Markup Validity
Topic | Technique | WCAG AA Requirement |
---|---|---|
Unique Identifiers | Unique IDs: IDs MUST be unique within a web page. | Required WCAG 4.1.1 |
Unique Names: The "accessible names" of elements, when provided, of block level elements (e.g. landmarks, tables, iframes, etc.) SHOULD be unique within a web page. Note: The accessible name is determined by attributes or elements such as |
best practice | |
One Attribute Instance: Elements MUST NOT contain more than one instance of the same attribute. | Required WCAG 4.1.1 |
|
Well Formed | Closing Tags: Elements must not be missing closing tags. DIV or P element must not be nested within a LABEL element. Element must not contain duplicate attributes. |
Required WCAG 4.1.1 |
Nesting and Relationships | Parent-Child Relationships: Markup MUST adhere to required parent-child relationships of elements and attributes. | Required WCAG 4.1.1 |
ARIA relationships: ARIA relationships (e.g. parent-child, aria-owns, etc.) SHOULD adhere to WAI-ARIA Authoring Practices | Required WCAG 4.1.1 |
|
Deprecated Markup | Deprecated Markup should not be used. | best practice |