serviceprovidermeta.xml

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<?rfc toc="yes"?>
<?rfc tocompact="yes"?>
<?rfc tocdepth="3"?>
<?rfc tocindent="yes"?>
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<?rfc comments="yes"?>
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<rfc category="exp" docName="feedprovider-00" ipr="none">
  <front>
    <title abbrev="FeedProvider">Atom and RSS Service Provider Extensions
    (Draft)</title>

    <author fullname="Martin Atkins" initials="M." surname="Atkins">
      <organization>Six Apart Ltd</organization>
    </author>

    <date />

    <abstract>
      <t>This document presents an extension that allows a service provider
      that publishes feeds to include information about itself in those
      feeds.</t>
    </abstract>

    <note title="Requirements Language">
      <t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
      "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
      document are to be interpreted as described in <xref
      target="RFC2119">RFC 2119</xref>.</t>
    </note>
  </front>

  <middle>
    <section title="Introduction">
      <t>This document presents an extension that allows a service provider
      that publishes feeds to include information about itself in those
      feeds.</t>
    </section>

    <section title="Notational Conventions">
      <t>The XML Namespaces URI [W3C.REC-xml-names-19990114] for the XML
      elements and attributes described in this specification is: <spanx
      style="verb">http://activitystrea.ms/service-provider</spanx>.</t>

      <t>In this document, the namespace prefix "service:" is used for the
      above Namespace URI. The namespace prefix "atom:" is used for the
      namespace URI <spanx style="verb">http://www.w3.org/2005/Atom</spanx>.
      The choices of namespace prefix are arbitrary and not
      semantically significant. RSS 2.0 elements, which are not in an XML
      namespace, are referred to simply as "RSS elements".</t>

      <t>This specification uses a shorthand form of terms from the XML
      Infoset [W3C.REC-xml-infoset-20040204]. The phrase "Information Item" is
      omitted when naming Element and Attribute Information Items. Therefore,
      when this specification uses the term "element," it is referring to an
      Element Information Item in Infoset terms. Likewise, when this
      specification uses the term "attribute," it is referring to an Attribute
      Information Item.</t>

      <t>This specification allows the use of IRIs [RFC3987]. Every URI
      [RFC3986] is also an IRI, so a URI may be used wherever an IRI is named.
      When an IRI that is not also a URI is given for dereferencing, it MUST
      be mapped to a URI using the steps in Section 3.1 of [RFC3987]. When an
      IRI is serving as an identifier, it MUST NOT be so mapped.</t>

      <t>This specification uses "the Atom specification" to refer to <xref
      target="RFC4287"></xref>.</t>
    </section>

    <section title="Service Provider Properties">
      <t>On the web today most users publish content of various types through
      one or more providers that specialize in publishing content. Examples of
      specific kinds of providers are photo hosting providers, blog hosting
      providers and video hosting providers, though there are many more.</t>

      <t>The atom:author element from the Atom specification allows a feed to
      describe the author of the content. The atom:generator element allows a
      feed to describe what software was used to generate it. Several child
      elements of atom:feed allow a feed to describe itself. However, the Atom
      specification provides no specific support for describing the service
      provider. While in some cases the "generator" value will describe this
      due to the software and the service having the same name, the ambiguity
      of this means that it cannot be reliably employed to obtain service
      provider information in practice.</t>

      <t>While it is anticipated that other uses of this information will
      emerge in future, the primary use-case addressed by the extensions
      described in the following sections is that of systems that publish a
      user's content aggregated from a number of services. In many cases such
      systems wish to include an icon representing the service and may also
      name and link to the service in the description of the content.</t>
    </section>

    <section title="The service:provider Element">
      <t>The <spanx style="verb">service:provider</spanx> element is a
      container for elements describing the service provider. Service
      providers MAY include a single <spanx style="verb">service:provider</spanx>
      element as a child of the <spanx style="verb">atom:feed</spanx> element.
      Content re-publishing services SHOULD include the <spanx style="verb">service:provider</spanx>
      element from the source feed in the atom:source element of any entries
      they republish, where such an element was present in the source
      feed.</t>

      <t>If a content re-publishing service can determine the information
      required for the <spanx style="verb">service:provider</spanx> element
      from another source not considered by this specification, it MAY
      synthesize a suitable <spanx style="verb">service:provider</spanx>
      element and include it in atom:source.</t>

      <t>The <spanx style="verb">service:provider</spanx> element MAY also be
      used as a child of an RSS <spanx style="verb">channel</spanx> element,
      where it has the same content model, meaning and processing expectations
      as when it appears in an <spanx style="verb">atom:feed</spanx> element.
      When used in an RSS channel, the child elements of <spanx style="verb">service:provider</spanx>
      are still Atom elements as described in the following sections, and must
      be declared to be in the appropriate namespace.</t>

      <t>This element is intended only for use in branded service provider
      scenarios. It MUST NOT be used to describe the software used to generate
      the feed unless that software has the same name, URL and icon as the
      branded service provider. It also MUST NOT be used in feeds that are
      "self-hosted" by their author. If the content is not hosted by a branded
      hosted provider the <spanx style="verb">service:provider</spanx> element
      MUST NOT be present.</t>

