessibility issue, as screen readers always read each image'salt=out at the point where the image iscoded).

Resolution[edit]

Wikipedia articles should be accessible to readers using devices with small screens such asmobile devices,or to readers using monitors with a low resolution. On desktop, this is sometimes an issue in articles withmultiple images on both sides of the screen;although lower resolutions will tend to stretch paragraphs vertically, moving images apart in that direction, be careful not to add images or other floating content on both sides of the screen simultaneously. Large tables and images can also create problems; sometimes horizontal scrolling is unavoidable, but consider restructuring wide tables to extend vertically rather than horizontally.

Text[edit]

By default, mostscreen readersdo not indicate presentational text attributes (bold, italic, underline, monospace, strikethrough) or even semantic text attributes (emphasis, importance, text deletion), so struck-out text is read normally along with any other text. (Editors using screen readers who participate in Wikipedia policy and deletion debates are advised to turn on notifications about text attributes when doing so, as struck text is very common in Wikipedia-internal discussions.)

Sincestrikethroughis normally ignored by screen readers, its rare use in articles (e.g., to show changes in a textual analysis) will cause accessibility problems and outright confusion if it is the only indication used. This applies to both the<s>and<del>elements (along with their corresponding<ins>,usually visually rendered as underlined), as well as templates that use them. Do not use strikethrough to object to content you think is inappropriate or incorrect. Instead, comment it out with<!--and-->,remove it entirely, or use aninline cleanup/dispute template,and raise the matter on the talk page.

Screen readers have widely varying support for characters outsideLatin-1andWindows-1252and it is not safe to assume how any given character in these ranges will be pronounced. If they are not recognized by the screen reader or speech synthesizer, they may be pronounced as a question mark or omitted entirely from the speech output.

  1. Provide atransliterationfor all text in a non-Latin writing system where the non-Latin character is important in the original context such as names, places, things etc. This functionality is available in templates that signify non-Latin-script languages and can also be found in templates such as{{Transliteration}};these templates also have other accessibility benefits (see the"Other languages" sectionbelow).
  2. Do not use possibly unpronounceable symbols such as ♥ (aheart symbol); use images with alt text instead.[1]
  3. Symbols that cause problems for screen readers may already have templates created to produce an image and alt text. An example is the dagger template{{}}(seeCategory:Single-image insertion templatesfor more).[needs update]

The sequence of characters must be sufficient to convey semantic aspects of the text (and, preferably, other similar forms of content); reliance on custom "special symbols" distinguishable only by CSS properties or wiki markup is not acceptable.

Do not use techniques that require interaction to provide information, such as tooltips or any other "hover" text. Abbreviations are exempt from these requirements, so the{{abbr}}template (a wrapper for the<abbr>element) may be used to indicate the long form of an abbreviation (including an acronym or initialism).

Do not insert line breaks within a sentence, since this makes it harder to edit with ascreen reader.A single line break may follow a sentence, which may help some editors.

Font size[edit]

Reduced or enlarged font sizes should be used sparingly, and are usually done with automated page elements such as headings, table headers, and standardized templates. Size changes are specified as apercentageof the original font size and not as an absolute size in pixels or point size. Relative sizes increase accessibility for visually impaired users by allowing them to set a large(r) default font size in their browser settings. Absolute sizes deny users such ability.

Avoid using smaller font sizes within page elements that already use a smaller font size, such as most text withininfoboxes,navboxes,andreferences sections.[b]This means that<small>...</small>tags, and templates such as{{small}}and{{smalldiv}},should not be applied toplain textwithin those elements. In no case should the resulting font size of any text drop below 85% of the page's default font size. Note that the HTML<small>...</small>tag has a semantic meaning offine printor side comments;[2]do not use it for stylistic changes.

Fractions[edit]

Apart from the exceptions explained atWP:Manual of Style/Dates and numbers § Fractions,do not useprecomposed fractioncharacters such as½(deprecated markup:&frac12;or&#189;). This is because some precomposed fractions may not work withscreen readersor may be unreasonably difficult for readers with impaired vision to decipher. Use{{Fraction}}which produces fractions in the form34.(Forscientific and mathematical text,use{{sfrac}}which produces fractions in the form3/4.)

