相关标准

WCAG2.0指南

2008 年 12 月 11 日 W3C 推荐标准

WCAG 2.0 指南

1 可感知的
1.1 为所有非文本内容提供文本替代方案，使其可以转化 　　为用户需要的其他格式，比如，大字排版、盲文、语音、符号或者更简单的语言。
1.2 为基于时间的媒体提供替代方案。
1.3 在不丢失信息和结构的情况下，创建的内容可以在不通的方式中展现。例如：更简单的布局。
1.4 使用户更容易看到和听到内容，包括区分前景色和背景色。

2 可操作的

2.1 让所有功能都能有效的通过键盘操作。
2.2 要提供给用户足够的时间去阅读和使用内容。
2.3 不要设计已知的可以导致癫痫发作的内容。

2.4 提供可以帮助用户导航、查找内容以及确定当前所在位置的方法。

3 可理解的

3.1 让文字内容可读并且可理解。
3.2 让网页在可预见的方式中呈现和交互。
3.3 帮助用户避免和纠正错误。
4 健壮性
4.1 最大程度的兼容当前和未来的用户代理，包括辅助技术。

WCAG2.0 指南

本节为规范内容。

1.1.1 Non-text Content: All non-text content that is presented to the user has a text alternative that serves the equivalent purpose, except for the situations listed below. (Level A)
1.1.1非文本内容：所有展示给用户的非文本内容都要有一个提供等价目的的文本替代方案。除了下面列出的情况：（A 级）
Controls, Input: If non-text content is a control or accepts user input, then it has a name that describes its purpose. (Refer to Guideline 4.1 for additional requirements for controls and content that accepts user input.)
控件、输入：如果非文本内容是一个控件或者可接受用户的输入，那么它需要有一个名字来描述它的目的。（对可接受用户输入的控件和内容的额外要求可参看指南 4.1）
Time-Based Media: If non-text content is time-based media, then text alternatives at least provide descriptive identification of the non-text content. (Refer to Guideline 1.2 for additional requirements for media.)
基于时间的媒体：如果非文本内容是基于时间的媒体，那么文本替代方案至少要提供描述性信息来标识非文本内容。
Test: If non-text content is a test or exercise that would be invalid if presented in text, then text alternatives at least provide descriptive identification of the non-text content.
测试：如果非文本内容是一个测试或者习题，以文本形式展示就会失效，那么文本替代方案至少要提供描述性的信息来标识非文本内容。
Sensory: If non-text content is primarily intended to create a specific sensory experience, then text alternatives at least provide descriptive identification of the non-text content.
感官：如果非文本内容主要是为了创建一个具体的感官体验，那么文本替代方案至少要提供描述性的信息来标识非文本内容。
CAPTCHA: If the purpose of non-text content is to  that content is being accessed by a person rather than a computer, then text alternatives that identify and describe the purpose of the non-text content are provided, and alternative forms of CAPTCHA using output modes for different types of sensory perception are provided to accommodate different disabilities.
验证码：如果非文本的内容是用来确定是用户而不是电脑在访问内容，那么应提供用来识别和描述非本文内容的文本替代方案并
且提供不同类型感官可感知的输出方案，作为验证码的替代方式来适应不同的残障。
Decoration, Formatting, Invisible: If non-text content is pure decoration, is used only for visual formatting, or is not presented to users, then it is implemented in a way that it can be ignored by assistive technology.
装饰、格式、不可见：如果非文本内容是纯粹的装饰或者仅仅用于视觉格式又或者对用户不可见，那么它采用一种使辅助技术可
以忽略它的实现方式。

