YAML Media Type
draft-ietf-httpapi-yaml-mediatypes-10

Received changes through RFC Editor sync (changed state to RFC, created became rfc relationship between draft-ietf-httpapi-yaml-mediatypes and RFC 9512, changed IESG state to RFC Published)

[Ballot comment]
# GEN AD review of draft-ietf-httpapi-yaml-mediatypes-06

CC @larseggert

Thanks to Elwyn Davies for the General Area Review Team (Gen-ART) review
(https://mailarchive.ietf.org/arch/msg/gen-art/o9UaFCXheaEmcZM-2Vw9RWuFI8Q).

## Comments

### Boilerplate

Document has Informational status, but uses the RFC2119 keywords "SHOULD",
"MAY", and "SHOULD NOT". Given how they are used, that may not be necessary?

### Inclusive language

Found terminology that should be reviewed for inclusivity; see
https://www.rfc-editor.org/part2/#inclusive_language for background and more
guidance:

* Term `native`; alternatives might be `built-in`, `fundamental`, `ingrained`,
  `intrinsic`, `original`

## Nits

All comments below are about very minor potential issues that you may choose to
address in some way - or ignore - as you see fit. Some were flagged by
automated tools (via https://github.com/larseggert/ietf-reviewtool), so there
will likely be some false positives. There is no need to let me know what you
did with these suggestions.

### Grammar/style

#### Section 3.4, paragraph 7
```
lues not supported in JSON in a multi- document YAML stream 3.5. Fragment ide
                                ^^^^^^^^^^^^^^^
```
This word seems to be formatted incorrectly. Consider fixing the spacing or
removing the hyphen completely.

#### Section 3.5, paragraph 4
```
o improper behaviors (such as the "billion laughs" or "Exponential Entity Exp
                                  ^^^^^^^
```
Use "a billion", or use a number before "billion".

#### "A.1.", paragraph 1
```
has some security implications too (eg. wrt on identifying parsers or treat
                                    ^^^
```
The abbreviation "e.g." (= for example) requires two periods.

## Notes

This review is in the ["IETF Comments" Markdown format][ICMF], You can use the
[`ietf-comments` tool][ICT] to automatically convert this review into
individual GitHub issues. Review generated by the [`ietf-reviewtool`][IRT].

[ICMF]: https://github.com/mnot/ietf-comments/blob/main/format.md
[ICT]: https://github.com/mnot/ietf-comments
[IRT]: https://github.com/larseggert/ietf-reviewtool

[Ballot comment]
Thank you to Shawn Emery for the SECDIR review.

** Section 1.2.1
In the example resource below, the URL file.yaml#*foo references the
  first alias node *foo pointing to the node with value scalar and not
  the one in the second document; whereas the URL file.yaml#*document_2
  references the root node of the second document { one: [a,
  sequence]}.

Are “file.yaml#*foo” and “file.yaml#*document_2” valid URLs?  There is no scheme or authority.

** Consider leaving the FAQ in the final RFC.  I believe it has archival value in explain design decisions.

** For the responsible AD evaluate:  The following are crucial normative references (especially [YAML]), however they are DOWNREFs not called out in IETF Last Call.

[YAML]    Oren Ben-Kiki, Clark Evans, Ingy dot Net, Tina Müller,
            Pantelis Antoniou, Eemeli Aro, and Thomas Smith, "YAML
            Ain't Markup Language Version 1.2", 1 October 2021,
            .
[OAS]    Darrel Miller, Jeremy Whitlock, Marsh Gardiner, Mike
            Ralphson, Ron Ratovsky, and Uri Sarid, "OpenAPI
            Specification 3.0.0", 26 July 2017.

[Ballot comment]
# Internet AD comments for draft-ietf-httpapi-yaml-mediatypes-06
CC @ekline

* comment syntax:
  - https://github.com/mnot/ietf-comments/blob/main/format.md

* "Handling Ballot Positions":
  - https://ietf.org/about/groups/iesg/statements/handling-ballot-positions/

## Comments

### S4.1

* Even though the document is Informational, S1.1 introduces the RFC 2119 and
  RFC 8174 keywords (which I find helpful for expressing intent irrespective
  of the document's intended status).

