HTML Checking for Large Sites
Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
In the days before HTML5, named anchors were used as a way to provide a link to a specific section of a document, for example:
<h2>
<a name="section-5">Section 5</a>
</h2>
Now in HTML5, the name attribute is obsolete for <a> tags, and instead, you can use the id attribute of any element (not just <a>) as a way to navigate directly to it, for example:
<h2 id="section-5">Section 5</h2>Learn more:
Related W3C validator issues
The <option> element no longer accepts a name attribute, which is now obsolete.
Example:
<select id="pet-select">
<option value="">--Please choose an option--</option>
<option value="dog">Dog</option>
<option value="cat">Cat</option>
<option value="hamster">Hamster</option>
</select>The id attribute of an HTML element, used to identify the element when linking, scripting or styling, must be unique in the whole document and must not contain whitespace.
Technically, in HTML5, the value for an id attribute may contain any character, except whitespace characters. However, to avoid inadvertent errors, only ASCII letters, digits, _, and - should be used and the value for an id attribute should start with a letter.
A <meta> tag has been found that is either malformed, or in a bad place within the document. Check its attributes and context.
For example, the following HTML contains a valid <meta> tag that is raising an issue because of bad context, caused by an <img> tag that shouldn’t be there:
<!DOCTYPE html>
<html lang="">
<head>
<title>Test</title>
<img src="photo.jpg" alt="A smiling cat" />
<meta name="description" content="Description of this page" />
</head>
<body>
<p>Some content</p>
</body>
</html>If we fix that document and move the <img> tag within the body, the issue raised about <meta> disappears because it’s now in a valid context:
<!DOCTYPE html>
<html lang="">
<head>
<title>Test</title>
<meta name="description" content="Description of this page" />
</head>
<body>
<p>Some content</p>
<img src="photo.jpg" alt="A smiling cat" />
</body>
</html>The id attribute is used to identify a single element within a document, it’s not required, but if used it must be unique, and must not be an empty string.
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IDs for HTML elements can’t be blank.
The name attribute is required for all input elements.
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The <label> element represents a caption in a document, and it can be associated with a form input using the for attribute, which must be an ID. Document IDs cannot contain whitespace.
Example:
<form>
<label for="user_name">Name</label>
<input type="text" id="user_name" />
</form>A <pattern> element has been found with an invalid ID. Check the format of the ID and ensure it does not start with a digit, full stop (.) or hyphen (-).
The <pattern> element is used within <svg> elements, which use XML 1.0 syntax. That syntax specifies that valid IDs only include designated characters (letters, digits, and a few punctuation marks), and do not start with a digit, a full stop (.) character, or a hyphen-minus (-) character.
The id attribute is used to identify a single element within a document, and is required to be unique. Check the document for repeated IDs.
Element IDs in an HTML document must be unique. The HTML validator is indicating the first occurrence of an ID that is repeated. Check the details for that issue to see web pages affected, and the elements within them, to fix that ID repetition.
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