HTML Guide

The “main” element must not appear as a descendant of the “section” element.

main
section

The main element represents the dominant contents of the document, so it should not be contained within another section.

A document must not have more than one main element that does not have the hidden attribute specified.

A hierarchically correct main element is one whose ancestor elements are limited to html, body, div, form without an accessible name, and autonomous custom elements. Each main element must be a hierarchically correct main element.

Learn more:

Related W3C validator issues

A document must not include more than one visible “main” element.

There can only be one visible <main> element in a document. If more are needed (for example for switching between them with JavaScript), only one can be visible, the others should be hidden toggling the hidden attribute.

Example of 2 main elements, where only one is visible:

<main>
  <h1>Active main element</h1>
  <!-- content -->
</main>

<main hidden>
  <h1>Hidden main element</h1>
  <!-- content -->
</main>

Section lacks heading. Consider using “h2”-“h6” elements to add identifying headings to all sections.

The <section> element can be used to define sections of a document, like chapters, tabbed content, etc. Consider using a heading element (any of <h2> to </h6>) to present each section. Example:

<h1>All about guitars</h1>
<section>
  <h2>Guitar types</h2>
  <p>Acoustic, electric, classical... we have them all!</p>
</section>
<section>
  <h2>Amplifiers</h2>
  <p>Analog, digital, portable...</p>
</section>

Stray start tag “section”.

The “Stray start tag “section”” error in the W3C HTML Validator typically occurs when a <section> tag appears in an unexpected location within your HTML document structure. This can happen if the <section> tag is not positioned correctly within the HTML5 content model.

Here’s a focused guide to fix this issue:

1. Check the Parent Element

Make sure the <section> tag is placed within elements where it is allowed. According to the HTML5 specification:

A <section> element should be placed within the <body> tag.
It should not be a direct child of an inline element or an element that does not support flow content.

2. Correct Nesting Within Elements

Ensure your HTML structure follows a logical hierarchy and that the <section> element is not incorrectly nested. This example shows a correct usage of the <section> tag:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Correct Usage of Section</title>
</head>
<body>
    <header>
        <h1>Page Title</h1>
    </header>
    
    <nav>
        <!-- Navigation links -->
    </nav>
    
    <main>
        <section>
            <h2>Section Title</h2>
            <p>Content for the first section.</p>
        </section>
        
        <section>
            <h2>Another Section Title</h2>
            <p>Content for the second section.</p>
        </section>
    </main>
    
    <footer>
        <p>Footer content</p>
    </footer>
</body>
</html>

3. Check for Mistaken Hierarchy

Verify whether the <section> tag is mistakenly placed inside elements that do not support it, such as directly inside a <p> tag or other inline elements. Correct any incorrect usage. For example this is incorrect usage because the <section> tag is placed after the closing <body> tag:

Incorrect:

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Sample page</title>
</head>
<body>
  <h1>Main title</h1>
  <p>Some content</p>
</body>
</html>

<section>
  <h2>Incorrect Section</h2>
  <p>This section should not be after the closing body tag.</p>
</section>

Correct:

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Sample page</title>
</head>
<body>
  <h1>Main title</h1>
  <p>Some content</p>

  <section>
    <h2>Correct Section</h2>
    <p>This section is fine.</p>
  </section>
</body>
</html>

Summary

Ensure your <section> tags are used within the <body> tag and other allowed elements.
Maintain a logical hierarchy in your HTML document.
Avoid placing <section> tags inside inline elements like <p>.

Following these steps should resolve the “Stray start tag “section”” error in your HTML document. Validate your HTML again after making these corrections to ensure the issue is resolved.

The “main” role is unnecessary for element “main”.

The main landmark role is used to indicate the primary content of a document. It can be added to an element by using role="main", but instead it’s preferable to just use the <main> element. In that case, it’s unnecessary to make the main role explicit. Examples:

<div role="main">
  <!-- this is a valid way to define a main role -->
</div>

<main>
   <!-- but this is shorter and uses correct semantic HTML  -->
</main>