As required by RFC 4858, this is the current template for the Document
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?
Standards-Track -- this specification defines a set of media types to
be used in interchange.
(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:
The Sensor Measurement Lists (SenML) media type and data model can
be used to send collections of resources, such as batches of sensor
data or configuration parameters. The existing media types
(defined in RFC 8428) are useful for the traditional operations
GET, PUT, POST. The CoAP iPATCH, PATCH, and FETCH methods enable
accessing and updating parts of a resource or multiple resources
with one request. For using these methods to access and operate on
resources represented with the SenML data model, the present
document defines variants of the SenML media types, for JSON and
CBOR representations only.
Working Group Summary
Most of the discussion in the WG (up to and including the last
call) centered around whether the existing media types should be
shoe-horned into use with the new methods or new media types were
needed. In the end, having a simple way to apply a slight variant
won out over having a more complex way to apply something that is
nominally, but not really SenML. Christian Amsüss was kind enough
to summarize his view of the result of the discussion into a Wiki
which will be useful in avoiding revisiting the issues when they
inevitably come up for the next media type.
Are there existing implementations of the protocol? Have a
significant number of vendors indicated their plan to
implement the specification? Are there any reviewers that
merit special mention as having done a thorough review,
e.g., one that resulted in important changes or a
conclusion that the document had no substantive issues? If
there was a MIB Doctor, Media Type or other expert review,
what was its course (briefly)? In the case of a Media Type
review, on what date was the request posted?
Implementations of this media type will often be done in the context
of the OMA LWM2M specification, which is set to pick up the new media
types in future versions (1.1.1 hints: "The media types,
application/senml-etch+json and application/senml-etch+cbor, will
remove the requirement for context aware parsing."). None of the
implementations this shepherd is aware of is public yet: one existing
implementation, and one implementation that is in the product plan of
A media type review has been requested 2019-07-12 in
Who is the Document Shepherd? Who is the Responsible Area
Shepherd: Carsten Bormann <firstname.lastname@example.org> (CoRE Co-chair)
Responsible AD: Alexey Melnikov
(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
This document was reviewed by the Shepherd in a "Chair's Review", a
process step we like to exercise in the CoRE WG before issuing a WGLC.
The document is ready.
(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed?
This is a simple specification. The WGLC ended without any further
reviews at all, maybe because the document is so obvious. After some
nudging, re-reviews came from previous commenters (Christian Amsüss)
as well as a new review from Klaus Hartke, whose comments were then
addressed in -04.
(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
(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
(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.
Yes; both authors indicated to the Shepherd that they are not
personally aware of any IPR claims applying to this specification.
(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
(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?
SenML is a bit of a specialty topic in the WG. Those interested in
SenML, understand and agree.
(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 https://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.
A media type review has been requested 2019-07-12 in
(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?
All normative references are Proposed Standard RFCs (plus BCP 14).
(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.
(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 8126).
No new registries. Registration of two new media types and the
attendant CoRE Content-Format numbers.
(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.
No new registries.
(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.
No FDT were in use.
The JSON examples in the specification have been checked by the
Shepherd; a superfluous comma in the second JSON example (FETCH
response) in Section 3.1 needs to be removed before advancing the