One document matched: draft-snell-atompub-tombstones-05.xml

<?xml version="1.0"?>

<!DOCTYPE rfc SYSTEM "rfc2629.dtd" [
    <!ENTITY rfc2119 PUBLIC '' 
      'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml'>
    <!ENTITY rfc4287 PUBLIC '' 
      'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4287.xml'>
    <!ENTITY rfc3339 PUBLIC '' 
      'http://xml.resource.org/public/rfc/bibxml/reference.RFC.3339.xml'>  
    <!ENTITY xmlnames PUBLIC ''
      'http://xml.resource.org/public/rfc/bibxml4/reference.W3C.REC-xml-names-19990114.xml'>
]>

<rfc category="exp" ipr="full3978" updates="4287" docName="draft-snell-atompub-tombstones-05.txt">
<?rfc toc="yes" ?>
<?rfc symrefs="yes" ?>
<?rfc sortrefs="yes"?>
<?rfc strict="yes" ?>
<?rfc toc="yes"?>
<?rfc compact="yes"?>

<?rfc strict="yes" ?>
<?rfc toc="yes"?>
<?rfc compact="yes"?>
<front>
<title abbrev="Atom deleted-entry">The Atom "deleted-entry" Element</title>
<author initials="J.M." surname="Snell" fullname="James M Snell">
<organization></organization>
<address>
<postal>
<street></street>
<city></city> <region></region> <code></code>
<country></country>
</postal>
<phone></phone>
<email>jasnell@gmail.com</email>
<uri>http://snellspace.com</uri>
</address>
</author>
<date month="April" year="2008" />
<area>General</area>
<keyword>I-D</keyword>
<keyword>Internet-Draft</keyword>
<keyword>XML</keyword>
<keyword>Extensible Markup Language</keyword>
<keyword>Atom</keyword>
<keyword>RSS</keyword>
<keyword>Syndication</keyword>
<abstract><t>This specification adds mechanisms to the Atom Syndication Format 
which Atom Feed publishers can use to explicitly identify Atom entries that have 
been removed from an Atom feed.</t></abstract>
</front>
<middle>
<section title="Introduction">

<t>This specification adds a new element to the Atom Syndication Format 
<xref target="RFC4287" /> that can be used to explicitly indicate that
specific entries have been removed from a feed.</t>

</section>

<section title="Notational Conventions">

<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 BCP 14, <xref target="RFC2119" /></t>

<t>This specification uses XML Namespaces <xref target="W3C.REC-xml-names-19990114"/>
to uniquely identify XML element names.  It uses the following namespace prefix 
for the indicated namespace URI;</t>

<figure><artwork><![CDATA[
 "at": "http://purl.org/atompub/tombstones/1.0"
]]></artwork></figure>

</section>

<section title="The at:deleted-entry element">

<t>The at:deleted-entry element MAY appear as a child of atom:feed to represent an
Atom Entry that has been removed from a feed.</t>

<figure><artwork><![CDATA[
  deletedEntry = element at:deleted-entry {
    atomCommonAttributes,
    attribute ref { atomUri },
    attribute when { atomDateConstruct },
    ( element at:by { atomPersonConstruct}?,
    & element at:comment {atomTextConstruct}?,
    & extensionElement* )
  }
]]></artwork></figure>

<t>The at:deleted-entry element MUST contain a ref attribute whose value 
specifies the value of the atom:id of the entry that has been removed.</t>

<t>The at:deleted-entry element MUST contain a when attribute whose value is an 
<xref target="RFC3339"/> "date-time" specifying the instant the entry was removed from the feed.
An uppercase "T" character MUST be used to separate date and time, and an uppercase 
"Z" character MUST be present in the absence of a numeric time zone offset</t>

<t>The at:deleted-entry element MAY contain one at:by element used to identify the
entity that removed the entry from the feed. The at:by element is an Atom Person
Construct as defined by Section 3.2 of <xref target="RFC4287" />.</t>

<t>The at:deleted-entry element MAY contain one at:comment element whose value 
provides additional, language-sensitive information about the deletion operation.  
The atom:comment element is an Atom Text Construct as defined by Section 3.1 of 
<xref target="RFC4287" />.</t>

<t>An Atom feed MAY contain any number of at:deleted-entry elements, but 
MUST NOT contain more than one with the same combination of ref and when attribute values.</t>

<figure><artwork><![CDATA[
  <feed xmlns="http://www.w3.org/2005/Atom"
        xmlns:at="http://purl.org/atompub/tombstones/1.0">
     ...
     <!-- Minimal deleted-entry -->
     <at:deleted-entry 
       ref="tag:example.org,2005:/entries/1" 
       when="2005-11-29T12:11:12Z"/>
     
     <!-- Extended deleted-entry -->
     <at:deleted-entry
       ref="tag:example.org,2005:/entries/2"
       when="2005-11-29T12:11:12Z">
       <at:by>
         <name>John Doe</name>
         <email>jdoe@example.org</email>
       </at:by>
       <at:comment>Removed comment spam</at:comment>
     </at:deleted-entry>
     ...
  </feed>
]]></artwork></figure>

<t>An Atom feed MAY contain atom:entry elements and at:deleted-entry elements 
sharing the same atom:id value.  Atom processors SHOULD ignore any at:deleted-entry 
elements sharing an atom:id value with an atom:entry whose atom:updated element 
specifies a date and time more recent than the at:deleted-entry element's when 
value.</t>

<t>Elements and attributes from other XML vocabularies MAY be used within an
at:deleted-entry element following the same model defined by Section 6 of <xref target="RFC4287" />.  
Processors encountering such markup MUST NOT stop processing or signal an error. 
It might be the case that the Processor is able to process the foreign markup 
correctly and does so.  When unknown markup is encountered as a child of 
at:deleted-entry, Processors MAY bypass the markup and any textual content and 
MUST NOT change their behavior as a result of the markup's presence.</t> 

</section>

<section title="Security Considerations">
  <t>As specified in <xref target="RFC4287"/>, Atom processors should be
  aware of the potential for spoofing attacks where an attacker publishes
  atom:entry or atom:deleted-entry elements using the same atom:id values as 
  entries from other Atom feeds.  An attacker may attempt to trick an application 
  into believing that a given entry has either been removed from or added to a feed.  
  To mitigate this issue, Atom processors are advised to ignore atom:deleted-entry 
  elements referencing entries that have not previously appeared within the 
  containing Feed document and should take steps to verify the origin of the
  Atom feed before considering the entries to be removed.</t>
</section>

<section title="IANA Considerations">
  
<t>No IANA actions are required by this document.</t>
  
</section>

<section title="Acknowledgements">
<t>The author gratefully acknowledges the feedback from the members of the 
Atom Publishing Format and Protocol working group during the development of 
this specification.</t>
</section>

</middle>

<back>
<references title="Normative References">
  &rfc2119;
  &rfc3339;
  &rfc4287;
  &xmlnames;
</references>
</back>
</rfc>