Other languages[edit]

By default, English Wikipedia articles state explicitly to the browser that they are written wholly in English. Text in a language other than English should be tagged as such, typically with a template like{{lang}}(or one of its derivatives). This wraps the text in anIETF language tag,which specifies the language and script. For example:

  • Red XN''Assemblée nationale''is simply italicized, and does not specify that it is French-language text. Most screen readers attempting to handle this will sound ridiculous or confusing.
  • Green tickY{{lang|fr|Assemblée nationale}}renders asAssemblée nationale,which is italicized by default and will allow screen readers to select a French-language voice.
  • Green tickY{{lang-fr|Assemblée nationale}}French:Assemblée nationale– This is similar to the above, but uses a template specifically designed for French-language text.

Rationale:Among other uses, specifying the language of text with{{lang}}allows speech synthesizers to select a voice capable of correctly reading out the text.[3]

IETF language tags specify the language of text according to theISO 639specification, but also which script is being used to write the language:

  • Green tickY{{lang|sr-Cyrl|Народна скупштина}}Народна скупштина
  • Green tickY{{lang|sr-Latn|Narodna skupština}}Narodna skupština– Serbian can typically be written using either the Latin or Cyrillic script.
  • Red XN{{lang|ja|Kokumin gikai}}– By default, it is expected that Japanese text has been written using the native writing system, whose rules may treat some characters differently.
  • Green tickY{{lang|ja-Latn|Kokumin gikai}}specifies Japanese written with the Latin Alpha bet—e.g.rōmaji.
  • Green tickY{{transliteration|ja|Kokumin gikai}}is equivalent to the above.

Without specifying a script, IETF tags assume the most common script used to write a given language. Therefore,transliterationsshould specify use of Latin script by appending-Latnto the language code, or by using the equivalent{{transliteration}}template.Wikipedia has a number oflanguage-specific templatessuch as{{lang-zh}}and{{nihongo}},which provide language-specific functionality to editors, such as the ability to easily display several transliterations with one template. Not every language has its own template, but using one may be helpful to streamline wikitext, instead of cluttering paragraphs with instances of{{lang}}and{{transliteration}}.

It is usually unnecessary to specify italics in addition to the{{lang}}or{{[[Template:lang-xx|lang-xx]]}}templates, which italicize text using the Latin Alpha bet by default. If text should not be italicized, such as with the names of places or people, the parameter|italic=unsetmay be added.[c]As outlined inMOS:FOREIGN,text using a non-Latin script should almost never be italicized or bolded.

Phonetic transcriptions or pronunciation guides should use{{IPA}},{{respell}},or another suitable template.{{PIE}}is used forProto-Indo-European.

Links[edit]

  1. Create good link descriptions, especially for external links (avoid "click here!","this").[4][5]
  2. Do not useUnicodecharacters as icons; use an icon with alt text instead. For example, a character like "→" cannot be reproduced into useful text by somescreen readers.
  3. UseTemplate:Visible anchorswhereDestination highlightinghelps the partially sighted to locate more easily the link target on the destination page.

Color[edit]

Two screenshots of the same highly textual user interface. The top one uses red, green, and blue; the bottom one uses nearly the same color for red and green, so that the red text becomes nearly invisible in its green background.
A pair of screenshots showing the effects of red/green color-blindness on legibility

Colorsare most commonly found in Wikipedia articles withintemplatesandtables.For technical assistance on how colors are used, seeHelp:Using colors.

Articles (and other pages) that use color should keep accessibility in mind, as follows:

