WCAG 2.1 Proposed Recommendation (勧告案)

W3C が勧告している WCAG (Web Content Accessibility Guidelines) 2.0 の次期バージョンである WCAG 2.1 が、Proposed Recommendation (勧告案) として2018年4月28日に開示されました。最終的な勧告 (2018年6月予定) まで「あと一歩」というステータスで、言わば最終確認の状態と言えます。

この勧告案のひとつ前の段階として、先に「WCAG 2.1 Candidate Recommendation (勧告候補)」という記事を書きましたが、そこで挙がっていた達成基準は概ね変更なく勧告案に盛り込まれています。勧告候補の時点で「at risk」というタグが付けられた達成基準もありましたが、いずれも勧告案では「落選」せず残っており、実効性の確証が得られたようです。

この記事では、今回の勧告案で見られる WCAG 2.1 の新達成基準を一覧としてまとめてみましたので、共有したいと思います。

ガイドライン 1.3 Adaptable (適応可能)

# 達成基準 レベル 詳細 フォーカス 備考
1.3.4 Orientation AA Content does not restrict its view and operation to a single display orientation, such as portrait or landscape, unless a specific display orientation is essential. モバイル 達成基準 2.6.2 から移動。文面は勧告候補から変更なし。
1.3.5 Identify Input Purpose AA The purpose of each input field collecting information about the user can be programmatically determined when: 認知/学習 達成基準番号変更 (1.3.4→1.3.5)。達成基準ラベルが「Identify Common Purpose」から変更。本文の文面変更あり。
1.3.6 Identify Purpose AAA In content implemented using markup languages, the purpose of User Interface Components, icons, and regions can be programmatically determined. 認知/学習 達成基準番号変更 (1.3.5→1.3.6)。文面は勧告候補から変更なし。

ガイドライン 1.4 Distinguishable (判別可能)

# 達成基準 レベル 詳細 フォーカス 備考
1.4.10 Reflow AA Content can be presented without loss of information or functionality, and without requiring scrolling in two dimensions for:
  • Vertical scrolling content at a width equivalent to 320 CSS pixels;
  • Horizontal scrolling content at a height equivalent to 256 CSS pixels;
Except for parts of the content which require two-dimensional layout for usage or meaning.
ロービジョン 勧告候補から変更なし。
1.4.11 Non-text Contrast AA The visual presentation of the following have a contrast ratio of at least 3:1 against adjacent color(s):
User Interface Components:
Visual information used to indicate states and boundaries of user interface components, except for inactive components or where the appearance of the component is determined by the user agent and not modified by the author;
Graphical Objects:
Parts of graphics required to understand the content, except when a particular presentation of graphics is essential to the information being conveyed.
ロービジョン 勧告候補から変更なし。
1.4.12 Text Spacing AA In content implemented using markup languages that support the following text style properties, no loss of content or functionality occurs by setting all of the following and by changing no other style property:
  • Line height (line spacing) to at least 1.5 times the font size;
  • Spacing following paragraphs to at least 2 times the font size;
  • Letter spacing (tracking) to at least 0.12 times the font size;
  • Word spacing to at least 0.16 times the font size.
Exception: Human languages and scripts that do not make use of one or more of these text style properties in written text can conform using only the properties that exist for that combination of language and script.
ロービジョン 文面変更あり。
1.4.13 Content on Hover or Focus AA Where receiving and then removing pointer hover or keyboard focus triggers additional content to become visible and then hidden, the following are true:
A mechanism is available to dismiss the additional content without moving pointer hover or keyboard focus, unless the additional content communicates an input error or does not obscure or replace other content;
If pointer hover can trigger the additional content, then the pointer can be moved over the additional content without the additional content disappearing;
The additional content remains visible until the hover or focus trigger is removed, the user dismisses it, or its information is no longer valid.
Exception: The visual presentation of the additional content is controlled by the user agent and is not modified by the author.
ロービジョン 文面変更あり。

ガイドライン 2.1 Keyboard Accessible (キーボード操作可能)

