HTML Checking for Large Sites

A <div> tag has been found as a direct child of an <ul> tag, and this is not allowed. For example, <ul><div><li>item</li></div></ul> is not valid, but <ul><li><div>item</div></li></ul> is valid as the direct child of <ul> is <li>.

An </a> end tag has been found to violate nesting rules. <a> tags can’t include other <a> tags inside. Most probable cause is an unclosed <a> tag, like in this example:

<a href="one.html">Page 1
<a href="two.html">Page 2</a>

An end tag </strong> has been found in an incorrect place within the document, violating nesting rules. A common case is closing it before closing other nested tags, for example:

<!-- This line is incorrect as the <strong> tag was closed before the nested <a> tag -->
<strong><a href="#">link</strong></a>

<!--- This line is OK as every end tag respects the nesting rules -->
<strong><a href="#">link</a></strong>

An <a> tag can’t include other <a> tags inside. Most probable cause is an unclosed <a> tag, like in this example:

<a href="one.html">Page 1
<a href="two.html">Page 2</a>

A <label> tag can’t be used inside an <a> tag. Consider using other tags like <span>.

A <label> element cannot contain other <label> as a descendant. Check for nested elements or closing tags that may have been misinterpreted, for example:

<label>name</label></label>

The <caption> element specifies the caption (or title) of a table. It’s not allowed for a <caption> to contain another table.