The Wikimedia Foundation Design team has provided a color palette with 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 at Wikipedia:Manual of Style/Accessibility/Colors shows 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.
Light qualitative colour scheme provides a set of 9 colours that work for color blind users and with black text labels (among other palettes).
There are some tools for simulating color-blind vision: toptal (webpage analysis) and coblis (local file analysis). There are also browser extensions for webpage analysis: Colorblinding (Chrome) NoCoffee (Chrome) NoCoffee (Firefox)
A very simple open-source tool that can be helpful for choosing contrasting colours is Color 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 colourblindness or in greyscale.
Normal MediaWiki list markup is unfortunately incompatible with normal MediaWiki paragraph markup. To put multiple paragraphs in a list item, Y separate them with {{pb}}:
* This is one item.{{pb}}This is another paragraph within this item.
* This is another item.
Do not N 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.
Definitely do not N 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.
Alternatively, you can Y use one of the HTML list templates to 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.
}}
An accessible approach to indentation is the template {{block indent}} for multi-line content; it uses CSS to 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 abuse the <blockquote>...</blockquote> element or templates that use it (such as {{Quote}}) for visual indentation; they are only for directly quoted material.
A colon (:) at the start of a line marks that line in the MediaWiki parser as the <dd>...</dd> part of an HTML description list (<dl>...</dl>).[a] 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 fails validation[5]). 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, or reuse, but is currently commonly used, despite the problems it causes for users of screen readers.
Blank lines must not be 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 a blank line is needed, place the same number of colons on it as those preceding the text below the blank line, for instance:
: Text here.
:
: More text.
Another solution is new-paragraph markup, but it must be in one unbroken line in the wiki code:
Improper use of a semicolon to bold a "fake heading" before a list (figure 1) creates a list 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).
请避免使用表格做纯排版用途。Data tables provide extra information and navigation methods that can be confusing when the content lacks logical row and column relationships. 最佳的选择是使用更有适应性的HTML的<div>块和样式(style)属性。
When using a table to position non-tabular content, help screen readers identify it as a layout table, not a data table. Set a role="presentation" attribute on the table, and do not set any summary attribute. 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" class="toccolors" style="width:94%"
| colspan="2" style="text-align: center; background-color: #ccf;" | <strong>Important text</strong>
|-
| The quick || brown fox
|-
| jumps over || the lazy dog.
|}
Avoid indiscriminate gallery sections because screen size and browser formatting may affect accessibility for some readers due to fragmented image display.
In addition, animations Template:Strong-em produce more than three flashes in any one-second period. Content that flashes more than that limit is known to cause seizures.[12]
一般來講,文章應優先於使用Wiki標記來替代HTML元素。尤其是,不要使用物理HTML標籤<i>...</i>和<b>...</b>來單純格式粗體、斜體文字,請使用Wiki標記'''、'',或是語意HTML(Semantic HTML)(英语:Semantic_HTML)。<font>標籤也應該要盡量避免在文章中使用;使用邏輯模板(例如{{em}}、{{strong}}或{{code}})來強調與其它文字的不同之處。使用及{{small}}及{{big}}模板來改變文字大小,而非以font-size=方式或是已過時的<small>來設定樣式。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 generally not used in article text.
Auto-collapsed (pre-collapsed) elements should not be used to hide content in the article's main body, though elements such as tables can be made collapsible at the reader's option.
^HTML description lists were formerly called definition lists and association lists. The <dl><dt>...</dt><dd>...</dd></dl> structure is the same; only the terminology has changed between HTML specification versions.