Posted by John Salerno on 02/05/06 04:42

John Salerno wrote:
> What exactly does this mean:
>
> "Document sent as text/html are handled as tag soup [1] by most UAs.
> This means that authors are not checking for validity, and thus
> most XHTML documents on the web now are invalid. Therefore the main
> advantage of using XHTML, that it has to be valid, is lost of the
> document is then sent as text/html."
>
> To me it sounds like he is saying that *any* document written in XHTML
> and then served as text/html is invalid. But is that really the case? Or
> is he saying that the document *could* be invalid because it could still
> be prone to the methods of HTML (e.g., no closing tags, etc.)?
>
> I assume if you validate your XHTML, then simply serving it as text/html
> doesn't harm it, right? It doesn't suddenly make it "invalid," does it?
> (Perhaps in a strict sense it does, because it's not truly XHTML, but as
> far as the actually words in the document themselves, they are still
> valid, right? And if it was then served as application/xhtml-xml, it
> would be valid, correct?)

One more quote, this time from Andy from this newsgroup:

"However (the bad news) this is an XML technique and so only works with
XHTML documents that are XML documents, not the Appendix C XHTML non-XML
documents we've already mentioned as being the only ones that are yet
ready for use on the web. You can still use these techniques, but it's
not simple, much of your audience may have problems with them, and
compatibility issues are significant."

So basically these last three posts of mine are asking the same
question: why is "Appendix C" XHTML considered invalid? What more is
there to writing real XHTML than simply starting with the basic rules
(lower-case, proper nesting, closing tags, etc.)?

Obviously you can eventually include other XML namespaces, but for now,
why is it said that documents written in Appendix C XHTML will
eventually be invalid when actually served as application/xhtml+xml?

Thanks!

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