  • Ensure that color is not the only method used to communicate important information. Especially, do not use colored text or background unless its status is also indicated using another method, such as anaccessible symbolmatched to a legend, orfootnote labels.Otherwise,blindusers or readers accessing Wikipedia through a printout or device without a color screen will not receive that information.
  • Links should clearly be identifiable as a link to our readers.
  • Some readers of Wikipedia are partially or fullycolor-blindor visually impaired. Ensure the contrast of the text with its background reaches at leastWeb Content Accessibility Guidelines(WCAG) 2.0's AA level, and AAA level when feasible (see WCAG's"Understanding SC 1.4.3: Contrast (Minimum)"). To use named CSS colors for text on a white background, refer toWikipedia:Manual of Style/Accessibility/CSS colors for text on whitefor recommended colors. For other usage, here is a selection of tools that can be used to check that the contrast is correct:
    • You can use a few online tools to check color contrasts, including: theWebAIMonlinecontrast checker,or theWhoCanUsesite, orSnook's Color Contrast Check.
      • Several other tools exist on the web, but check if they are up-to-date before using them. Several tools are based on WCAG 1.0's algorithm, while the reference is now WCAG 2.0's algorithm. If the tool doesn't specifically mention that it is based on WCAG 2.0, assume that it is outdated.
    • The Wikimedia Foundation Design teamhas provided a color palettewith colors being marked towards level AA conformance. It is used for all user-interface elements across products and in the main Wikimedia themes, desktop and mobile. However, it does not consider linked text.
    • The table atWikipedia:Manual of Style/Accessibility/Colorsshows the results for 14 hues of finding the darkest or lightest backgrounds that are AAA-compliant against black text, white text, linked text and visited linked text.
    • Google Chrome has acolor contrast debuggerwith visual guide and color-picker.
    • The downloadable softwareColor Contrast Analyserenables you to pick colors on the page, and review their contrast thoroughly. However, be sure to only use the up-to-date "luminosity" algorithm, and not the "color brightness/difference", which is outdated.
  • Additional tools can be used to help produce graphical charts and color schemes for maps and the like. These tools are not accurate means to review contrast accessibility, but they can be helpful for specific tasks.
    • Paletton(previously Color Scheme Designer) helps to choose a good set of colors for a graphical chart.
    • Color Brewer 2.0provides safe color schemes for maps and detailed explanations.
    • Light qualitative color schemeprovides a set of nine colors that work for color-blind users and with black text labels (among other palettes).
    • There are some tools for simulating color-blind vision:Toptal ColorFilter(webpage analysis) andCoblis Color-blindness Simulator(local file analysis). There are also browser extensions for webpage analysis:NoCoffee(Firefox)
    • A very simple open-source tool that can be helpful for choosing contrasting colors isColor Oracle,a "free color blindness simulator for Windows, Mac and Linux". It lets you view whatever is on your screen as it would be seen by someone with one of three types of color-blindness or in greyscale.
  • If an article overuses colors, and you don't know how to fix it yourself, you can ask for help from other editors. Place{{Overcolored}}or{{Overcoloured}}at the top of the article.
Contrast ratios of web safe colours vs black (top row) and white (bottom) or vice versa, with contours at 3 (red), 4.5 (green) and 7 (blue)

Block elements[edit]

Lists[edit]

Do not separate list items by leaving empty lines or tabular column breaks between them. This includes items in adescription list(a list made with a leading semicolon or colon, which is also how most talk-page discussions are formatted) or anordered listorunordered list.Lists are meant to group elements that belong together, butMediaWikiwill interpret the blank line as the end of one list and start a new one. Excessive double line breaks also disruptscreen readers,which will announce multiple lists when only one was intended, and therefore may mislead or confuse users of these programs. Such improper formatting can also more than triple the length of time it takes them to read the list.

Likewise, do not switch between initial list marker types (colons, asterisks or hash signs) in one list. When indenting in reply to a post that starts with any mix of colons and asterisks and sometimes hash signs, it is necessary to copy whatever series of those characters was used above, and append one more such character. Alternatively, simplyoutdentand start a new discussion (i.e., a new HTML list).

Examples:

checkYIn a discussion, do this,

*Support. I like this idea. —User:Example
**Question: What do you like about it? —User:Example2
***It seems to fit the spirit of Wikipedia. —User:Example

checkYOr, in an unbulleted discussion, this,

:Support. I like this idea. —User:Example
::Question: What do you like about it? —User:Example2
:::It seems to fit the spirit of Wikipedia. —User:Example

checkYSuppressing the bullet on a reply is also acceptable,

*Support. I like this idea. —User:Example
*:Question: What do you like about it? —User:Example2
*::It seems to fit the spirit of Wikipedia. —User:Example

☒NBut don't switch type from bullet list to description list,

*Support. I like this idea. —User:Example
::Question: What do you like about it? —User:Example2

☒Nnor switch from bullet list to mixed type,

*Support. I like this idea. —User:Example
:*Question: What do you like about it? —User:Example2

☒NLeaving blank lines between list items is generally bad practice,

*Support. I like this idea. —User:Example

**Question: What do you like about it? —User:Example2

☒NAs is jumping more than one level,

*Support. I like this idea. —User:Example
***Question: What do you like about it? —User:Example2

☒NThis is generally discouraged:

:Support. I like this idea. —User:Example
:*Question: What do you like about it? —User:Example2

This injection of a bullet unnecessarily adds to list complexity and makes people more likely to use the wrong indentation levels in replies.

