doctype

I. Description

The DOCTYPE declaration is the first thing in every HTML document. It consists of the 14 characters <!DOCTYPE html>. The DOCTYPE declaration is mandatory and MUST be the first line of every HTML document.

II. Examples

<!DOCTYPE html>
<html>
    <head>
        <title>Example Page</title>
    </head>
    <body>
        <h1>Example HTML Page</h1>
        <p>The DOCTYPE declaration for this HTML document appears on line 1.</p>
    </body>
</html>