1.2.1 Audio-only and Video-only (Prerecorded): For prerecorded audio-only and prerecorded video-only media, the following are true, except when the audio or video is a media alternative for text and is clearly labeled as such: (Level A)
1.2.1纯视频和纯音频（预先录制的）：对于预先录制好的纯音频和纯视频，要遵循下面要求，除非视频或音频是文字的媒体替代方案并且清晰地标明。（A 级）
Prerecorded Audio-only: An alternative for time-based media is provided that presents equivalent information for prerecorded audio-only content.
预先录制好的纯音频：为预先录制好的纯音频内容提供一个用于展示等价信息的基于时间的媒体替代方案。
Prerecorded Video-only: Either an alternative for time-based media or an audio track is provided that presents equivalent information for prerecorded video-only content.
预先录制好的纯视频：为预先录制好的纯音频内容提供一个用于展示等价信息的的基于时间的媒体或者音轨的替代方案。
1.2.2Captions (Prerecorded): Captions are provided for all prerecorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labeled as such. (Level A)
1.2.2字幕（预先录制好的）：为同步媒体中所有预先录制好的音频提供字幕，除非媒体是文字的媒体替代方案并且清晰地标明。（A 级）
1.2.3Audio Description or Media Alternative (Prerecorded): An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media, except when the media is a media alternative for text and is clearly labeled as such. (Level A)
1.2.3音频描述或者媒体代替方案（预先录制好的）：为同步媒体提供基于时间的媒体替代方案或者预先录制的视频的音频描述，除非媒体是文字的媒体替代方案并且清晰的表明。（A 级）
1.2.4Captions (Live): Captions are provided for all live audio content in synchronized media. (Level AA)
1.2.4字幕（直播）：为同步媒体中的所有直播的音频内容提供字幕。（AA 级）
1.2.5Audio Description (Prerecorded): Audio description is provided for all prerecorded video content in synchronized media. (Level AA)
1.2.5音频描述（预先录制好的）：为同步媒体中的左右预先录制的视频提供音频描述。（AA 级）
1.2.6Sign Language (Prerecorded): Sign language interpretation is provided for all prerecorded audio content in synchronized media. (Level AAA)
1.2.6手语（预先录制好的）：为同步媒体中的所有预先录制好的音频内容提供手语解释。（AAA 级）
1.2.7Extended Audio Description (Prerecorded): Where pauses in foreground audio are insufficient to allow audio descriptions to convey the sense of the video, extended audio description is provided for all prerecorded video content in synchronized media. (Level AAA)
1.2.7扩展的音频描述（预先录制好的）：当前景音暂停，音频描述不足以传达视频的意义时，要为同步媒体中所有预先录制好的音频内容提供扩展的音频描述。（AAA 级）
1.2.8Media Alternative (Prerecorded): An alternative for time- based media is provided for all prerecorded synchronized media and for all prerecorded video-only media. (Level AAA)
1.2.8媒体替代方案（预先录制好的）：为所有预先录制好的同步媒体和预先录制好的纯视频媒体提供基于时间的媒体替代方案。（AAA 级）
1.2.9Audio-only (Live): An alternative for time-based media that presents equivalent information for live audio-only content is provided. (Level AAA)
1.2.9 纯音频（直播）：为直播的纯音频内容提供用于展示等价信息的基于时间的媒体替代方案。（AAA 级）

1.3.1 Info and Relationships: Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text. (Level A)
1.3.1信息和关系：表现所传递出的信息、结构、关系可以通过编程方式决定或者以有效的文本形式存在。（A 级）
1.3.2Meaningful Sequence: When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically determined. (Level A)
1.3.2顺序是有意义的：当内容的顺序可以影响它本身的含义，可以利用程序来确定一个正确的阅读顺序（A 级）
1.3.3Sensory Characteristics: Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, size, visual location, orientation, or sound. (Level A)
1.3.3 感官特征：为理解和操作内容提供的说明不应该仅仅依赖于组件的感官特征，比如：形状、大小、视觉位置、方向或者声音。（A 级）
Note: For requirements related to color, refer to Guideline 1.4.
注：颜色相关的要求，参看：指南 1.4