Multiple paragraphs within list items[edit]

Normal MediaWiki list markup is unfortunately incompatible with normal MediaWiki paragraph markup.

checkYTo put multiple paragraphs in a list item, separate them with{{pb}}:

*This is one item.{{pb}}This is another paragraph within this item.
*This is another item.

checkYThis can also be done with explicit HTML markup for paragraphs (note the closing</p>tag):

*This is one item.<p>This is another paragraph within this item.</p>
*This is another item.

checkYIn both cases, this must be done on a single code line. However, you can optionally use the trick of wrapping a code line break in an HTML comment (which suppresses it as an output line break), to separate paragraphs better in code view:

*This is one item.<!--
--><p>This is another paragraph within this item.</p>
*This is another item.

checkYThis technique can be used for various forms of block-inclusion within a list item (because list items are technically block elements, which can contain other block elements):

*This is one item.<!--
--><p>This is another paragraph within this item, and we're going to quote someone:</p><!--
-->{{talk quote block|Imagine a world in which every single person on the planet is given free access to the sum of all human knowledge.|Jimbo}}<!--
--><p>This is a closing paragraph within the same list item.</p>
*This is another item.

Be aware that not every fancy template can be used in this manner (e.g. some decorative quotation templates are table-based, and the MediaWiki parser will not handle such markup as being inside a list item).

See alsoWP:Manual of Style/Glossariesfor rich but accessible markup of complexdescription/definition/association lists.

☒NDo not use line breaks to simulate paragraphs, because they have different semantics:

*This is one item.<br/>This is the same paragraph, with a line break before it.
*This is another item.

Line-break tags are for wrappingwithina paragraph, such as lines of a poem or of a block of source code. See also the<poem>and<syntaxhighlight>MediaWiki tags.

☒NDefinitely do not attempt to use a colon to match the indentation level, since (as mentioned above) it produces three separate lists:

*This is one item.
:This is an entirely separate list.
*This is a third list.

checkYAlternatively, you can use one of theHTML list templatesto guarantee grouping. This is most useful for including block elements, such as formatted code, in lists:

{{bulleted list
|1=This is one item:
<pre>
This is some code.
</pre>
This is still the same item.
|2=This is a second item.
}}

But this technique is not used on talk pages.

Indentation[edit]

An accessible approach to indentation is the template{{block indent}}for multi-line content; it usesCSSto indent the material. For single lines, a variety of templates exist, including{{in5}}(a universal template, with the same name on all Wikimedia sites); these indent with various whitespace characters.Do not abusethe<blockquote>...</blockquote>element or templates that use it (such as{{blockquote}}) for visual indentation; they are only for directly quoted material. The{{block indent}}generic alternative was created for such non-quote cases, so please use it.

A colon (:) at the start of a line marks that line in the MediaWiki parser as the<dd>part of an HTMLdescription list(<dl>).[d]The visual effect in most Web browsers is to indent the line. This is used, for example, to indicate replies in a threaded discussion on talk pages. However, this markup alone is missing the required<dt>(term) element of a description list, to which the<dd>(description/definition) pertains. As can be seen by inspecting the code sent to the browser, this results in broken HTML (i.e. it failsvalidation[6]). The result is that assistive technology, such as screen readers, will announce a description list that does not exist, which is confusing for any visitor unused to Wikipedia's broken markup. This is not ideal for accessibility,semantics,orreuse,but is currently commonly used, despite the problems it causes for users of screen readers.

Blank lines mustnotbe placed between colon-indented lines of text– especially in article content. This is interpreted by the software as marking the end of a list and the start of a new one.

If space is needed, there are two approaches, which will have different results for screen readers:

The first is to add a blank line with the same number of colons on it as those preceding the text above and below the blank line. This is appropriate when two editors are making comments immediately after each other at the same indentation level. For instance:

:I completely agree. —User:Example
:
: I'm unconvinced. Is there a better source available? –User:Example2

This will tell the screen reader that this is two list items (the blank one will be ignored).

The second approach, for when the material is meant to be a single comment (or other list item, e.g. in article text) is to use new-paragraph markup on the same output line (see previous section for advanced techniques in this, to include complex content blocks):

:Text here.{{pb}}More text. —User:Example3

To display a mathematical formula or expression on its own line, it is recommended that<math display= "block" >1 + 1 = 2</math>be used instead of:<math>1 + 1 = 2</math>.

Vertical lists[edit]

Bulleted vertical lists[edit]

For bulleted vertical lists, do not separate items by leaving blank lines between them. Instead, use the{{pb}}template or<p>HTML markup.(A blank line before the start of a list, or after the end of the list, causes no problems.)

