The “heading” role is unnecessary for element “h1” to "h6".

An element like <h1>, <h2>, etc., used to define a heading, does not accept the button role.

The following HTML code is invalid because the <h2> element can’t have role="button"

<h2 role="button">Some heading</h2>

Instead, you can nest the <h2> inside a <div> with that role. In this case however, browsers automatically apply role presentation to all descendant elements of any button element as it is a role that does not support semantic children.

<div role="button">
  <h2>Some heading</h2>
</div>

To fix the W3C HTML Validator issue stating that a heading element like h1, h2, h3, h4, h5 or h6 must not appear as a descendant of the th element, you need to ensure that the HTML structure follows the specifications where a heading element (h1 to h6) is not placed within a table cell element like th.

Here’s an example of what might be causing the issue and how you can correct it:

Incorrect HTML:

<table>
  <tr>
    <th>Month</th>
<!-- Incorrect placement of h1 inside th -->

  </tr>
  <tr>
    <td>January</td>
    <td>$500</td>
  </tr>
</table>

Corrected HTML:

<h1>Revenue per month</h1>
<table>
  <tr>
    <th>Month</th>
    <th>Revenue</th>
  </tr>
  <tr>
    <td>January</td>
    <td>$500</td>
  </tr>
</table>

In the corrected example, the issue is fixed by removing the h1 element from the th element. If you need to style the text inside the th element differently, you can achieve that via CSS without nesting heading elements inside table cell elements.

To fix the W3C HTML Validator issue stating that a heading element like h1, h2, h3, h4, h5 or h6 must not appear as a descendant of the th element, you need to ensure that the HTML structure follows the specifications where a heading element (h1 to h6) is not placed within a table cell element like th.

Here’s an example of what might be causing the issue and how you can correct it:

Incorrect HTML:

<table>
  <tr>
    <th>Month</th>
<!-- Incorrect placement of h2 inside th -->

  </tr>
  <tr>
    <td>January</td>
    <td>$500</td>
  </tr>
</table>

Corrected HTML:

<h2>Revenue per month</h2>
<table>
  <tr>
    <th>Month</th>
    <th>Revenue</th>
  </tr>
  <tr>
    <td>January</td>
    <td>$500</td>
  </tr>
</table>

In the corrected example, the issue is fixed by removing the h2 element from the th element. If you need to style the text inside the th element differently, you can achieve that via CSS without nesting heading elements inside table cell elements.

To fix the W3C HTML Validator issue stating that a heading element like h1, h2, h3, h4, h5 or h6 must not appear as a descendant of the th element, you need to ensure that the HTML structure follows the specifications where a heading element (h1 to h6) is not placed within a table cell element like th.

Here’s an example of what might be causing the issue and how you can correct it:

Incorrect HTML:

<table>
  <tr>
    <th>Month</th>
<!-- Incorrect placement of h3 inside th -->

  </tr>
  <tr>
    <td>January</td>
    <td>$500</td>
  </tr>
</table>

Corrected HTML:

<h4>Revenue per month</h4>
<table>
  <tr>
    <th>Month</th>
    <th>Revenue</th>
  </tr>
  <tr>
    <td>January</td>
    <td>$500</td>
  </tr>
</table>

In the corrected example, the issue is fixed by removing the h3 element from the th element. If you need to style the text inside the th element differently, you can achieve that via CSS without nesting heading elements inside table cell elements.

To fix the W3C HTML Validator issue stating that a heading element like h1, h2, h3, h4, h5 or h6 must not appear as a descendant of the th element, you need to ensure that the HTML structure follows the specifications where a heading element (h1 to h6) is not placed within a table cell element like th.

Here’s an example of what might be causing the issue and how you can correct it:

Incorrect HTML:

<table>
  <tr>
    <th>Month</th>
<!-- Incorrect placement of h4 inside th -->

  </tr>
  <tr>
    <td>January</td>
    <td>$500</td>
  </tr>
</table>

Corrected HTML:

<h4>Revenue per month</h4>
<table>
  <tr>
    <th>Month</th>
    <th>Revenue</th>
  </tr>
  <tr>
    <td>January</td>
    <td>$500</td>
  </tr>
</table>

In the corrected example, the issue is fixed by removing the h4 element from the th element. If you need to style the text inside the th element differently, you can achieve that via CSS without nesting heading elements inside table cell elements.