1.4.1Use of Color: Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. (Level A)
颜色的使用：颜色不应做为传递信息、指示操作、提示响应或者区别
可视元素的唯一方法。（A 级）
Note: This success criterion addresses color perception specifically. Other forms of perception are covered in Guideline 1.3 including programmatic access to color and other visual presentation coding.
提示：这个成功标准专门解决颜色的感知。指南 1.3 涵盖了其他感知形式，包括以编程的方式获取颜色和其他视觉表现的代码。
1.4.2Audio Control: If any audio on a Web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume independently from the overall system volume level. (Level A)
1.4.2音频控制：如果一个网页上任何自动播放的音频超过 3 秒，就需要一个暂停或者停止的有效机制，或者一个独立于所有系统声音级别的控制音频声音有效机制。（A 级）
Note: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether or not it is used to meet other success criteria) must meet this success criterion. See Conformance Requirement 5: Non-Interference.
提示：由于任何未能满足此成功标准的内容都会干扰用户使用整个网页，所以网页上的所有内容（无论它是否满足其他的成功标准）都必须实现这个成功标准。参看：一致性要求 5：互不干涉。
1.4.3Contrast (Minimum): The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following: (Level AA)
1.4.3对比度（最小值）：除了下面几点，文本和图片式文本的视觉感知的对比度比至少为 4.5:1：（AA 级）
Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 3:1;大号文本：可放大的文本和图片式的可放大文本的对比度比至少为 3:1；
Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.
附属的：文本或者图片式的文本是未激活的用户组件的一部分、纯装饰性、对任何人不可见，或者一个包含有意义的视觉内容的
图片的一部分，没有对比度要求。
Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.
Logo 类型：文字是 logo 或者是品牌名字的一部分可以没有最小对比度的要求。
1.4.4Resize text: Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality. (Level AA)
1.4.4调整文本：除了字幕和图片式文本，在不使用辅助技术的情况下文本可以放大到 200%并且没有内容和功能的损失。
1.4.5Images of Text: If the technologies being used can achieve the visual presentation, text is used to convey information rather than images of text except for the following: (Level AA)
1.4.5图片式文字：如果视觉感知方式能用技术能实现，除了下列情况， 使用文本传递信息要比图片式文字好：（AA 级）
Customizable: The image of text can be visually customized to the user's requirements;
可定制的：可以根据用户需要的视觉定制的图片式文本。
Essential: A particular presentation of text is essential to the information being conveyed.
必不可少的：文字是一个必不可少的传递信息的具体感知方式。
Note: Logotypes (text that is part of a logo or brand name) are considered essential.
提示：logo 类（logo 或者品牌名称的一部分）必须要考虑。
1.4.6Contrast (Enhanced): The visual presentation of text and images of text has a contrast ratio of at least 7:1, except for the following: (Level AAA)
1.4.6对比度（增强的）：除了下列情况，文本和图片式文本的视觉感知的对比度比最少为 7：1：（AAA 级）
Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 4.5:1;
大号文本：可放大的文本和图片式的可放大文本的对比度比至少为 4.5:1；
Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.
附属的：文本或者图片式的文本是未激活的用户组件的一部分、纯装饰性、对任何人不可见，或者一个包含有意义的视觉内容的图片的一部分，没有对比度要求。
Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.
Logo 类型：文字是 logo 或者是品牌名字的一部分可以没有最小对比度的要求。
1.4.7Low or No Background Audio: For prerecorded audio-only content that (1) contains primarily speech in the foreground, (2) is not an audio CAPTCHA or audio logo, and (3) is not vocalization intended to be primarily musical expression such as singing or rapping, at least one of the following is true: (Level AAA)
1.4.7轻声或者无背景音：对于这几种预先录制好的只有音频的内容，
1）包含主要话语的前景音，2）不是一个音频验证码或者音频 logo，3）没有发声，打算主要音乐用来表达，比如唱歌和说唱，那么要至少要符合下列其中一点：（AAA 级）
No Background: The audio does not contain background sounds.
没有背景音：音频不要包含背景音。
Turn Off: The background sounds can be turned off.
关闭：背景音可以被关闭。
20 dB: The background sounds are at least 20 decibels lower than the foreground speech content, with the exception of occasional sounds that last for only one or two seconds.
20 分贝：背景音至少要比前景话语内容低于 20 分贝，除了偶尔仅仅持续 1~2 秒的声音。
Note: Per the definition of "decibel," background sound that meets this requirement will be approximately four times quieter than the foreground speech content.
注：根据“分贝”的定义，背景音达到这个要求需要比前景话语内容大约安静 4 倍。
1.4.8Visual Presentation: For the visual presentation of blocks of text, a mechanism is available to achieve the following: (Level AAA)
1.4.8视觉感知：对于块状的文本，需要提供一种有效的机制来实现下面的要求：（AAA 级要求）
1.Foreground and background colors can be selected by the user.
用户可以选择前景色和后景色。
2.Width is no more than 80 characters or glyphs (40 if CJK).
宽度不能大于 80 个字符或符号（中、日、韩 40 个字）
3.Text is not justified (aligned to both the left and the right margins).
文本不需要两端对齐（同时将左右两端对齐）
4.Line spacing (leading) is at least space-and-a-half within paragraphs, and paragraph spacing is at least 1.5 times larger than the line spacing.
段落中的行间距至少是 1.5 倍行高，段落间距至少是行间距的1.5 倍。
5.Text can be resized without assistive technology up to 200 percent in a way that does not require the user to scroll horizontally to read a line of text on a full-screen window.
不使用辅助技术，文本可以调整大小到 200%并且在全屏下不需要用户水平滚动去阅读一行文本。
1.4.9Images of Text (No Exception): Images of text are only used for pure decoration or where a particular presentation of text is essential to the information being conveyed. (Level AAA)
1.4.9 图片式文本（没有例外）：图片式文本只用于纯装饰或者文字是一个必不可少的传递信息的具体感知方式。（AAA 级）
Note: Logotypes (text that is part of a logo or brand name) are considered essential.
注：logo 类（logo 或者品牌名称的一部分）必须要考虑。