The problem with blank lines in the middle of a list is that, if list items are separated by more than one line break, theHTMLlist will be ended before the line break, and another HTML list will be opened after the line break. This effectively breaks what is seen as one list into several smaller lists for those usingscreen readers.For example, for the coding:

* White rose
* Yellow rose

* Pink rose

* Red rose

the software partially suppresses line spaces and therefore it looks like this:

  • White rose
  • Yellow rose
  • Pink rose
  • Red rose

but will be read by a screen reader as: "List of 2 items: (bullet) White rose, (bullet) Yellow rose, list end. List of 1 items: (bullet) Pink rose, list end. List of 1 items: (bullet) Red rose, list end."

Do not separate list items with line breaks (<br />). Use{{plainlist}}/{{unbulleted list}}if the list is to remain vertical; or consider{{flatlist}}/{{hlist}}if the list could be better rendered horizontally (inline) as described in the following two sections.

Unbulleted vertical lists[edit]

For unbulleted lists running down the page, the templates{{plainlist}}and{{unbulleted list}}are available, to improve accessibility and semantic meaningfulness by marking up what is clearly a list rather than including<br />line breaks, which should not be used—see above. They differ only in the wiki-markup used to create the list. Note that because these are templates, the text of each list item cannot contain the vertical bar symbol (|) unless it is replaced by{{!}}or is contained within<nowiki>...</nowiki>tags. Similarly it can't contain the equals sign (=), unless replaced with{{=}}or contained within<nowiki>...</nowiki>,though you can bypass this by naming the parameters (|1=,|2=etc.). If this becomes too much of a hassle, you may be able to use the variant with{{endplainlist}}instead. Inside a reference, you may need{{unbulleted list citebundle}}instead.

Example of plainlist
Wikitext Renders as
{{plainlist |
* White rose
* Yellow rose
* Pink rose
* Red rose
}}
  • White rose
  • Yellow rose
  • Pink rose
  • Red rose
Example of unbulleted list
Wikitext Renders as
{{unbulleted list
| White rose
| Yellow rose
| Pink rose
| Red rose
}}
  • White rose
  • Yellow rose
  • Pink rose
  • Red rose

Alternatively, in templates such asnavboxesand the like, or any suitable container, such lists may be styled with the class "plainlist",thus:

  • | listclass = plainlistor
  • | bodyclass = plainlist

Ininfoboxes,the following may be used:

  • | rowclass = plainlistor
  • | bodyclass = plainlist

See alsoWP:Manual of Style/Lists § Unbulleted lists.

Other vertical lists[edit]

The above blank-line issues also affectnumbered lists,using#markup, and the list numbering will reset after the line break. The list-breakage problem of blank lines also applies todescription (definition, association) lists,using;and:markup; that type of list can have line breaks in it if insteadcreated with the glossary templates.

Horizontal lists[edit]

For lists running across the page, and in single rows ininfoboxesand other tables, the templates{{flatlist}}and{{hlist}}(for "horizontal list" ) are available to improve accessibility and semantic meaningfulness. This feature makes use of the correct HTML markup for each list item, rather than including bullet characters which, for example, are read out (e.g., "dot cat dot dog dot horse dot..." ) by the assistive software used by people who are blind. The templates differ only in the wiki-markup used to create the list. Note that when text is being passed to these (or any other) templates, the vertical bar character (|) should beescapedwith{{!}}.

Example of flatlist
Wikitext Renders as
{{flatlist |
* White rose
* Red rose
** Pink rose
* Yellow rose
}}
  • White rose
  • Red rose
    • Pink rose
  • Yellow rose
Example of hlist
Wikitext Renders as
{{hlist
| White rose
| Red rose
| Pink rose
| Yellow rose
}}
  • White rose
  • Red rose
  • Pink rose
  • Yellow rose

Alternatively, in templates such asnavboxesand the like, or any suitable container, such lists may be styled with the classhlist,thus:

  • | listclass = hlistor
  • | bodyclass = hlist

Ininfoboxes:

  • | rowclass = hlistor
  • | bodyclass = hlist

may be used.

List headings[edit]

Improper use of a semicolon to bold a "fake heading" before a list (figure 1) creates alist gap,and worse. The semicolon line is a one-item description list, with no description content, followed by a second list.

Instead, use heading markup (figure 2).

