Re: [ietf-types] Registration of media typeimage/svg+xml

[Chris Lilley <[e-mail]>]

This is an updated registration request, incorporating some feedback
from Paul Libbrecht <[e-mail]>, Mark Baker
<[e-mail]>, Henry S. Thompson <[e-mail]>
and Alexey Melnikov <[e-mail]>.

Type name:

    image
    
Subtype name:

    svg+xml
    
Required parameters:

    None.
    
Optional parameters:

    charset

    Same as application/xml media type, as specified in [RFC3023] or
    it's successors.
    
Encoding considerations:

    Same as for application/xml. See [RFC3023], section 3.2 or it's
    successors.
    
Security considerations:

    As with other XML types and as noted in [RFC3023] 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.

    SVG documents may be transmitted in compressed form using gzip
    compression. For systems which employ MIME-like mechanisms, such
    as HTTP, this is indicated by the Content-Encoding or
    Transfer-Encoding header, as appropriate; for systems which do
    not, such as direct filesystem access, this is indicated by the
    filename extension and by the Macintosh File Type Codes. In
    addition, gzip compressed content is readily recognised by the
    initial byte sequence as described in [RFC1952] section 2.3.1.

    Several SVG elements may cause arbitrary URIs to be referenced. In
    this case, the security issues of [RFC3986], section 7, should be
    considered.

    In common with HTML, SVG documents may reference external media
    such as images, audio, video, style sheets, and scripting
    languages. Scripting languages are executable content. In this
    case, the security considerations in the Media Type registrations
    for those formats shall apply.

    In addition, because of the extensibility features for SVG and of
    XML in general, it is possible that "image/svg+xml" may describe
    content that has security implications beyond those described
    here. However, if the processor follows only the normative
    semantics of this specification, this content will be outside the
    SVG namespace and shall 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:

    This specification describes processing semantics that dictate
    behavior that must be followed when dealing with, among other
    things, unrecognized elements and attributes, both in the SVG
    namespace and in other namespaces.

    Because SVG is extensible, conformant "image/svg+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.

    SVG has a published Test Suite and associated implementation
    report showing which implementations passed which tests at the
    time of the report. This information is periodically updated as
    new tests are added or as implementations improve.

Published specification:

    This media type registration is extracted from Appendix P of the
    SVG 1.1 specification. http://www.w3.org/TR/SVG/

Applications that use this media type:

    SVG is used by Web browsers, often in conjunction with HTML; by
    mobile phones and digital cameras, as a format for interchange of
    graphical assets in desk top publishing, for industrial process
    visualization, display signage, and many other applications which
    require scalable static or interactive graphical capability.

Additional information:

    Magic number(s):
    File extension(s):
        svg, svgz (if gzip-compressed)
    Macintosh file type code(s):
        "svg " (all lowercase, with a space character as the fourth
        letter), "svgz" (all lowercase, if gzip-compressed).
    Macintosh Universal Type Identifier code:
        org.w3c.svg conforms to public.image and to public.xml
    Windows Clipboard Name:
        "SVG Image"
    Fragment Identifiers
        For documents labeled as application/svg+xml, the fragment
        identifier notation is that for application/xml, as specified
        in RFC 3023 or its successors, plus the SVG-specific SVG Views
        syntax described in the SVG specification.

Person & email address to contact for further information:

    Chris Lilley, Doug Schepers ([e-mail])

Intended usage:

    COMMON

Restrictions on usage:

    None
    
Author:

    The SVG specification is a work product of the World Wide Web Consortium's SVG Working Group.

Change controller:

    The W3C has change control over this specification.






-- 
 Chris Lilley   Technical Director, Interaction Domain                 
 W3C Graphics Activity Lead, Fonts Activity Lead
 Co-Chair, W3C Hypertext CG
 Member, CSS, WebFonts, SVG Working Groups