RE: text/xhtml+xml vs. application/xhtml+xml

> You can construct HTML that can be read without an HTML 
> processor of any sort. But few if any agents that emit 
> text/html actually do this. 

Right, and you need to ask yourself why that is.

> > To get back to ground zero, one must ask why one is exchanging 
> > XML in the first place. If is as a structured peice of text, 
> > then text/* is fine.
> 
> No it isn't, because that's not what the top-level text type is 
> for. The intent of the text type is to label material that can 
> sensible be presented to people without any processing.

I think there is a lot of XML content that meets those criteria.
There is obviously also a *lot* that doesn't (SOAP messages etc.)

> You seem to think that the top-level text type label is intended to label
> structured text, but that's just not what it is for.

No. I understand quite well what the intent of text/* is. I
should note that *all* text is somewhat structured (even this
message which will be sent text/plain). Many XML documents doi
little more than make the inherent structure explicit, and for
such documents, text/xml is fine.

> The +xml suffix is intended to make XML detectable even when 
> the specific type isn't known. 

Right, which just gives one more level of default behaviour. At the
end of the day, people are going to use XML as they see fit, and
there will be *many* application specific uses of XML. Most of those
applications can, and should use application/foo or application/foo+xml.
In the latter case, the main benefit is that if the processor doesn't
know about application/foo, it can do *something*.

Bottom line: text/xml, application/foo+xml and (to a lesser degree)
application/xml are all useful. We should provide them all and give
people clear guidelines on their use so that we can avoid the abuse
we see with text/html.