HTML Guide
Free site validation
Find out what web pages on your sites are affected by HTML issues.
An HTML tag could not be parsed, most probably because of a typo.
Related W3C validator issues
A slash character (/), normally used for self-closing tags, has been found in an unexpected place for a tag, and the validator has decided to ignore it and treat is as a start tag instead.
HTML tags can go in pairs (start tag, end tag) or be self-closing, for example:
<p>This is a paragraph with a start and end p tag</p>
<img src="image.jpg" alt="This is an image with a self-closing tag" />In HTML5, the ending slash and the preceding space is optional for self-closing tags so all of these are valid:
<img src="image.jpg" alt="This is an image with a self-closing tag" />
<img src="image.jpg" alt="This is an image with a self-closing tag"/>
<img src="image.jpg" alt="This is an image with a self-closing tag">A common mistake is including a slash tag on a start tag, as in the following example. If the Nu HTML checker encounters that, it will ignore the slash and just treat the tag as a start tag.
<select />
<option value="1">one</option>
</select>