2.1.1 Keyboard: All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints. (Level A)
2.1.1键盘：内容的所有功能都可以使用键盘接口操作，不对单个按键有具体的时间要求，除非底层功能需要依赖用户的移动路径而不只是路径的终点来输入。（A 级）
Note 1: This exception relates to the underlying function, not the input technique. For example, if using handwriting to enter text, the input technique (handwriting) requires path-dependent input but the underlying function (text input) does not.
注 1：上面描述的例外只适用于与底层功能相关的范畴，而不针对输入技术。举个例子：如果使用手写去输入文字，手写需要依赖路径输入，但是底层的功能（文字输入功能）并不需要依赖路径。
Note 2: This does not forbid and should not discourage providing mouse input or other input methods in addition to keyboard operation.
注 2：这并不是禁止或者阻止提供鼠标或者其他除键盘以外的输入方法。
2.1.2No Keyboard Trap: If keyboard focus can be moved to a component of the page using a keyboard interface, then focus can be moved away from that component using only a keyboard interface, and, if it requires more than unmodified arrow or tab keys or other standard exit methods, the user is advised of the method for moving focus away. (Level A)
2.1.2禁止键盘陷阱：如果焦点通过键盘接口聚焦到到页面上的一个组件上，那么焦点只能使用键盘接口才可以离开这个组件，如果需要除原生箭头键或者 Tab 键以外的其他标准的退出方法，需要将移出焦点的方法传达给用户。（A 级）
Note: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.
注：由于任何未能满足此成功标准的内容都会干扰用户使用整个网页，
所以网页上的所有内容（无论它是否满足其他的成功标准）都必须实现这个成功标准。参看：一致性要求 5：互不干涉。
2.1.3Keyboard (No Exception): All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes. (Level AAA)
2.1.3 键盘（没有例外）：内容的所有功能都可以使用键盘接口操作，不对单个按键有具体的时间要求。（AAA 级）