☒N1. Incorrect

;Noble gases
*Helium
*Neon
*Argon
*Krypton
*Xenon
*Radon

checkY2. Heading

== Noble gases ==
*Helium
*Neon
*Argon
*Krypton
*Xenon
*Radon

Tables[edit]

Screen readers and other web browsing tools make use of specific table tags to help users navigate the data contained within them.

Use the correct wikitable pipe syntax to take advantage of all the features available. Seemeta:Help:Tablesfor more information on the special syntax used for tables. Do not solely use formatting, either from CSS or hard-coded styles, to create semantic meaning (e.g., changing background color).

Manynavboxes,series templates,andinfoboxesare made using tables.

Avoid using<br />or<hr />tags in adjacent cells to emulate a visual row that isn't reflected in the HTML table structure. This is a problem for users of screen readers which read tables cell by cell, HTML row by HTML row, not visual row by visual row.

Data tables[edit]

Wikitext:

{|class="wikitable"
|+caption text
|-
!scope="col"|column header 1
!scope="col"|column header 2
!scope="col"|column header 3
|-
!scope="row"|row header 1
|data 1||data 2
|-
!scope="row"|row header 2
|data 3||data 4
|}

Produces:

caption text
column header 1 column header 2 column header 3
row header 1 data 1 data 2
row header 2 data 3 data 4
Caption (|+)
A caption is a table's title, describing its nature.[7]Data tables should always include a caption.
Row and column headers (!)
Like the caption, these help present the information in a logical structure to visitors.[8]The headers help screen readers render header information about data cells. For example, header information is spoken prior to the cell data, or header information is provided on request.[9]Because the row header and column header may be spoken before the data in each cell when navigating in table mode, it is necessary for the column headers and row headers touniquely identifythe column and row respectively.[10]
Scope of headers (!scope= "col" |and!scope= "row" |)
This clearly identifies a cell as a header for a column or row. Use!scope= "colgroup" colspan= "2" |if a column header spans a group of columns and!scope= "rowgroup" rowspan= "2" |if a row header spans a group of rows, adjusting the span count as needed. Headers can now be associated to corresponding cells.[11]

Wikipedia:Manual of Style/Accessibility/Data tables tutorialprovides detailed requirements about:

  1. Correct table captions
  2. Correct headers structure
  3. Complex tables
  4. Images and color
  5. Avoiding nested tables

Layout tables[edit]

Avoid using tables for visual positioning of non-tabular content. Data tables provide extra information and navigation methods that can be confusing when the content lacks logical row and column relationships. Instead, use semantically appropriate elements or<div>s, andstyleattributes.

When using a table to position non-tabular content, help screen readers identify it as a layout table, not a data table. Set arole= "presentation"attribute on the table, and do not set anysummaryattribute. Do not use any<caption>or<th>elements inside the table, or inside any nested tables. In wiki table markup, this means do not use the|+or!prefixes. Make sure the content's reading order is correct. Visual effects, such as centering or bold typeface, can be achieved with style sheets or semantic elements. For example:

{|role="presentation"
|-
|colspan="2"style="text-align: center; background-color: #ccf;"|<strong>Important text</strong>
|-
|The quick||brown fox
|-
|jumps over||the lazy dog.
|}
Important text
The quick brown fox
jumps over the lazy dog.

Images[edit]

  1. Images and icons that are not purely decorative should include analt attributethat acts as a substitute for the image for blind readers, search-spiders, and other non-visual users. If additional alt text is added, it should be succinct or refer the reader to the caption or adjacent text.(SeeWP:Manual of Style/Accessibility/Alternative text for imagesfor more information. For additional considerations about icons, seeWP:Manual of Style/Icons § Remember accessibility for people with visual impairment.)
  2. Inmost cases,images should include acaptionusing the built-in image syntax. The caption should concisely describe the meaning of the image and the essential information it is trying to convey.
  3. Avoid using images in place oftables or charts.Where possible, any charts or diagrams should have a text equivalent or should be well-described so that users who are unable to see the image can gain some understanding of the concept.
  4. Avoidsandwichingtext between two images or, unless absolutely necessary, usingfixed image sizes.
  5. Avoid indiscriminategalleriesbecause screen size and browser formatting may affect accessibility for some readers due to fragmented image display (e.g.). Articles with many images may time out on mobile versions of Wikipedia. Ideally, a page should have no more than 100 images (regardless of how small). SeeMediaWiki:Limit number of images in a page
  6. Avoid referring in text to images as being on the left or right. Image placement may be different for viewers of the mobile site, and is meaningless to people having pages read to them by assistive software. Instead, use captions to identify images.(SeeWP:Manual of Style/Images § References from article text.)
  7. Detailed image descriptions, where not appropriate for an article, should be placed on the image's description page, with a note saying that activating the image link will lead to a more detailed description.(SeeHelp:File description page § Image summary.)
  8. Images should be inside the section to which they are related (after the heading and anyhatnotes), and not in the heading itself nor at the end of the previous section. This ensures that screen readers will read, and the mobile site will display, the image (and its textual alternative) in the correct section.(SeeWP:Manual of Style/Images § Section.)
  9. This guideline includes alt text for LaTeX-formatted equations in<math>mode. SeeWikipedia:Manual of Style/Mathematics § Alt text
  10. Do not put images in headings;this includesiconsand<math>markup. Doing so can break links to sections and cause other problems.

