A11y Check

KWCAG 2.2 · 8.1.1

How to test Parsing / valid markup

How to evaluate the KWCAG 2.2 checkpoint “Parsing / valid markup”. Automation can decide this checkpoint on its own.

Which standards this maps to

Korean standard (KWCAG 2.2)
8.1.1 Parsing / valid markup
Robust
International standard (WCAG 2.2)
4.1.1

How to test it

Automated checks re-parse the source HTML with a standards parser to detect unclosed elements, mis-nesting, duplicate attributes, and duplicate ids, plus ARIA-referenced id duplicates in the rendered DOM. Limitation: nesting the parser recovers silently (e.g., div inside p) is not detected — use the W3C Nu HTML Checker for full syntax when needed.

What automation covers

4 automated rules judge this checkpoint. Each comes with remediation guidance.

  • IDs of active elements must be unique duplicate-id-active

    Ensure every id in the document is unique.

  • IDs used in ARIA must be unique duplicate-id-aria

    IDs referenced by ARIA attributes must be unique.

  • Markup has structural errors a11ychk:markup-validity

    The source HTML contains structural errors (unclosed or mis-nested elements, duplicate attributes, self-closing non-void tags). Browsers recover silently but recovery differs across browsers and assistive tech. Locations are given as line:col in the source.

  • Duplicate ids in the document a11ychk:duplicate-id

    Every id must be unique within the document. Duplicates break label associations, ARIA references, anchors, and scripts. Unlike axe's duplicate-id rules (active/ARIA-referenced ids only), this check inspects every id in the source.

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