2.2.1 Timing Adjustable: For each time limit that is set by the content, at least one of the following is true: (Level A)
2.2.1可调整时间：每一个为内容设置的时间限制，至少符合下面其中一点：（A 级）
Turn off: The user is allowed to turn off the time limit before encountering it; or
关闭：在遇到时间限制之前可以允许用户关闭它；或者
Adjust: The user is allowed to adjust the time limit before encountering it over a wide range that is at least ten times the length of the default setting; or
调整：在遇到时间限制之前可以允许用户调整它到一个至少是默认设置 10 倍长度的范围；或者
Extend: The user is warned before time expires and given at least 20 seconds to extend the time limit with a simple action (for example, "press the space bar"), and the user is allowed to extend the time limit at least ten times; or延长：在超时之前要警告用户，并且给出至少 20 秒的时间，让用户可以使用一个简单的操作（例如“按空格键”）来延长时间限
制，同时允许用户延长至少 10 倍的时间；或者
Real-time Exception: The time limit is a required part of a real-time event (for example, an auction), and no alternative to the time limit is possible; or
实时例外：时间限制是实时事件的一个必要部分（例如“一个拍卖”），并且可能没有方案替代时间限制；或者
Essential Exception: The time limit is essential and extending it would invalidate the activity; or
必不可少例外：时间限制是必不可少的并且延长它可能会使活动无效；或者
20 Hour Exception: The time limit is longer than 20 hours.
20 小时例外：时间限制大于 20 小时。
Note: This success criterion helps ensure that users can complete tasks without unexpected changes in content or context that are a result of a time limit. This success criterion should be considered in conjunction with Success Criterion 3.2.1, which puts limits on changes of content or context as a result of user action.
注：这个成功标注会帮助保证用户可以完成任务不会由于时间限制出
现突然的更改内容或者上下文的结果。这个成功标准应该连同成功标准 3.2.1 仔细考虑，让修改内容或上下文的限制作为用户操作的结果。
2.2.2Pause, Stop, Hide: For moving,blinking, scrolling, or auto- updating information, all of the following are true: (Level A)
2.2.2暂停，停止，隐藏：对于移动，闪烁，滚动或者其他自动更新的信息，应该符合一下全部要求：（A 级）
Moving, blinking, scrolling: For any moving, blinking or scrolling information that (1) starts automatically, (2) lasts more than five seconds, and (3) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it unless the movement, blinking, or scrolling is part of an activity where it is essential; and
移动、闪烁、滚动：对于任何符合以下特征的移动，闪烁，滚动的信息，（1）自动开始，（2）持续时间大于 5 秒并且（3）与其他内容同时展示，需要提供个用户一个机制用来暂停、停止或隐藏它，除非移动，闪烁，滚动是一个活动必不可少的一部分。
Auto-updating: For any auto-updating information that (1) starts automatically and (2) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it or to control the frequency of the update unless the auto- updating is part of an activity where it is essential.
自动更新：对于任何符合以下特征的自动更新的信息，（1）自动开始并且（2）与其他内容同时展示，需要提供给用户一个机
制用来暂停、停止或隐藏它或者控制更新频率，除非自动更新是活动必不可少的一部分。
Note 1: For requirements related to flickering or flashing content, refer to Guideline 2.3.
注 1：关于闪烁和闪光的相关要求可参看指南 2.3。
Note 2: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.
注 2：由于任何未能满足此成功标准的内容都会干扰用户使用整个网页，所以网页上的所有内容（无论它是否满足其他的成功标准）都必须实现这个成功标准。参看：一致性要求 5：互不干涉。
Note 3: Content that is updated periodically by software or that is streamed to the user agent is not required to preserve or present information that is generated or received between the initiation of the pause and resuming presentation, as this may not be technically possible, and in many situations could be misleading to do so.
注 3：由软件定期更新的或者传给用户代理不需要请求保存内容，或者在暂停和重新恢复中生成或接收展示的信息，类似这些可能没有技术方案并且在很多情况下可能是误导性的。
Note 4: An animation that occurs as part of a preload phase or similar situation can be considered essential if interaction cannot occur during that phase for all users and if not indicating progress could confuse users or cause them to think that content was frozen or broken.
注 4：以作为预加载阶段的一部分或者类似情形的形式出现的动画必须要考虑如果在这个阶段不与用户发生交互并且没有显示进度可能导致用户困惑或者认为内容冻结或者损坏。
2.2.3No Timing: Timing is not anessential part of the event or activity presented by the content, except for non-interactive synchronized media and real-time events. (Level AAA)
2.2.3不定时：除非是非交互的同步媒体和实时事件，否则定时不应该是展示事件或者活动内容的必不可少的部分。（AAA 级）
2.2.4Interruptions: Interruptions can be postponed or suppressed by the user, except interruptions involving an emergency. (Level AAA)
2.2.4中断：除非中断涉及到一个紧急情况，否则用户可以推迟或者禁止中断。（AAA 级）
2.2.5Re-authenticating: When an authenticated session expires, the user can continue the activity without loss of data after re- authenticating. (Level AAA)
2.2.5 重新验证：当一个验证会话失效，在重新验证之后不 应丢失数据， 用户可以继续进行活动。（AAA 级）

