Comment:
From http://lists.w3.org/Archives/Public/public-comments-wcag20/2006May/0120.html
Text alternatives
[INS: [For n] :INS] on-text content that is multimedia... it is important that users know what it is when they encounter it on a page so they can decide what action if any they want to take with it. A text alternative that describes the multimedia and/or gives its title is therefore provided.
How do I do that with, say, embed, which permits no fallback content? (Of course there's noembed, but, since all graphical browsers understand embed, noembed content will never be displayed. In any event, there is no actual or official specification for embed and especially noembed.) Does this not mean I have to label each video in plain text?
We have moved the technique on using noembed with embed to advisory. General techniques are available which describe alternative methods on providing text alternatives for EMBED.