HTML Elements Valid DOCTYPES
HTML <!DOCTYPE>
The HTML Document Type
All HTML documents must start with a <!DOCTYPE> declaration.
The declaration is not an HTML tag. It is an "information" to the browser about what document type to expect.
In HTML5, the <!DOCTYPE> declaration is simple:
<!DOCTYPE html>
In older documents (HTML 4 or XHTML), the declaration is more complicated because the declaration must refer to a DTD (Document Type Definition).
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
You can read more about document types in the <!DOCTYPE> reference.
Valid HTML Elements in Different DOCTYPES
TagHTML 5HTML 4XHTML<a>YesYesYes<abbr>YesYesYes<acronym>NoYesYes<address>YesYesYes<applet>NoYesNo<area>YesYesNo<article>YesNoNo<aside>YesNoNo<audio>YesNoNo<b>YesYesYes<base>YesYesYes<basefont>NoYesNo<bdi>YesNoNo<bdo>YesYesNo<big>NoYesYes<blockquote>YesYesYes<body>YesYesYes<br>YesYesYes<button>YesYesYes<canvas>YesNoNo<caption>YesYesYes<center>NoYesNo<cite>YesYesYes<code>YesYesYes<col>YesYesNo<colgroup>YesYesNo<datalist>YesNoNo<dd>YesYesYes<del>YesYesNo<details>YesNoNo<dfn>YesYesYes<dialog>YesNoNo<dir>NoYesNo<div>YesYesYes<dl>YesYesYes<dt>YesYesYes<em>YesYesYes<embed>YesNoNo<fieldset>YesYesYes<figcaption>YesNoNo<figure>YesNoNo<font>NoYesNo<footer>YesNoNo<form>YesYesYes<frame>NoNoNo<frameset>NoYesNo<h1> to <h6>YesYesYes<head>YesYesYes<header>YesNoNo<hr>YesYesYes<html>YesYesYes<i>YesYesYes<iframe>YesYesNo<img>YesYesYes<input>YesYesYes<ins>YesYesNo<kbd>YesYesYes<label>YesYesYes<legend>YesYesYes<li>YesYesYes<link>YesYesYes<main>YesNoNo<map>YesYesNo<mark>YesNoNo<meta>YesYesYes<meter>YesNoNo<nav>YesNoNo<noframes>NoYesNo<noscript>YesYesYes<object>YesYesYes<ol>YesYesYes<optgroup>YesYesYes<option>YesYesYes<output>YesNoNo<p>YesYesYes<param>YesYesYes<pre>YesYesYes<progress>YesNoNo<q>YesYesYes<rp>YesNoNo<rt>YesNoNo<ruby>YesNoNo<s>YesYesNo<samp>YesYesYes<script>YesYesYes<section>YesNoNo<select>YesYesYes<small>YesYesYes<source>YesNoNo<span>YesYesYes<strike>NoYesNo<strong>YesYesYes<style>YesYesYes<sub>YesYesYes<summary>YesNoNo<sup>YesYesYes<table>YesYesYes<tbody>YesYesNo<td>YesYesYes<textarea>YesYesYes<tfoot>YesYesNo<th>YesYesYes<thead>YesYesNo<time>YesNoNo<title>YesYesYes<tr>YesYesYes<track>YesNoNo<tt>NoYesYes<u>YesYesNo<ul>YesYesYes<var>YesYesYes<video>YesNoNo<wbr>YesNoNo