Animations, video, and audio content[edit]

Animations[edit]

To be accessible, an animation (GIF– Graphics Interchange Format) should either:

  • Not exceed a duration of five seconds (which results in making it a purely decorative element)[12]or
  • Be equipped with control functions (stop, pause, play)[13]

This requires that GIFs with animations longer than five seconds be converted to video (to learn how, see the tutorialconverting animated GIFs to Theora OGG).

In addition, animationsmust notproduce more than three flashes in any one-second period. Content that flashes more than that limit is known to cause seizures.[14]

Video[edit]

Subtitles can be added to video, intimed textformat. There is a corresponding help page at:commons:Commons:Video § Subtitles and closed captioning.Subtitles are meant for the transcription of speech.

There is a need forclosed captionsfor the hearing impaired. As of November 2012 this is not possible, but this feature could be easily added and has been requested inbugzilla:41694.Closed captions are meant to be viewed instead of subtitles. Closed captions provide a text version of all important information provided through the sound. It can include dialogue, sounds (natural and artificial), the setting and background, the actions and expressions of people and animals, text or graphics.[15]Off-Wikipedia guides should be consulted for how to create closed captions.[16]

A text version of the video would also be needed for the blind, but as of November 2012 there is no convenient way to provide alt text for videos.[needs update]

Audio[edit]

Subtitles for speech, lyrics, dialogue, etc.[17]can easily be added to audio files. The method is similar to that of the video::commons:Commons:Video § Subtitles and closed captioning.

Styles and markup options[edit]

Best practice: wiki markup and CSS classes[edit]

In general, styles for tables and other block-level elements should be set using CSS classes, not with inline style attributes. The site-wide CSS inMediaWiki:Common.cssis more carefully tested to ensure accessibility (e.g. sufficient color contrast) and compatibility with a wide range of browsers. Moreover, it allows users with very specific needs to change the color schemes in their own style sheet (Special:MyPage/skin.css,or their browser's style sheet). For example, a style sheet atWikipedia:Style sheets for visually impaired usersprovides higher contrast backgrounds fornavboxes.The problem is that when the default site-wide classes are overridden, it makes it far more difficult for an individual to choose their own theme.

It also creates a greater degree of professionalism by ensuring a consistent appearance between articles and conformance to a style guide.

Regarding accessibility, deviations from standard conventions may be toleratedso long as they are accessible.Members of the accessibility project have ensured that the default style is accessible. If some template or specific color scheme deviates from the standard, its authors should make sure that it meets accessibility requirements such as providing enoughcolor contrast.For instance, theinfoboxandnavboxrelating to a sport team might use a yellow and red color scheme, to tie in with the colors of the team livery. In this case, dark red links on light yellow provide enough color contrast, and thus would be accessible, while white on yellow or black on red would not.

In general, articles should usewiki markupin preference to the limited set ofallowed HTML elements.In particular, do not use the HTML style elements<i>and<b>to format text; it is preferable to use Wiki-markup''or'''for purely typographic italicization and boldfacing, respectively, and usesemantic markuptemplates or elements for more meaningful differences. The<font>element should also be avoided in article text; use{{em}},{{code}},{{var}},and our othersemantic markup templatesas needed, to emphasize logical differences not just visual ones. Use the {{subst:resize}}, {{subst:small}}, and {{subst:Large}} templates to change font size, rather than setting it explicitly with CSS style attributes likefont-sizeor deprecated style elements like<big />.Of course there are natural exceptions; e.g., it may be beneficial to use the<u>...</u>element to indicate something like an example link that isn't really clickable, but underlining is otherwise generallynot used in article text.

