rgaa-tables

name	rgaa-tables
description	Audit a web page for RGAA v4.1.2 Theme 5 – Tables accessibility compliance. Checks that complex data tables have summaries, layout tables linearize correctly, data tables have proper titles and headers, and header-cell associations are correct. Use this skill when someone asks to check table accessibility, verify RGAA Theme 5, audit data tables, or check table markup on a website.

RGAA Tables Accessibility Audit (Theme 5)

Audits a web page against the 8 criteria of RGAA v4.1.2 Theme 5: Tables.

Audit procedure

Step 1: Gather table data

(() => {
  const tables = [];
  document.querySelectorAll('table').forEach((table, i) => {
    const ths = Array.from(table.querySelectorAll('th')).map(th => ({
      text: th.textContent.trim().substring(0, 50),
      scope: th.getAttribute('scope'),
      id: th.getAttribute('id'),
      headers: th.getAttribute('headers')
    }));
    const tds = Array.from(table.querySelectorAll('td')).map(td => ({
      headers: td.getAttribute('headers'),
      hasContent: !!td.textContent.trim()
    }));
    const caption = table.querySelector('caption');

    tables.push({
      index: i,
      role: table.getAttribute('role'),
      ariaLabel: table.getAttribute('aria-label'),
      ariaLabelledby: table.getAttribute('aria-labelledby'),
      ariaDescribedby: table.getAttribute('aria-describedby'),
      summary: table.getAttribute('summary'),
      hasCaption: !!caption,
      captionText: caption?.textContent.trim().substring(0, 100),
      rowCount: table.rows.length,
      colCount: table.rows[0]?.cells.length || 0,
      headerCount: ths.length,
      headers: ths.slice(0, 20),
      sampleCells: tds.slice(0, 10),
      isLayoutTable: table.getAttribute('role') === 'presentation' || table.getAttribute('role') === 'none',
      hasTheadTbodyTfoot: !!(table.querySelector('thead') || table.querySelector('tbody') || table.querySelector('tfoot'))
    });
  });
  return JSON.stringify(tables, null, 2);
})()

Step 2: Evaluate criteria

Criterion 5.1 – Complex data tables have a summary. A complex table (multiple header levels, spanning cells) must have a summary explaining its structure, via aria-describedby pointing to a description or a <caption> containing both title and summary.

Criterion 5.2 – Summary of complex data tables is relevant. The summary must help the user understand the table's organization.

Criterion 5.3 – Layout tables linearize correctly. Tables with role="presentation" or role="none" must make sense when read linearly (left to right, top to bottom). They must NOT use <th>, <caption>, <thead>, <tfoot>, <colgroup>, or scope/headers attributes.

Criterion 5.4 – Data table titles are correctly associated. Title must use <caption> directly inside the <table>, or aria-label, or aria-labelledby.

Criterion 5.5 – Data table titles are relevant. Titles must describe the table's content or purpose.

Criterion 5.6 – Column and row headers use <th>. Every header cell must use <th>, not styled <td>.

Criterion 5.7 – Header-cell association uses appropriate technique.

• Simple tables: <th scope="col"> or <th scope="row">
• Complex tables: headers attribute on <td> referencing id values on <th> elements

Criterion 5.8 – Layout tables must not use data table elements. Tables with role="presentation" must not contain: <caption>, <th>, <thead>, <tfoot>, <colgroup>, scope attribute, or headers attribute.

Step 3: Generate report

Classify each table as data table, complex data table, or layout table. Then apply the relevant criteria.