2.3.1 Three Flashes or Below Threshold: Web pages do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds. (Level A)
2.3.1三次闪烁或者低于阈值：网页中不要包含任何每秒大于三次或者低于普通和红色闪烁阈值的闪烁。（A 级）
Note: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.
注：由于任何未能满足此成功标准的内容都会干扰用户使用整个网页，所以网页上的所有内容（无论它是否满足其他的成功标准）都必须实现这个成功标准。参看：一致性要求 5：互不干涉。
2.3.2Three Flashes: Web pages do not contain anything that flashes more than three times in any one second period. (Level AAA)
2.3.2 三次闪烁：网页中不要包含任何每秒大于三次的闪烁（AAA 级）

2.4.1 Bypass Blocks: A mechanism is available to bypass blocks of content that are repeated on multiple Web pages. (Level A)
2.4.1跳过区域：需要一种机制可以让用户跳过在多个网页上重复的内容区域。
2.4.2Page Titled: Web pages have titles that describe topic or purpose. (Level A)
2.4.2页面标题：网页要有一个描述主题或者用途的标题。（A 级）
2.4.3Focus Order: If a Web page can be navigated sequentially and the navigation sequences affect meaning or operation, focusable components receive focus in an order that preserves meaning and operability. (Level A)
2.4.3焦点序列：如果网页可以按顺序导航并且导航顺序影响含义或者
操作，可聚焦的组件应在一个可以保护含义和可操作性的序列中接收焦点。（A 级）
2.4.4Link Purpose (In Context): The purpose of each link can be determined from the link text alone or from the link text together with its programmatically determined link context, except where the purpose of the link would be ambiguous to users in general. (Level A)
2.4.4链接用途（在上下文中）：仅从链接的文本或者将链接文本和它编程确定的链接上下文关联在一起与就能确定链接的目的，一般来说除非链接的目的是用来迷惑用户。（A 级）
2.4.5Multiple Ways: More than one way is available to locate a Web page within a set of Web pages except where the Web Page is the result of, or a step in, a process. (Level AA)
2.4.5多种方式：在一组网页中有多种方式去有效的定位一个网页，除非网页是一个步骤的结果，或者一个步骤，一个进程。（AA 级）
2.4.6Headings and Labels: Headings and labels describe topic or purpose. (Level AA)
2.4.标题和标签：标题和标签应描述主体或者用途。（AA 级）
2.4.7Focus Visible: Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible. (Level AA)
2.4.7可视的焦点：任何键盘操作的用户界面需要一个键盘焦点的指示是可视的操作模式。（AA 级）
2.4.8Location: Information about the user's location within a set of Web pages is available. (Level AAA)
2.4.8定位：一组网页中关于用户定位的信息应该是有效的。（AAA 级）
2.4.9Link Purpose (Link Only): A mechanism is available to allow the purpose of each link to be identified from link text alone, except where the purpose of the link would be ambiguous to users in general. (Level AAA)
2.4.8 链接用途（仅链接本身）：需要提供一个有效的机制允许仅仅从链接的文本就确定每一个链接的用途，一般来说除非链接的目的就是用来迷惑用户的。（AAA 级）
2.4.10 Section Headings: Section headings are used to organize the content. (Level AAA)
2.4.10 章节标题：使用章节标题来组织内容。（AAA 级）
Note 1: "Heading" is used in its general sense and includes titles and other ways to add a heading to different types of content.
注 1：” heading 标签”用来标识内容的一般语义，包括标题和其他为不
同类型内容添加一个标题的方法。
Note 2: This success criterion covers sections within writing, not user interface components. User Interface components are covered under Success Criterion 4.1.2.
注 2：这个成功标准包含章节中写作的部分，不涵盖用户界面组件。成功标准 4.1.2 涵盖了用户界面组件的信息。

