F Kitchen Sink

Accessibility audit rules

Document language

Accessibility rule handbook metadata

Rule
DET.A11Y.GENERIC.LANG · lane deterministic · scope generic
Page status
current
page_version
60f571c82ca663702dd2ee5b21455a0a1823ed29853fe146ca8c33ad4bbb1b9c
generated_at
2026-05-26T08:51:23.000Z
registry_fingerprint
e11a2939d018a45bae7d6e23364aba2ae4e13f190d942f49891c89ea84c44c46

How this rule is checked

Deterministic lane — scope generic. Detected by det-a11y-generic-*.check.js or the axe lane for WCAG-tagged violations.

  • Harness: auditor-tests/invoke-a11y-ruleset-harness.sh on the Before fixture.
  • Audit: analyze-website-a11y.mjs --only-deterministic-rule-ids DET.A11Y.GENERIC.LANG

Module: docs/design/a11y-audit/deterministic-a11y-rules.md#det-a11y-generic-lang. See Before / After below.

Purpose

Root html must declare lang.

Passing signals

  • DOM and/or repo signals satisfy the rule implementation in tools/website-a11y-auditor.
  • For axe-backed WCAG criteria, use --lanes axe,det with an appropriate --standard preset.

Failing signals

  • Auditor emits a finding with ruleId DET.A11Y.GENERIC.LANG on the crawled URL.
  • Harness: auditor-tests/invoke-a11y-ruleset-harness.sh DET.A11Y.GENERIC.LANG expects ≥1 finding on the Before fixture.

Before example

Before (failing example)

Page without lang

Simulates missing html[lang].

After example

After (passing example)

Page with lang

Assistive tech can pick en-US voice.

Evidence and remediation

  1. Reproduce with analyze-website-a11y.mjs --only-deterministic-rule-ids DET.A11Y.GENERIC.LANG when lane is deterministic.
  2. Apply the After markup pattern (or fix generator source for KS rules).
  3. Re-run harness or audit until the rule is clean on the target URL.