Re: Registration of media type application/ttaf+xml

DFXP's mime type is formally based on RFC 3023 [XML Media Types], which
specifies ".xml" as file name extension (see Section 3.2 of that RFC, under
Additional Information);
On Tue, Oct 6, 2009 at 9:03 AM, Silvia Pfeiffer
<silviapfeiffer1@gmail.com>wrote:

> I am concerned about the lack of a additional information typically
> used in mime type registration RFCS, see e.g.
> http://www.rfc-editor.org/rfc/rfc3839.txt (for 3gpp) or
> http://tools.ietf.org/html/rfc4337 (mpeg4) or
> http://www.ietf.org/rfc/rfc5334.txt (ogg):
>
> Magic number(s):  (probably not relevant)
> File extension(s):
> Macintosh File Type Code(s):
>
> I think it is important that we specify a common file extension and a
> mac file type code so as not to create confusion in the market with
> some people creating .dfxp , some creating .xml and some creating
> whatever they think is appropriate. This will make it very difficult
> for example for Web servers to serve the correct mime types, since
> they tend to do so based on file extensions.
>
> My suggestion is:
>
> File extension: .dfxp (I think four letters is reasonable nowadays,
> even for windows?)
>
> Mac file type code: DFXP
>
>
> Best Regards,
> Silvia.
>
>
> On Thu, Oct 1, 2009 at 6:46 AM, Philippe Le Hegaret <plh@w3.org> wrote:
> > The following media type registration will be submitted to
> > the IESG for review, approval, and registration with IANA (as per [1]).
> >
> > At this point, we would appreciate comments on this registration
> > information.  If you see any problems, please let us know.
> >
> >
> > Regards,
> >
> > Philippe
> >
> > [1] http://www.w3.org/2002/06/registering-mediatype
> >
> > [[
> >
> > This appendix registers a new MIME media type, "application/ttaf+xml"
> > in conformance with [1144]BCP 13 and [1145]W3CRegMedia. The information
> > in this appendix is being submitted to the Internet Engineering
> > Steering Group (IESG) for review, approval, and registration with the
> > Internet Assigned Numbers Authority (IANA).
> >
> >    [1144] http://www.ietf.org/rfc/rfc4288.txt
> >    [1145] http://www.w3.org/2002/06/registering-mediatype.html
> >
> >   MIME media type name:
> >          application
> >
> >   MIME subtype name:
> >          ttaf+xml
> >
> >   Required parameters:
> >          None.
> >
> >   Optional parameters:
> >          The encoding of a TT AF document must be determined by the
> >          XML encoding declaration. This has identical semantics to the
> >          application/xml media type in the case where the charset
> >          parameter is omitted, as specified in [1146][XML Media],
> >          Sections 8.9, 8.10 and 8.11.
> >
> >          The document profile of a TT AF document may be specified
> >          using an optional profile parameter, which, if specified, the
> >          value of which must adhere to the syntax and semantics of
> >          ttp:profile parameter defined by Section [1147]6.2.8
> >          ttp:profile of the published specification.
> >
> >   Encoding considerations:
> >          Same for application/xml. See [1148][XML Media], Section 3.2.
> >
> >   Restrictions on usage:
> >          None.
> >
> >   Security considerations:
> >          As with other XML types and as noted in [1149][XML Media]
> >          Section 10, repeated expansion of maliciously constructed XML
> >          entities can be used to consume large amounts of memory,
> >          which may cause XML processors in constrained environments to
> >          fail.
> >
> >          In addition, because of the extensibility features for TT AF
> >          and of XML in general, it is possible that
> >          "application/ttaf+xml" may describe content that has security
> >          implications beyond those described here. However, if the
> >          processor follows only the normative semantics of the
> >          published specification, this content will be outside TT AF
> >          namespaces and may be ignored. Only in the case where the
> >          processor recognizes and processes the additional content, or
> >          where further processing of that content is dispatched to
> >          other processors, would security issues potentially arise.
> >          And in that case, they would fall outside the domain of this
> >          registration document.
> >
> >   Interoperability considerations:
> >          The published specification describes processing semantics
> >          that dictate behavior that must be followed when dealing
> >          with, among other things, unrecognized elements and
> >          attributes, both in TT AF namespaces and in other namespaces.
> >
> >          Because TT AF is extensible, conformant
> >          "application/ttaf+xml" processors must expect that content
> >          received is well-formed XML, but it cannot be guaranteed that
> >          the content is valid to a particular DTD or Schema or that
> >          the processor will recognize all of the elements and
> >          attributes in the document.
> >
> >   Published specification:
> >          This media type registration is extracted from Appendix
> >          [1150]D Media Type Registration of the [1151]Timed Text (TT)
> >          Authoring Format 1.0 - Distribution Format Exchange Profile
> >          (DFXP) specification.
> >
> >    [1151] http://www.w3.org/TR/ttaf1-dfxp/
> >
> >   Additional information:
> >          None.
> >
> >   Person & email address to contact for further information:
> >          Glenn Adams (public-tt@w3.org)
> >
> >   Intended usage:
> >          COMMON
> >
> >   Author/Change controller:
> >          The published specification is a work product of the World
> >          Wide Web Consortium's Timed Text (TT) Working Group. The W3C
> >          has change control over this specification.
> >
> > ]]
> > http://www.w3.org/TR/ttaf1-dfxp/#media-type-registration
> >
> >
> >
> >
> >
>