3.1.1 Language of Page: The default human language of each Web page can be programmatically determined. (Level A)
3.1.1页面语言：每个网页默认的人类语言可以由程序来确定。（A 级）
3.1.2Language of Parts: The human language of each passage or phrase in the content can be programmatically determined except for proper names, technical terms, words of indeterminate language, andwords or phrases that have become part of the vernacular of the immediately surrounding text. (Level AA)
3.1.2网页中各个部分的语言：内容里的每一段或者每一个短语的人类语言都可以由程序来确定。除了专有名称、技术术语、无法确定语言的词语以及部分紧邻文本周围的方言。（AA 级）
3.1.3Unusual Words: A mechanism is available for identifying specific definitions of words or phrases used in an unusual or restricted way, including idioms and jargon. (Level AAA)
3.1.3非常用词汇：需要有一种有效的机制，来识别非常用或限制级的词语或词组的具体含义，包括成语和难懂的术语。（AAA 级）
3.1.4Abbreviations: A mechanism for identifying the expanded form or meaning of abbreviations is available. (Level AAA)
3.1.4缩写：需要有一种有效机制，来识别缩写的全称或含义。（AAA 级）
3.1.5Reading Level: When text requires reading ability more advanced than the lower secondary education level after removal of proper names and titles, supplemental content, or a version that does not require reading ability more advanced than the lower secondary education level, is available. (Level AAA)
3.1.5阅读级别： 当删除专有名称、标题和补充内容之后的文本还需要高于初中教育水平阅读能力的时候，就要有一个不需要阅读能力高于初中教育水平的版本。（AAA 级）
3.1.6Pronunciation: A mechanism is available for identifying specific pronunciation of words where meaning of the words, in context, is ambiguous without knowing the pronunciation. (Level AAA)
3.1.6 发音：当词语在上下文中不知道其发音就会引起歧义时，需要一个机制来识别词语的具体发音。（AAA 级）

3.2.1 On Focus: When any component receives focus, it does not initiate a change of context. (Level A)
3.2.1聚焦：任何组件当它接收焦点的时候，不能导致上下文的变化。（A 级）
3.2.2On Input: Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component. (Level A)
3.2.2输入：除非用户在使用组件之前被告知，否则任何改变用户界面的设置都不应该自动导致上下文的变化。（A 级）
3.2.3Consistent Navigation: Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user. (Level AA)
3.2.3一致的导航：除非用户改变导航机制，否则在一组网页中，多个网页重复出现的时候，他们的相对位置都应该是相同的。（AA 级）
3.2.4Consistent Identification: Components that have the same functionality within a set of Web pages are identified consistently. (Level AA)
3.2.4一致的识别性：在一组网页中相同功能的组件的识别性要一致。（AA 级）
3.2.5Change on Request: Changes of context are initiated only by user request or a mechanism is available to turn off such changes. (Level AAA)
3.2.5 应要求改变：只有用户的要求才能导致上下文的改变，或者提供一种关闭上下文改变的有效机制。（AAA 级）

