some of the important lines
height attributes on
object are no longer allowed to contain percentages. They are also not allowed to be used to stretch the image to a different aspect ratio than its intrinsic aspect ratio.
strong element now represents importance rather than strong emphasis.
autofocus attribute can be specified on the
input (except when the
type attribute is
button elements. It provides a declarative way to focus a form control during page load. Using this feature should enhance the user experience as the user can turn it off if the user does not like it, for instance.
<input type=email placeholder="email@example.com">
form attribute for
fieldset elements allows for controls to be associated with a form. These elements can now be placed anywhere on a page, not just as descendants of the
form element, and still be associated with a
<label>Email: <input type=email form=foo name=email> </label> <form id=foo></form>