Description corresponding of "Any other attribute" of embed element is not found

[mtrootyy]

4.8.6 The embed element
  ......
  Content attributes:
    ......
    Any other attribute that has no namespace (see prose).

Description corresponding of "see prose" is not found.

[annevk]

It seems the relevant sentence got removed in 2014: d8c6447.

At least I can't find

  <p>Any namespace-less attribute other than <code data-x="attr-embed-name">name</code>, <code
  data-x="attr-embed-align">align</code>, <code data-x="attr-embed-hspace">hspace</code>, and <code
  data-x="attr-embed-vspace">vspace</code> <!-- when editing, see also note below --> may be
  specified on the <code>embed</code> element, so long as its name is <span>XML-compatible</span>
  and contains no <span>uppercase ASCII letters</span>. These attributes are then passed as
  parameters to the <span>plugin</span>.</p>

  <p class="note">All attributes in <span>HTML documents</span> get lowercased automatically, so the
  restriction on uppercase letters doesn't affect such documents.</p>

  <p class="note">The four exceptions are to exclude legacy attributes that have side-effects beyond
  just sending parameters to the <span>plugin</span>.</p>

  <div w-nodev>

  <p>The user agent should pass the names and values of all the attributes of the <code>embed</code>
  element that have no namespace to the <span>plugin</span> used, when one is instantiated.</p>

  <p>The <code>HTMLEmbedElement</code> object representing the element must expose the scriptable
  interface of the <span>plugin</span> instantiated for the <code>embed</code> element, if any. At a
  minimum, this interface must implement the <dfn data-x="dom-embed-caller">legacy caller
  operation</dfn>. (It is suggested that the default behavior of this legacy caller operation, e.g.
  the behavior of the default plugin's legacy caller operation, be to throw a
  <code>NotSupportedError</code> exception.)</p>

after that.

Now given #6003 and the implementation state of this feature in browsers today it might not really be worth saving.

Overall we've been slowly leaning towards marking the embed and object elements as obsolete.