  With that in mind, I think this could be capitalised:

  "Code execution in deserializers should be disabled by default" ->
  "Code execution in deserializers SHOULD be disabled by default"

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

The IANA Functions Operator has completed its review of draft-ietf-httpapi-yaml-mediatypes-04. If any part of this review is inaccurate, please let us know.

The IANA Functions Operator has a question about one of the actions requested in the IANA Considerations section of this document.

The IANA Functions Operator understands that, upon approval of this document, there are two actions which we must complete.

First, in the application namespace of the Media Type registry located at:

https://www.iana.org/assignments/media-types/

a single, new registration will be made as follows:

Name: yaml
Template: [ TBD-at-Registration ]
Reference: [ RFC-to-be ]

Second, in the Structured Syntax Suffixes registry located at:

https://www.iana.org/assignments/media-type-structured-suffix/

a single, new registration will be made as follows:

Name:
+suffix: +yaml
References: [ RFC-to-be ]
Encoding Considerations:
Interoperability Considerations:
Security Considerations:
Contact:
Author/Change Controller:

IANA Question --> Can the authors provide all the required information for the entry in the Structured Syntax Suffixes registry?

As this document requests registrations in an Expert Review or Specification Required (see RFC 8126) registry, we will initiate the required Expert Review via a separate request. This review must be completed before the document's IANA state can be changed to "IANA OK."

The IANA Functions Operator understands that these are the only actions required to be completed upon approval of this document.

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Specialist

The following Last Call announcement was sent out (ends 2023-04-10):

From: The IESG
To: IETF-Announce
CC: darrel@tavis.ca, draft-ietf-httpapi-yaml-mediatypes@ietf.org, francesca.palombini@ericsson.com, httpapi-chairs@ietf.org, httpapi@ietf.org
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (YAML Media Type) to Informational RFC


The IESG has received a request from the Building Blocks for HTTP APIs WG
(httpapi) to consider the following document: - 'YAML Media Type'
  as Informational RFC

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2023-04-10. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

Abstract


  This document registers the application/yaml media type and the +yaml
  structured syntax suffix on the IANA Media Types registry.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-httpapi-yaml-mediatypes/



No IPR declarations have been submitted directly on this I-D.

# Document Shepherd Write-Up for Group Documents


## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

It has reached broad consensus.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been some concern raised over the +yaml suffix being registered in the document and how it might impact the ongoing work here https://github.com/ietf-wg-mediaman/suffixes with regard to fragment identifiers.  However, that issue was closed at IETF115 with the recognition that each registered suffix is explicit in saying what fragment identifier should be used. https://github.com/ietf-wg-mediaman/suffixes/issues/3

Due to compatibility challenges with the fragment identifier syntax defined for application/yaml and some of the candidate mediatypes that are looking to adopt the +yaml suffix, it was decided to defer the definition of the +yaml fragment identifier to any future mediatype registration that adopts the +yaml suffix.  This issue took some work to reach consensus, but did in the end https://github.com/ietf-wg-httpapi/mediatypes/issues/50.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize 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.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

  There are implementations that assume `application/yaml` is already a registered media type.  Seaching GitHub finds more than 43K files using the media type name https://cs.github.com/?scopeName=All+repos&scope=&q=%22application%2Fyaml%22 and more than 5K files using `+yaml` suffix. https://cs.github.com/?scopeName=All+repos&scope=&q=%2Byaml%22

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

Participants in the mediaman working group have been involved in reviewing this content.  Developers of yaml parsers have been involved.  Several members of the JSON Schema community have provided feedback as well as members of the OpenAPI community.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document contains a Media Type registration and a Structured Syntax Suffix registration in the IANA considerations section.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

It does not contain a YANG module.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

I validated the YAML examples with a linter. There are not other elements of structured content in the document that could be validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

This document is definitely needed, as can be seen by the large number of instances of it already being in use without official registration.  The document is clearly written and complete.  It is ready to be handed off to the area director.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?
   
