Useful link: character entity references in html5

As you probably notices HTML4 and HTML5 looks bit different.
For example: It is affect character entity references a little bit.

Most common character entity references in  HTML5  that You will need change:

•   " Change  "  to  " 
•  & Change  &  to  &
•  < Change &lt;  to  &#60;
•  > Change &gt;  to  &#62;
•    (space) Change &nbsp;  to  &#160;
•  © Change &copy;  to  &#169;
•  ® Change &reg;  to  &#174;
•  ™ Change &trade;  to  &#8482;

If you need know more,there is fantastic page with all character entity references in  HTML5:  http://dev.w3.org/html5/html-author/charref