W3C: "there is no attribute 'HEIGHT'"

<table height=100%>
  <tr>
    <td>stuff</td>
  </tr>
</table>

I do this all the time, and so do countless of other people.  But apparently, table doesn't support the "height" attribute, officially that is.  It looks like all browsers support it just fine, but for W3C religeous reasons, one must use a style (inline or otherwise) to do it like this:

<table style="height: 100%;">
  <tr>
    <td>stuff</td>
  </tr>
</table>

ps. TD doesn't "support" background either, officially.
One must do:

<td style="background: url('some/image');">