      <section title="The atom:name Element">
        <t>When used as a child of a <spanx style="verb">service:provider</spanx>
        element, the <spanx style="verb">atom:name</spanx> element contains
        the name of the service provider. When used in this way, the name
        element MUST NOT include a type attribute, and must therefore contain
        only text content as described by section 3.1.1.1 of the Atom
        specification.</t>

        <t>A <spanx style="verb">service:provider</spanx> Element MUST contain
        exactly one <spanx style="verb">atom:name</spanx> element.</t>

        <t>The value of this element SHOULD be the brand name of the
        publishing service as would be familiar to end-users of the
        service.</t>
      </section>

      <section title="The atom:icon Element">
        <t>When used as a child of a <spanx style="verb">service:provider</spanx>
        element, the <spanx style="verb">atom:icon</spanx> element contains an
        IRI reference that refers to an image that provides iconic visual
        identification for the service provider. Its content model is as
        defined in section 4.2.5 of the Atom specification.</t>

        <t>The icon referenced by this element SHOULD be 16 pixels in both
        dimensions and SHOULD have the media type image/png, image/gif or
        image/jpeg. The icon SHOULD be an icon form of the logo of the
        publishing service as would be familiar to end-users of the service.
        In most cases, this icon SHOULD be the same icon as used as the
        shortcut icon or "favicon" for the publishing service.</t>

        <t>A <spanx style="verb">service:provider</spanx> Element MUST contain
        zero or one <spanx style="verb">atom:icon</spanx> elements. If a
        processor encounters a feed with more than one provider icon, it MUST
        process only the first such child element of <spanx style="verb">service:provider</spanx>
        in document order and ignore all other sibling atom:icon elements.</t>

        <t>As required by the Atom specification, this element MUST
        NOT contain a relative URL.</t>
      </section>

      <section title="The atom:uri Element">
        <t>When used as a child of a <spanx style="verb">service:provider</spanx>
        element, the <spanx style="verb">atom:uri</spanx> element contains an
        IRI reference that refers to the "home page" of the service provider
        site.</t>

        <t>The page referenced by this element SHOULD be the entry point of
        the service as would be familiar to end-users of the service.</t>

        <t>A <spanx style="verb">service:provider</spanx> Element MUST contain
        zero or one <spanx style="verb">atom:uri</spanx> elements.</t>

        <t>As required by the Atom specification, this element MUST
        NOT contain a relative URL.</t>
      </section>
    </section>

    <section title="Security Considerations">
      <t>As this specification defines an extension to the Atom Syndication
      Format, it is subject to the same security considerations defined in
      <xref target="RFC4287"></xref>.</t>

      <t>The information provided in the elements described in this
      specification is intended only to be advisory, and should not be
      considered to be or presented to the user as authoritative metadata.</t>

      <t>[TODO: Write some more here.]</t>
    </section>

    <section title="IANA Considerations">
      <t>None.</t>
    </section>
  </middle>

  <back>
    <references title="Normative References">
      <reference anchor="RFC4287">
        <front>
          <title>The Atom Syndication Format</title>

          <author>
            <organization></organization>
          </author>

          <date />
        </front>
      </reference>

      <reference anchor="RFC2119">
        <front>
          <title>RFC 2119</title>

          <author>
            <organization></organization>
          </author>

          <date />
        </front>
      </reference>

      <reference anchor="RFC3987">
        <front>
          <title>Internationalized Resource Identifiers (IRIs)</title>

          <author>
            <organization></organization>
          </author>

          <date />
        </front>
      </reference>
    </references>

    <section title="Acknowledgements">
      <t>...</t>
    </section>

    <section title="Examples">
      <t>This appendix is non-normative.</t>

      <section anchor="activityentryexample" title="Feed Example">
        <figure>
          <preamble>A feed with service provider annotations.</preamble>

          <artwork><![CDATA[<feed xmlns="http://www.w3.org/2005/Atom"
      xmlns:service="http://activitystrea.ms/service-provider">
   <id>tag:photopanic.example.com,2008:activity01</id>
   <title>Geraldine's Photos at PhotoPanic</title>
   <generator>UberPhotoHostingSystem</generator>
   <updated>2008-11-02T15:29:00Z</updated>
   <link rel="alternate" type="text/html"
         href="/geraldine/activities" />
   <author>
      <name>Geraldine</name>
   </author>
   <service:provider>
      <name>PhotoPanic</name>
      <icon>http://photopanic.example.com/favicon.png</icon>
      <uri>http://photopanic.example.com/</uri>
   </service:provider>
</entry>]]></artwork>

          <postamble>This example shows a feed provided by a ficticious
          hosting provider called PhotoPanic, indicating its name, icon URL
          and home page URL. This example also includes an <spanx
          style="verb">atom:generator</spanx> element describing the
          ficticious software that powers PhotoPanic, and an <spanx
          style="verb">atom:author</spanx> element describing a ficticious
          user of PhotoPanic.</postamble>
        </figure>
      </section>
    </section>
  </back>
</rfc>