[VE][108] onload attribute does not exist for < IMG>?

W3 describes "onload" event: " The onload event occurs immediately after a
page or an image is loaded.".  Please see at your page:
http://www.w3schools.com/jsref/jsref_onload.asp

This event attribute is essential for dealing with every loading element.
Processing image onload event through BODY onload event is not a good or
sufficient programming. All browsers support this attribute and I just can't
see why W3 contradicts it's itself and force developers to choose between
bad programming and forsaking W3 validation.

Hope it just an error indeed.

Error [108]: "there is no attribute X"

NOTE: Whenever possible, give the address of the document you were checking.