3.3.1 Error Identification: If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text. (Level A)
3.3.1错误识别：如果一个输入错误是可以自动检测的，那么这个项目的错误应被用户发现，并且用文字进行表述。（A 级）
3.3.2Labels or Instructions: Labels or instructions are provided when content requires user input. (Level A)
3.3.2标签或操作说明：当内容需要用户输入的时候，需要提供标签或者操作说明。（A 级）
3.3.3Error Suggestion: If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content. (Level AA)
3.3.3错误提示：如果可以自动检测输入错误并且提供已知的修改建议， 那么除非提示会危害到内容的安全和目的，否则应该将它提供给用户。（AA 级）
3.3.4Error Prevention (Legal, Financial, Data): For Web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true: (Level AA)
3.3.4错误预防（法律、金融、数据）：对于用户操作可以引起法律承诺或者金融交易的网页，修改或者删除数据存储系统里用户可操作的数据，或者提交用户验证的响应，至少要遵循以下其中一点：（AA 级）
1.Reversible: Submissions are reversible.
可逆的：提交是可逆的。
2.Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.
检查：检查用户输入的数据是否有输入错误并且给用户提供一个修改他们的机会。
3.Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.
确认：在最后提交之前，需要提供一个检查、确认和修改信息的有效机制。
3.3.5Help: Context-sensitive help is available. (Level AAA)
3.3.5帮助：提供上下文相关帮助。（AAA 级别）
3.3.6Error Prevention (All): For Web pages that require the user to submit information, at least one of the following is true: (Level AAA)
3.3.6错误预防（所有）：对于需要用户提交的信息的网页，至少要遵循以下其中一点：（AAA 级）
1.Reversible: Submissions are reversible.
可逆的：提交是可逆的。
2.Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.
检查：检查用户输入的数据是否有输入错误并且给用户提供一个修改他们的机会。
3.Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.
确认：在最后提交之前，需要提供一个检查、确认和修改信息的有效机制。

4.1.1 Parsing: In content implemented using markup languages, elements have complete start and end tags, elements are nested according to their specifications, elements do not contain duplicate attributes, and any IDs are unique, except where the specifications allow these features. (Level A)
4.1.1语法解析：使用标记语言来组织内容，元素要有完整的开始和结束标签，要根据他们的规范来嵌套，不能包含重复的属性，除非规范允许，否则任何 ID 都是唯一的。（A 级）
Note: Start and end tags that are missing a critical character in their formation, such as a closing angle bracket or a mismatched attribute value quotation mark are not complete.
注：在开始和结束的标签组成中缺少关键字符，比如：一个右尖括号、属性值不匹配或者双引号不完整。
4.1.2Name, Role, Value: For all user interface components (including but not limited to: form elements, links and components generated by scripts), the name and role can be programmatically determined; states, properties, and values that can be set by the user can be programmatically set; and notification of changes to these items is available to user agents, including assistive technologies. (Level A)
4.1.2 名称、角色、值：对于所有的用户界面组件（包括但不限于：表单元素、链接以及由脚本生成的组件），他们的名称和角色可以通过编程确定；状态、属性和值可以通过编程来设置；这些项目变化的通知对包括辅助技术在内的用户代理应该是可用的。（A 级别）
Note: This success criterion is primarily for Web authors who develop or  their own user interface components. For example, standard HTML controls already meet this success criterion when used according to specification.
注：这个成功标准主要是用于自己开发或者编写用户界面组件脚本的
作者。举个例子：当根据标准使用 HTML 控件的时候就已经达到了成功的标准。

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