[media-types] Re: Clarification about text/xml subtypes

Hi Andrea,

Based on what I read, I would suggest to register application/opml+xml.

And note the deprecated aliases: text/x-opml

I’m not an XML expert, and possibly there are some critical details of
text/ that I am not aware of that preclude the suggestion above.

Inline for the rest:


On Thu, Mar 19, 2026 at 11:05 PM Andrea Pappacoda <[email protected]> wrote:

> Hi all!
>
> I'd like to ask what might be a dumb question about text/xml subtypes.
>
> I notice that there are almost no registered text/xml subtypes; all of
> them seem to be subtypes of application/xml (like application/rdf+xml).
>
> I also notice that Section 4.1.1 of RFC 2046 says that text/* types MUST
> use a CRLF sequence to represent line breaks.
>
> This leads me to think that text/xml subtypes must use CRLF for line
> breaks, instead of simply LF. Is my understanding correct?


I don’t know the answer to this, but I would guess sorta… I don’t know what
a text/xml subtype would be, since xml is the subtype in the example and
+xml is a structured suffix for application subtypes that use xml.


>
> Also, is there a particular reason why there are no text/xml subtypes?


Do you mean that there are no +xml based text/ subtypes?
IIRC +xml comes from application/xml … so there are no text subtypes that
use it… I think?


>
> This all comes from a particular GitHub issue[1] about the possibility
> of registering a media type for the OPML file format[2][3], which is
> based on XML. The format currently uses either the text/x-opml media
> type, application/xml or text/xml media types. There have been proposals
> of registering text/opml+xml, or using the vendor or peronal trees, but
> seeing the lack of any registered text/xml subtype got me wondering why.
>
> Note that I'm aware of the historical charset considerations for
> text/xml vs application/xml, but they are not what I'm confused about.


I’m not aware of these, so you probably know more than me, hopefully
someone more knowledgeable will be able to answer your questions above.


>
> Please Cc me in replies as I'm not subscribed. Thanks! Bye :)
>
> [1]: https://github.com/scripting/opml.org/issues/20
> [2]: https://en.wikipedia.org/wiki/OPML
> [3]: https://opml.org/spec2.opml
>
> P.S. I had originally sent this mail to <[email protected]>, but
> since discovered via 6838bis that the new mail address is @ietf.org. In
> case this got delivered twice, I'm sorry.
>
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