Very often in the header of our web pages, we specify the Content Type, Javascript and CSS file path, again, life is easier with HTML5.

Instead of <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

In HTML5, it can be just <meta charset="UTF-8">

It used to be :- <script type="text/javascript" src="jquery.js"></script>

In HTML5, redundant information "type=text/javascript" is no longer necessary, practically, Javascript is the only client side script alive.

Hence, <script src="jquery.js"></script> is sufficient.

Similarly, CSS receives the first class citizen treatment as javascript too. You can now forget about "type=text/css". Simply just <link rel="stylesheet" href="html-my.css">

If this is the way your <html> root looks like <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">

It is now as simple as <html lang="en">