Not agree with markup validation service

Dear sir/madam,

I have validated my web page ( www.diing.es ) using markup validation
service and i don´t understand the mistakes that the service is marking:


As per my knowledge this is not an error. Could you please explain me where
the mistake is?
I want to use the validation certificate in my web page but I can´t due to
this issue.
Thanks for your help in advance.

Awaiting your soonest reply.

Best regards, 

Sergio Pompa Garvía
Front-End Developer / UX
Móvil: 661 76 15 86
e-mail: spompag@gmail.com <mailto:spompag@gmail.com>
Sergio Pompa Garvia | LinkedIn
<http://www.linkedin.com/pub/sergio-pompa-garvia/6a/491/975>
@Sergio_Pompa_G <https://twitter.com/Sergio_Pompa_G>

Received on Friday, 16 May 2014 21:27:13 UTC