# 達成基準 レベル 詳細 フォーカス 備考
2.1.4 Character Key Shortcuts A If a keyboard shortcut is implemented in content using only letter (including upper- and lower-case letters), punctuation, number, or symbol characters, then at least one of the following is true:
Turn off:
A mechanism is available to turn the shortcut off;
A mechanism is available to remap the shortcut to use one or more non-printable keyboard characters (e.g. Ctrl, Alt, etc).
Active only on focus:
The keyboard shortcut for a user interface component is only active when that component has focus.
モバイル 達成基準 2.4.11 から移動。文面は勧告候補から変更なし。

ガイドライン 2.2 Enough Time (十分な時間)

# 達成基準 レベル 詳細 フォーカス 備考
2.2.6 Timeouts AAA Users are warned of the duration of any user inactivity that could cause data loss, unless the data is preserved for more than 20 hours when the user does not take any actions. 認知/学習 勧告候補から変更なし。

ガイドライン 2.3 Seizures and Physical Reaction (発作および身体反応の防止)

今回の勧告案で、ガイドライン 2.3 のラベルが「Seizures (発作の防止)」から「Seizures and Physical Reaction」に変更されています。なお、上記和訳 (発作および身体反応の防止) は私案です。
# 達成基準 レベル 詳細 フォーカス 備考
2.3.3 Animation from Interactions AAA Motion animation triggered by interaction can be disabled, unless the animation is essential to the functionality or the information being conveyed. 認知/学習 達成基準 2.2.7 から移動。文面は勧告候補から変更なし。

[新規] ガイドライン 2.5 Input Modalities (入力モダリティ)

今回の勧告案で、ガイドライン 2.5 のラベルが「Pointer Accessible」から「Input Modalities」に変更されています。なお、上記和訳 (入力モダリティ) は私案です。
# 達成基準 レベル 詳細 フォーカス 備考
2.5.1 Pointer Gestures A All functionality that uses multipoint or path-based gestures for operation can be operated with a single pointer without a path-based gesture, unless a multipoint or path-based gesture is essential. モバイル 勧告候補から変更なし。
2.5.2 Pointer Cancellation A For functionality that can be operated using a single pointer, at least one of the following is true:
No Down-Event:
The down-event of the pointer is not used to execute any part of the function;
Abort or Undo:
Completion of the function is on the up-event, and a mechanism is available to abort the function before completion or to undo the function after completion;
Up Reversal:
The up-event reverses any outcome of the preceding down-event;
Completing the function on the down-event is essential.
モバイル 文面変更あり。
2.5.3 Label in Name A For user interface components with labels that include text or images of text, the name contains the text presented visually. モバイル 達成基準 2.4.12 から移動。文面変更あり。
2.5.4 Motion Actuation A Functionality that can be operated by device motion or user motion can also be operated by user interface components and responding to the motion can be disabled to prevent accidental actuation, except when:
Supported Interface:
The motion is used to operate functionality through an accessibility supported interface;
The motion is essential for the function and doing so would invalidate the activity.
モバイル 達成基準 2.6.1 から移動。文面は勧告候補から変更なし。
2.5.5 Target Size AAA The size of the target for pointer inputs is at least 44 by 44 CSS pixels except when:
The target is available through an equivalent link or control on the same page that is at least 44 by 44 CSS pixels;
The target is in a sentence or block of text;
User Agent Control:
The size of the target is determined by the user agent and is not modified by the author;
A particular presentation of the target is essential to the information being conveyed.
モバイル 達成基準番号変更 (2.5.3 → 2.5.5)。文面は勧告候補から変更なし。
2.5.6 Concurrent Input Mechanisms AAA Web content does not restrict use of input modalities available on a platform except where the restriction is essential, required to ensure the security of the content, or required to respect user settings. モバイル 達成基準番号変更 (2.5.4 → 2.5.6)。文面は勧告候補から変更なし。

ガイドライン 4.1 Compatible (互換性)

# 達成基準 レベル 詳細 フォーカス 備考
4.1.3 Status Messages AA In content implemented using markup languages, status messages can be programmatically determined through role or properties such that they can be presented to the user by assistive technologies without receiving focus. 認知/学習 達成基準 3.2.6 から移動。ラベルが「Status Changes」から変更。本文の文面変更なし。