Question about validating wphostingblog.nl/wordpress-hosting-vergelijken/ - elements not allowed

Hi,

I just validated this URL:
http://wphostingblog.nl/wordpress-hosting-vergelijken/

Some errors came up and two of them I have a question about. What does
'element not allowed' exactly mean?

I know the elements are not allowed the way the are being used right now.
But the real question is: can they harm my website? Will some browsers
maybe show the webpage differently because of the poorly placed elements?

The exact messages were:

- Attribute xmlns:v not allowed here.

- Element style
<http://www.w3.org/html/wg/drafts/html/master/single-page.html#the-style-element>
not allowed as child of element div
<http://www.w3.org/html/wg/drafts/html/master/single-page.html#the-div-element>
in this context. (Suppressing further errors from this subtree.)

The website was built using WordPress. Should I ask the developers of the
theme to resolve these errors? Or can I accept them because they won't hurt
my WordPress website?

Kind regards,


Rick
http://wphostingblog.nl/