ciao, nel sito web ho inserito il seguente codice per condividere un filmato youtube.

<iframe width="560" height="315" src="http://www.youtube.com/embed/_0srvrcfr-U?&autoplay=1&rel=0" frameborder="0" allowfullscreen autoplay></iframe>


Purtroppo w3c (markup validation service) restituisce 11 errori e 6 warning

ne riporto solo alcuni:

Line 326, Column 15: there is no attribute "width"
<iframe width="560" height="315" src="http://www.youtube.com/embed/_0srvrcfr-U?…

Line 326, Column 28: there is no attribute "height"
<iframe width="560" height="315" src="http://www.youtube.com/embed/_0srvrcfr-U?…

Line 326, Column 38: there is no attribute "src"
<iframe width="560" height="315" src="http://www.youtube.com/embed/_0srvrcfr-U?…

Line 326, Column 81: general entity "autoplay" not defined and no default entity
…://www.youtube.com/embed/_0srvrcfr-U?&autoplay=1&rel=0" frameborder="0" allowf…
✉
This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.


Qual é il problema? Com é possibile che un codice di youtube penalizza il sito abbassando la % seo?

Vi ringrazio per la collaborazione