Registration request for MIME media type tag 3gpp-ims+xml

John-Luc Bakker jbakker at
Tue Jul 29 23:08:04 CEST 2008

Hi Bjoern, 

Thank you for your attention to this matter!
I copied the original text following the "optional parameters" heading and made some significant reductions and clarifications:

Optional parameters: 
"charset"   the parameter has identical semantics to the charset parameter of the "application/xml" media type as specified in RFC 3023.
"sv" or "schemaversion" the parameter's value indicates versions corresponding to 3GPP IM CN Subsystem XML schema documents as specified in 3GPP TS 24.228.

Would such be a more suitable text for inclusion in the IANA registry for Application Media Types?

Kind regards,


-----Original Message-----
From: Bjoern Hoehrmann [mailto:derhoermi at] 
Sent: Friday, July 11, 2008 1:07 PM
To: John-Luc Bakker
Cc: John M Meredith; ietf-types at; georg.mayer at; Frederic Firmin; Andrew Allen; Atle Monrad; christer.holmberg at ERICSSON.COM
Subject: Re: Registration request for MIME media type tag 3gpp-ims+xml 

* John-Luc Bakker wrote:
>In SIP, use of the accept header field and the content-type header
>field provides open and extensible data typing and type negotiation
>The Accept header field (RFC 3261, section 20.1) of a SIP request
>indicates the formats accepted by the SIP UAC. MIME media type and their
>parameters can be listed in the Accept header for that purpose. Thus,
>what the SIP UAC is indicating are the variations of the MIME type (i.e.
>application/3gpp-ims+xml) that are accepted.
>The Content-Type header field (RFC 3261, section 20.15) can be found in
>a SIP response and request and indicates the MIME media type of the SIP
>message-body. MIME media type and their parameters can be listed in the
>Content-Type header field for that purpose. Thus, it provides a hint to
>the recipient as to how to decode the material and, in particular in the
>case of "application/3gpp-ims+xml", which schema to validate the body
>The semantics of the parameter are those of the header field the
>parameter is placed in.

Thanks, I see now where my confusion is coming from. From my perspective
the semantics of the parameter and its value are the same in both cases,
and was under the impression that, as an example, you can specify ranges
in the parameter when used in 'Accept' and must specify a single version
in the 'Content-Type' parameter.

I think it would be preferable if this could be reworded to avoid this
confusion; but I can't immediately offer better text, other than some-
thing more unspecific ala "Indicates relevant 3GPP IM CN Subsystem XML
versions (e.g., that an implementation or document conforms to)" which
I am not sure you would find an improvement.
Björn Höhrmann · mailto:bjoern at ·
Weinh. Str. 22 · Telefon: +49(0)621/4309674 ·
68309 Mannheim · PGP Pub. KeyID: 0xA4357E78 · 

This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful.

More information about the Ietf-types mailing list