HTML Guide
All HTML documents must start with a <!DOCTYPE> (Document Type Declaration), that informs browsers about the type and version of HTML used to build the document. In HTML5, this is simply <!DOCTYPE html> and must appear at the start of the document.
Here is an example of a minimal HTML document, including the Document Type Declaration at its start:
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
</head>
<body>
<p></p>
</body>
</html>Related W3C validator issues
Rocket Validator checks HTML on your sites using the latest version of W3C Validator Nu HTML Checker, which is intended for HTML5 documents.
The page scanned is using an “almost standards mode” doctype, instead of the expected <!DOCTYPE html>. While the almost standards mode was used in the transition to HTML5, you should consider moving to the HTML5 standard.
HTML documents are expected to start with a first line containing the Document Type Declaration, that defines the HTML version used. Since HTML5, it’s just <!DOCTYPE html>, which must appear before the start <html> tag.
Here’s an example of a minimal HTML5 document:
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
</head>
<body>
<p></p>
</body>
</html>Rocket Validator checks HTML on your sites using the latest version of W3C Validator Nu HTML Checker, which is intended for HTML5 documents.
The page scanned is using an obsolete doctype, instead of the expected <!DOCTYPE html>.
HTML documents are expected to start with a first line containing the Document Type Declaration, that defines the HTML version used. Since HTML5, it’s just <!DOCTYPE html>, which must appear before the start <html> tag.
Here’s an example of a minimal HTML5 document:
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
</head>
<body>
<p></p>
</body>
</html>An end tag for X has been found that does not correspond to a previous open tag. This usually happens when you close the same tag twice, for example:
<ul>
<li>item</li>
</ul>
</ul>A <head> start tag has been found in an unexpected place in the document structure. Check that the <head> section appears before the <body> section, and that is not duplicated.
The <head> section of an HTML document is the container of metadata about the document, and must appear before the <body> section. A common cause of this issue is duplicated <head> sections.
Here is an example of a minimal HTML document structure:
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
</head>
<body>
<p></p>
</body>
</html>A stray start tag <html> has been found in the document. As this tag defines the start of the whole HTML document, it should appear only once.
The “Stray start tag noscript“ error in the W3C HTML Validator indicates that the <noscript> tag has been used incorrectly or is placed in an invalid location within your HTML document.
The <noscript> tag is used to define alternative content for users who have disabled JavaScript in their browsers or for browsers that do not support JavaScript.
Common Causes:
- Position of <noscript>: The <noscript> tag should be placed correctly within sections where it is allowed.
- Nested Improperly: The <noscript> tag should not be placed inside other tags where it is not valid.
Correct Usage:
-
Within <head>:
<head> <title>Example Page</title> <script> // Some JavaScript code </script> <noscript> <style> /* Alternative styling if JavaScript is disabled */ </style> </noscript> </head> -
Within <body>:
<body> <h1>Welcome to the Example Page</h1> <script> // Some JavaScript code </script> <noscript> <p>JavaScript is disabled in your browser. Please enable JavaScript for the full experience.</p> </noscript> </body>
Fixing the Issue:
-
Inside Existing Tags: Ensure the <noscript> tag is not placed inside other tags where it cannot be parsed correctly.
<!-- Incorrect --> <div> <noscript> <p>JavaScript is disabled in your browser.</p> </noscript> </div> <!-- Correct --> <noscript> <div> <p>JavaScript is disabled in your browser.</p> </div> </noscript> -
Placement in Body or Head: Verify that the <noscript> tag is placed inside the <body> or <head> based on what content it’s providing a fallback for.
<!-- Incorrect (inside an illegal tag) --> <div> Some content <noscript><p>JavaScript is disabled in your browser.</p></noscript> </div> <!-- Correct --> <div>Some content</div> <noscript><p>JavaScript is disabled in your browser.</p></noscript>
Summary:
- Place <noscript> only within accepted sections (<head> or <body>).
- Avoid nesting <noscript> inside other tags improperly.
A <script> start tag has been found in an unexpected place in the document structure. Check that the <script> section appears within the <head> or <body> sections.
Here’s an example of a script inserted in the head of the document:
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
<script>
console.log("Hello from the head");
</script>
</head>
<body>
<p></p>
</body>
</html>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.