---
title: "Rule reference"
manual: "Accessibility Quality Gate"
version: "main"
permalink: "https://docs.typo3.org/permalink/priebera/typo3-a11y-quality-gate:rule-reference@main"
source: "RuleReference/Index.rst"
rendered: "2026-09-17T16:05:02+00:00"
---

# Rule reference {#rule-reference-1}

AQG ships 48 built-in rules in three categories. Every rule can be enabled
or disabled individually, see [Enabling rules](https://docs.typo3.org/permalink/priebera/typo3-a11y-quality-gate:configuration-rules@main).

The severity column shows the default severity. Some rules adjust their severity
depending on the detected case, for example a missing alternative text versus a
title-only fallback. The WCAG column names the success criteria a rule relates
to. A rule that does not report a finding does not prove conformance with that
criterion.

## Severities {#severities}

-   **Critical**

    A problem that very likely blocks users of assistive technology. Counted
    against [threshold_critical](https://docs.typo3.org/permalink/priebera/typo3-a11y-quality-gate:confval-threshold-critical@main) of the quality gate.

-   **Warning**

    A problem that degrades accessibility or is a likely failure in most
    contexts. Counted against [threshold_warning](https://docs.typo3.org/permalink/priebera/typo3-a11y-quality-gate:confval-threshold-warning@main).

-   **Info**

    A recommendation. Not counted against the quality gate thresholds.

-   **Needs review**

    A case the automated rule cannot decide. A person has to look at it.

## RTE rules {#rte-rules}

Applied to RTE bodytext of `tt_content` during content scans, and used for
the inline highlighting in CKEditor.

| Rule ID | Default severity | WCAG 2.1 / 2.2 reference |
| --- | --- | --- |
| `rte.img_alt_missing` | Critical | 1.1.1 |
| `rte.img_alt_is_filename` | Warning | 1.1.1 |
| `rte.img_alt_too_long` | Warning | 1.1.1 |
| `rte.img_alt_redundant_phrase` | Warning | 1.1.1 |
| `rte.image_in_link_missing_alt` | Critical | 1.1.1, 2.4.4 |
| `rte.svg_missing_title` | Warning | 1.1.1 |
| `rte.empty_heading` | Critical | 1.3.1 |
| `rte.heading_hierarchy_jump` | Warning | 1.3.1 |
| `rte.empty_link` | Critical | 2.4.4 |
| `rte.non_descriptive_link` | Warning | 2.4.4 |
| `rte.link_text_is_url_or_filename` | Warning | 2.4.4 |
| `rte.link_text_duplicate_different_targets` | Warning | 2.4.4 |
| `rte.link_to_document` | Needs review | 2.4.4 |
| `rte.link_to_document_missing_notice` | Info | 2.4.4 |
| `rte.link_new_window_no_warning` | Warning | 3.2.2 |
| `rte.button_label_missing` | Critical | 4.1.2 |
| `rte.form_control_missing_label` | Critical | 4.1.2, 3.3.2 |
| `rte.iframe_missing_title` | Critical | 4.1.2 |
| `rte.table_missing_header` | Warning | 1.3.1 |
| `rte.table_th_missing_scope` | Warning | 1.3.1 |
| `rte.table_missing_caption` | Info | 1.3.1 |
| `rte.duplicate_id` | Warning | 1.3.1 |
| `rte.marquee_or_blink` | Critical | 2.2.2 |

## Structured rules {#structured-rules}

Applied to structured TCA field values during content scans, for example file
reference metadata, content element headers and form field configuration.

| Rule ID | Default severity | WCAG 2.1 / 2.2 reference |
| --- | --- | --- |
| `structured.file_reference_alt` | Critical | 1.1.1 |
| `structured.file_reference_alt_quality` | Warning | 1.1.1 |
| `structured.header_ctype_empty` | Warning | 1.3.1 |
| `structured.header_link_no_text` | Critical | 2.4.4, 4.1.2 |
| `structured.header_level_is_h1` | Needs review | 1.3.1 |
| `structured.uploads_file_missing_description` | Warning | 2.4.4 |
| `structured.table_missing_caption` | Info | 1.3.1 |
| `structured.form_placeholder_as_label` | Warning | 1.3.1, 3.3.2 |
| `structured.form_field_label_missing` | Critical | 1.3.1, 3.3.2 |
| `structured.form_autocomplete_missing` | Warning | 1.3.5 |
| `structured.media_no_transcript_hint` | Needs review | 1.2.1 |

## Rendered HTML rules {#rendered-html-rules}

Applied to the server-rendered HTML of a page. They run for
**Scan this page**, for **Scan site** and for single-page CLI or
Scheduler runs, but not for subtree CLI or Scheduler runs and never in
changed-only mode. See [Rendered page checks](https://docs.typo3.org/permalink/priebera/typo3-a11y-quality-gate:usage-rendered-checks@main) for the full matrix.

| Rule ID | Default severity | WCAG 2.1 / 2.2 reference |
| --- | --- | --- |
| `rendered.img_missing_alt` | Critical | 1.1.1 |
| `rendered.svg_missing_accessible_name` | Warning | 1.1.1 |
| `rendered.empty_heading` | Critical | 1.3.1 |
| `rendered.empty_link` | Critical | 2.4.4 |
| `rendered.empty_button` | Critical | 4.1.2 |
| `rendered.iframe_missing_title` | Critical | 4.1.2 |
| `rendered.form_control_missing_label` | Critical | 4.1.2, 3.3.2 |
| `rendered.duplicate_id` | Warning | 1.3.1 |
| `rendered.table_missing_header` | Warning | 1.3.1 |
| `rendered.table_empty_header` | Warning | 1.3.1 |
| `rendered.html_lang_missing` | Warning | 3.1.1 |
| `rendered.page_title_missing` | Warning | 2.4.2 |
| `rendered.main_landmark_missing` | Needs review | 1.3.1 |
| `rendered.landmark_unique` | Needs review | 1.3.1 |

## Rules of the frontend crawler {#rules-of-the-frontend-crawler}

Frontend scans additionally run axe-core in a real browser. Their findings use
the axe rule identifiers, for example `color-contrast`, `target-size` or
`region`, and are shown on the **Frontend scan** tab. They are not
part of the rule list above and cannot be toggled in the **Rules** tab.

> [!NOTE]
> Rules whose fix is a template or markup change — for example
> `rendered.main_landmark_missing`, `rendered.landmark_unique`,
> `rendered.duplicate_id`, `rendered.html_lang_missing` or
> `color-contrast` — usually cannot be resolved by editors. Route them to
> integrators or developers.