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Shepherd writeup

As required by RFC 4858, this is the current template for the Document 
Shepherd Write-Up.

Changes are expected over time. This version is dated 24 February 2012.

(1) What type of RFC is being requested (BCP, Proposed Standard,
Internet Standard, Informational, Experimental, or Historic)?  Why
is this the proper type of RFC?  Is this type of RFC indicated in the
title page header?

   Proposed Standard, which is indicated in the header. This 
   draft updates RFC 5621, which is Proposed Standard, and 
   registers the Content-ID header field, which requires 
   standards action.

(2) The IESG approval announcement includes a Document Announcement
Write-Up. Please provide such a Document Announcement Write-Up. Recent
examples can be found in the "Action" announcements for approved
documents. The approval announcement contains the following sections:

Technical Summary

   This document specifies the Content-ID header field for 
   usage in the Session Initiation Protocol (SIP) to identify 
   a complete message-body of a SIP message. The document also 
   updates RFC 5621, to enable a Content-ID URL to reference 
   a complete message-body and metadata provided by some  
   additional SIP header fields. 

Working Group Summary

   Discussions about the Content-ID header field started in the 
   ECRIT working group when the group identified cases where a 
   request with a single message body also needs to include a 
   Content-ID header field in the SIP message header to refer to 
   the MIME entity, but the Content-ID header field was not actually 
   a SIP header field, surprising some working group members. The 
   authors brought the issue to the SIPCORE working group. There 
   was consensus that this was an oversight in SIP. There was a 
   discussion about perhaps adding all the Content-* MIME header 
   fields as SIP header fields for completeness (SIP already has 
   extended the some of the MIME header fields), but the working 
   group decided to focus only on Content-ID since there wasn't a 
   clear need for some of the others like Content-Transfer-Encoding. 

Document Quality

   This short document received detailed review from a handful  
   of working group participants. The authors incorporated received

   Although the Document Shepherd is not aware of implementations,
   the Content-ID header field will be useful when transporting
   data for location conveyance and emergency calls. There may be 
   implementations of Content-ID as a SIP header field since 
   RFC 5368 shows Content-ID as a SIP header field in its examples.


  Jean Mahoney is the document shepherd. Ben Campbell is 
  the responsible area director. 

(3) Briefly describe the review of this document that was performed by
the Document Shepherd.  If this version of the document is not ready
for publication, please explain why the document is being forwarded to
the IESG.

  The shepherd thoroughly reviewed the last versions of the draft.
  The document is ready to be forwarded to the IESG.  

(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed?


(5) Do portions of the document need review from a particular or from
broader perspective, e.g., security, operational complexity, AAA, DNS,
DHCP, XML, or internationalization? If so, describe the review that
took place.

   The document requires no specialized expertise beyond that 
   possessed by regular participants in the SIPCORE working group.

(6) Describe any specific concerns or issues that the Document Shepherd
has with this document that the Responsible Area Director and/or the
IESG should be aware of? For example, perhaps he or she is uncomfortable
with certain parts of the document, or has concerns whether there really
is a need for it. In any event, if the WG has discussed those issues and
has indicated that it still wishes to advance the document, detail those
concerns here.

   No concerns. 

(7) Has each author confirmed that any and all appropriate IPR
disclosures required for full conformance with the provisions of BCP 78
and BCP 79 have already been filed. If not, explain why.

   Each author has confirmed conformance with BCPs 78 and 79.

(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR

   No disclosure has been filed.

(9) How solid is the WG consensus behind this document? Does it 
represent the strong concurrence of a few individuals, with others
being silent, or does the WG as a whole understand and agree with it?   

   Most of the regular WG participants reviewed the document,
   (although SIPCORE is not large), and there were no dissent.
   There was consensus that a lack of a Content-ID header field
   was an oversight in SIP. 

(10) Has anyone threatened an appeal or otherwise indicated extreme 
discontent? If so, please summarise the areas of conflict in separate
email messages to the Responsible Area Director. (It should be in a
separate email because this questionnaire is publicly available.) 


(11) Identify any ID nits the Document Shepherd has found in this
document. (See and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
   idnits 2.14.01 was run, and no issues were found.
   The Shepherd checked the draft against
   No issues were found with the draft.

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.

   No formal review requirements are triggered by this document, 
   aside from any required by IANA process.

(13) Have all references within this document been identified as
either normative or informative?


(14) Are there normative references to documents that are not ready for
advancement or are otherwise in an unclear state? If such normative
references exist, what is the plan for their completion?


(15) Are there downward normative references references (see RFC 3967)?
If so, list these downward references to support the Area Director in 
the Last Call procedure. 


(16) Will publication of this document change the status of any
existing RFCs? Are those RFCs listed on the title page header, listed
in the abstract, and discussed in the introduction? If the RFCs are not
listed in the Abstract and Introduction, explain why, and point to the
part of the document where the relationship of this document to the
other RFCs is discussed. If this information is not in the document,
explain why the WG considers it unnecessary.

   This document updates RFC 5621, and this is captured in
   the header, abstract and introduction. 

(17) Describe the Document Shepherd's review of the IANA considerations
section, especially with regard to its consistency with the body of the
document. Confirm that all protocol extensions that the document makes
are associated with the appropriate reservations in IANA registries.
Confirm that any referenced IANA registries have been clearly
identified. Confirm that newly created IANA registries include a
detailed specification of the initial contents for the registry, that
allocations procedures for future registrations are defined, and a
reasonable name for the new registry has been suggested (see RFC 5226).

   The IANA Considerations section clearly identifies the 
   "Header Fields" sub-registry within the "Session Initiation 
   Protocols" registry, and provides the values for a new row 
   in that sub-registry. 

(18) List any new IANA registries that require Expert Review for future
allocations. Provide any public guidance that the IESG would find
useful in selecting the IANA Experts for these new registries.

   This document adds a new entry to an existing IANA registry. 
   The registration procedure is Standards Action, which this 
   document is following. 

(19) Describe reviews and automated checks performed by the Document
Shepherd to validate sections of the document written in a formal
language, such as XML code, BNF rules, MIB definitions, etc.

   Chris Newman's ABNF Validator, available at, was run. 
   The tool complained about undefined rules. However,
   those rules are defined in RFC 5322 and RFC 3261, and
   the document references those rules.