nbsp; and other common entities do not validate as HTML5!

The only built-in entities in XML are &, <, >, " and ' XHTML added the others via a DTD that is not a part of HTML5. As such, validators will report them as errors.

Safe replacements are the decimal notation: &#160; or the character itself U+00A0;

Quite a few other common symbols are not available without similar changes.

  • &lt; = &#60;
  • &gt; = &#62;
  • &amp; = &#38;
  • &apos; = &#39;
  • &quot; = &#34;
  • &nbsp;&#160;
  • &copy; = &#169;
  • &reg; = &#174;
  • &trade; = &#8482;


CDATA markup of XHTML script and style tags

Ideally all JavaScript and CSS definitions should be external to the content of an HTML page, in some cases it’s simply not practical. If you’ve migrated to XHTML markup of your page, this can often lead to XML validation errors. The use of a CDATA escape can fix most issues, though you may have to cleanup some of the actual code to resolve other issues, particularly with some special characters that are expected to be encoded.

Here are a few examples of CDATA implementation in HTML tags:

<script type="text/javascript">
/* <![CDATA[ */
/* ]]> */

<script type="text/javascript">// <![CDATA[
// ]]>

<style type="text/css">
/* <![CDATA[ */
/* ]]> */

JavaScript TextNode for special characters

It can be difficult to create or output some characters as JavaScript TextNodes. Typically you might try to use the ampersand notation, unfortunately the ampersand itself gets escaped to & as such   becomes &nbsp; Use of the Unicode notation can easily resolve this issue.

Example for NBSP:
var nsbptextnode = document.createTextNode('\u00A0');