HTML Checking for Large Sites
Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
<br> tag inserts a line break, and it’s self-closing so you can use either
</br> is invalid.
<br> tag is a void element, it doesn’t need a closing tag, so
<br> is preferred to
First line<br> Second line is also valid but discouraged.<br/> Third line is invalid</br>