ARIA dialog and alertdialog nodes should have an accessible name

Ensures the complementary landmark or aside is at top level.

Complementary content is content that supports the primary idea of a page or document. Users of screen readers have the option to bypass supplemental content that shows at the accessibility API’s top level. Embedding an <aside> element within another landmark may prevent the ability for screen reader users to browse through supplemental content.

What this Accessibility Rule Checks

Do not insert <aside> elements or elements containing role="complementary" inside landmark-marked content.

To enable screen reader users to navigate the heading structure with keyboard shortcuts rather than wasting time listening to more of the website to understand its structure, make sure the page, or at least one of its frames, contains a h1 element that appears before the start of the main content.

Users of screen readers can utilize keyboard keys to move straight to the first h1, which should, in theory, let them access the web page’s main content. Screen reader users must listen to more of the website in order to understand its structure if there is no h1 or if it appears elsewhere other than at the start of the main material, wasting significant time.

Keep in mind that unlike a visual user, a blind user cannot just glance at a web page and comprehend its layout. Without reading the entire material, visual users can learn a lot about the website layout. Users who are blind do not have such option. Unless there is another convenient way to gain a “glimpse,” screen readers read sequentially, which requires listening to the entire web page. It turns out that one method to do that is to use headers. Keyboard shortcuts can be used by screen reader users to move around a document’s heading hierarchy.

What this Accessibility Rule Checks

This rule locates every element that matches the subsequent selector and confirms that there is at least one of them: h1:not([role]), [role="heading"][aria-level="1"]

A document’s accesskey attribute values must all be distinct. Or, to put it another way, accesskeys must not be used more than once to protect keyboard users from unpleasant surprises.

When a document’s accesskey attribute value is supplied, users can quickly activate or switch the focus to a particular element by hitting the designated key (often in tandem with the alt key). The page becomes less accessible as a result of duplicating the values for the accesskey attribute.

Make sure the value of each defined accesskey is distinct and does not interfere with any screen reader or default browser shortcut keys.

Users who must use alternative keyboards or input devices serving as keyboard emulators, users who have problems tracking a pointer, or users who are blind or have low eyesight and cannot employ eye-hand coordination-required devices like mice, cannot operate the content.

What this Accessibility Rule Checks

Makes certain that every element on the page with an accesskey attribute has a different value.

WAI-ARIA role attribute values must be correct. This means that values must be written correctly, correlate to existing ARIA role values, and not be abstract roles in order to properly display the element’s purpose.

When an assigned WAI-ARIA role value for the parent element is invalid, a developer’s intended accessible technology activity is disabled.

When screen readers and other assistive devices do not understand the job of each element on a web page, they cannot interact with it intelligently or explain the role to the user. When the value for a role is invalid, assistive technologies are unable to communicate the element’s features, properties, and methods. Applying role="table" to a <ul>, for example, effectively hijacks the default semantics associated with the <ul> element in a way that screenreaders do not expect, resulting in unexpected behavior.

What this Accessibility Rule Checks

Check all elements with WAI-ARIA role attribute values to confirm the role value is correct. The role value must be appropriate for the element in the context of the document.

The destination, purpose, function, or action of an Aria treeitem element must be made clear in the element’s understandable text for screen reader users.

Users of screen readers are unable to determine the function of items with the role treeitem that lack an accessible name.

What this Accessibility Rule Checks

Ensures that all objects with the role treeitem have a clear, understandable name.