[core] [IANA #1264407] [Errata Verified] RFC7252 (4954)

[Sabrina Tanamal via RT <[e-mail]>]

Hi all, 

We've updated the column headings in the CoAP Content-Formats registry and listed this errata as an additional reference for the registry. Please see

https://www.iana.org/assignments/core-parameters

Best regards, 

Sabrina Tanamal
Lead IANA Services Specialist

On Wed Jan 18 09:11:50 2023, [e-mail] wrote:
> The following errata report has been verified for RFC7252,
>  "The Constrained Application Protocol (CoAP)".
> 
> --------------------------------------
> You may review the report below and at:
> https://www.rfc-editor.org/errata/eid4954
> 
> --------------------------------------
> Status: Verified
> Type: Editorial
> 
> Reported by: Klaus Hartke <[e-mail]>
> Date Reported: 2017-02-28
> Verified by: Francesca Palombini (IESG)
> 
> Section: 12.3
> 
> Original Text
> -------------
> CoAP does not include a separate way to convey content-encoding
> information with a request or response, and for that reason the
> content-encoding is also specified for each identifier (if any).  If
> multiple content-encodings will be used with a media type, then a
> separate Content-Format identifier for each is to be registered.
> Similarly, other parameters related to an Internet media type, such
> as level, can be defined for a CoAP Content-Format entry.
> 
> +--------------------------+----------+----+------------------------+
> | Media type               | Encoding | ID | Reference              |
> +--------------------------+----------+----+------------------------+
> 
> 
> Corrected Text
> --------------
> CoAP does not include a separate way to convey content-coding
> information with a request or response, and for that reason the
> content-coding is also specified for each identifier (if any).  If
> multiple content-codings will be used with a media type, then a
> separate Content-Format identifier for each is to be registered.
> Similarly, other parameters related to an Internet media type, such
> as level, can be defined for a CoAP Content-Format entry.
> 
> +--------------------------+----------------+----+------------------+
> | Content type             | Content coding | ID | Reference        |
> +--------------------------+----------------+----+------------------+
> 
> 
> Notes
> -----
> A CoAP Content-Format is the combination of an Internet Media Type
> with an HTTP Content Coding, as correctly explained in the first
> paragraphs of Section 12.3. However, the next paragraph (the original
> text above) incorrectly uses the term "content-encoding". The correct
> term is "content-coding", as shown in the corrected text.
> 
> Examples for _valid_ CoAP Content-Format registrations:
> 
> - media type "text/plain; charset=iso-8859-1" with content-coding
> "deflate"
> 
> - media type "image/png" with content-coding "" (no content-coding)
> 
> - media type "image/png" with content-coding "identity" (same as
> previous, no content-coding)
> 
> - media type "application/example+xml" with content-coding "exi"
> 
> Examples for _invalid_ CoAP Content-Format registrations:
> 
> - media type "application/coap-group+json" with content-coding "UTF-8"
> (UTF-8 is a character encoding, not a content-coding; should be media
> type "application/coap-group+json; charset=utf-8" with content-coding
> "identity")
> 
> - media type "audio/opus" with content-coding "identity" ("audio/opus"
> has a required parameter "rate"; should be media type "audio/opus;
> rate=48000" with content-coding "identity")
> 
> - media type "application/example+xml" with content-coding "identity,
> exi" (too many content-codings; should be media type
> "application/example+xml" with content-coding "identity" and,
> separately, media type "application/example+xml" with content-coding
> "exi")
> 
> - media type "application/example+exi" with content-coding "identity"
> ("+exi" is not a registered structured syntax suffix at the time of
> writing of this erratum)
> 
> - media type "video/ogg" with content-coding "exi" (EXI is a content-
> coding for XML information)
> 
> --------------------------------------
> RFC7252 (draft-ietf-core-coap-18)
> --------------------------------------
> Title               : The Constrained Application Protocol (CoAP)
> Publication Date    : June 2014
> Author(s)           : Z. Shelby, K. Hartke, C. Bormann
> Category            : PROPOSED STANDARD
> Source              : Constrained RESTful Environments APP
> Area                : Applications
> Stream              : IETF
> Verifying Party     : IESG