Users with limited CSS or JavaScript support[edit]

Auto-collapsed (pre-collapsed) elementsshould not be used to hide contentin the article's main body.

Wikipedia articles should be accessible to readers using browsers and devices that have limited or no support forJavaScriptorCascading Style Sheets,which is referred to as "progressive enhancement"in web development. Remember thatWikipedia content can be reused freelyin ways we cannot predict as well as accessed directly via older browsers. At the same time, it is recognized that it is impossible to provide the same quality of appearance to such users without unnecessarily avoiding features that would benefit users with more capable browsers. As such, features that would cause content to be hidden or corrupted when CSS or JavaScript is unavailable must not be used. However, consideration for users without CSS or JavaScript should extend mainly to making sure that their reading experience ispossible;it is recognized that it will inevitably beinferior.

Note that mobile versions of the website do not support collapsing, so any collapsible content will automatically be uncollapsed.

To accommodate these considerations, test any potentially disruptive changes with JavaScript or CSS disabled. In Firefox or Chrome, this can be done easily with the Web Developer extension; JavaScript can be disabled in other browsers in the "Options" screen. Be particularly careful with inline CSS effects, which are not supported by several browsers, media, and XHTML versions.

In 2016, around 7% of visitors to Wikipedia did not request JavaScript resources.[18]

See also[edit]

Notes[edit]

  1. ^The previous version, WCAG 2.0, is also anISOstandard, ISO/IEC 40500:2012.
  2. ^The general font size for infoboxes and navboxes is 88% of the page's default. The general font size for reference sections is 90% of the page's default. Additional values can be found atMediaWiki:Common.css.
  3. ^Further details on this usage are available on the template documentation for{{lang}}.
  4. ^HTMLdescription listswere formerly calleddefinition listsandassociation lists.The<dl><dt>...</dt><dd>...</dd></dl>structure is the same; only the terminology has changed between HTML specification versions.

References[edit]

  1. ^"F26: Failure of Success Criterion 1.3.3 due to using a graphical symbol alone to convey information".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved29 December2011.
  2. ^"4.5.4 The small element".HTML Living Standard.Web Hypertext Application Technology Working Group.24 December 2023.Retrieved29 December2023.
  3. ^"H58: Using language attributes to identify changes in the human language".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved29 December2023.Accessibility level: AA.
  4. ^"G91: Providing link text that describes the purpose of a link".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved29 December2023.
  5. ^"F84: Failure of Success Criterion 2.4.9 due to using a non-specific link such as 'click here' or 'more' without a mechanism to change the link text to specific text".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved29 December2023.
  6. ^"Markup Validation Service: Check the markup (HTML, XHTML,...) of Web documents".validator.w3.org.v1.3+hg.World Wide Web Consortium.2017.RetrievedDecember 13,2017.The validator failure reported is "Error:Elementdlis missing a required child element. "
  7. ^"H39: Using caption elements to associate data table captions with data tables".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved29 December2023.Accessibility level: A.
  8. ^"H51: Using table markup to present tabular information".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved29 December2023.
  9. ^"4.9.10 The th element".HTML Living Standard.Web Hypertext Application Technology Working Group.24 December 2023.Retrieved29 December2023.
  10. ^"HTML Tables with JAWS".FreedomScientific.Freedom Scientific.Retrieved29 December2023.
  11. ^"H63: Using the scope attribute to associate header cells and data cells in data tables".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved24 December2023.
  12. ^"G152: Setting animated gif images to stop blinking after n cycles (within 5 seconds)".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved29 December2023.
  13. ^"G4: Allowing the content to be paused and restarted from where it was paused".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved29 December2023.
  14. ^"Guideline 2.3 Seizures: Do not design content in a way that is known to cause seizures".Web Content Accessibility Guidelines (WCAG) 2.0.World Wide Web Consortium.11 December 2008.Retrieved29 December2023.
  15. ^"G69: Providing an alternative for time based media".Techniques for WCAG 2.0.World Wide Web Consortium.Retrieved1 January2011.
  16. ^See:
  17. ^"G158: Providing an alternative for time-based media for audio-only content".Techniques for WCAG 2.0.World Wide Web Consortium.7 October 2016.Retrieved29 December2023.
  18. ^File:Browsers, Geography, and JavaScript Support on Wikipedia Portal.pdf;andFile:Analysis of Wikipedia Portal Traffic and JavaScript Support.pdf.

Further reading[edit]

External links[edit]