The majority of the listed issues are not applicable to this document. However, the section on media types is relevant.  Submission to the ietf-types@ mailing list is planned.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

The document is requested as an Informational RFC.  It is a "stand-alone" registration only Informational RFC in accordance with guidance in RFC 6838.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes, all authors have been reminded of their IPR disclosure obligations. 

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

Yes, all authors have shown their willingness to be listed as authors. 

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

Nits:
- Outdated reference: draft-ietf-httpbis-semantics has been published as
    RFC 9110
- Code samples are not being surrounded by<CODE BEGINS>" and <CODE ENDS> lines.
- RFC5234 and RFC7405 is referenced as a normative reference but there does not appear to be any use of ABNF in the document.
- OAS 3.0.0 is referenced as a normative reference but it does not contain a link to https://spec.openapis.org/oas/v3.0.0
- The non-normative reference to I-D.ietf-jsonpath-base should be removed when the FAQ section is removed



15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

Other than the above mentioned nit related to RFC5234 and RFC7405, the references listed are in the appropriate sections.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

All normative references are freely available.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

No.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

No.

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The IANA considerations section requests that the media type registry be updated to include a new entry for application/yaml.  It also requests the addition of the Structured Syntax Suffix for +yaml.  These registrations are the primary purpose of the document.  The content in the IANA considerations section meets the requirements of RFC 8126.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

No new IANA registries are created.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://trac.ietf.org/trac/ops/wiki/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://trac.ietf.org/trac/iesg/wiki/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

# Document Shepherd Write-Up for Group Documents


## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

It has reached broad consensus.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been some concern raised over the +yaml suffix being registered in the document and how it might impact the ongoing work here https://github.com/ietf-wg-mediaman/suffixes with regard to fragment identifiers.  However, that issue was closed at IETF115 with the recognition that each registered suffix is explicit in saying what fragment identifier should be used. https://github.com/ietf-wg-mediaman/suffixes/issues/3

Due to compatibility challenges with the fragment identifier syntax defined for application/yaml and some of the candidate mediatypes that are looking to adopt the +yaml suffix, it was decided to defer the definition of the +yaml fragment identifier to any future mediatype registration that adopts the +yaml suffix.  This issue took some work to reach consensus, but did in the end https://github.com/ietf-wg-httpapi/mediatypes/issues/50.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize 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.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

  There are implementations that assume `application/yaml` is already a registered media type.  Seaching GitHub finds more than 43K files using the media type name https://cs.github.com/?scopeName=All+repos&scope=&q=%22application%2Fyaml%22 and more than 5K files using `+yaml` suffix. https://cs.github.com/?scopeName=All+repos&scope=&q=%2Byaml%22

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

Participants in the mediaman working group have been involved in reviewing this content.  Developers of yaml parsers have been involved.  Several members of the JSON Schema community have provided feedback as well as members of the OpenAPI community.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document contains a Media Type registration and a Structured Syntax Suffix registration in the IANA considerations section.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

It does not contain a YANG module.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

I validated the YAML examples with a linter. There are not other elements of structured content in the document that could be validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

This document is definitely needed, as can be seen by the large number of instances of it already being in use without official registration.  The document is clearly written and complete.  It is ready to be handed off to the area director.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?
   
The majority of the listed issues are not applicable to this document. However, the section on media types is relevant.  Submission to the ietf-types@ mailing list is planned.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

The document is requested as an Informational RFC.  It is a "stand-alone" registration only Informational RFC in accordance with guidance in RFC 6838.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes, all authors have been reminded of their IPR disclosure obligations. 

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

Yes, all authors have shown their willingness to be listed as authors. 

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

Nits:
- Outdated reference: draft-ietf-httpbis-semantics has been published as
    RFC 9110
- Code samples are not being surrounded by<CODE BEGINS>" and <CODE ENDS> lines.
- RFC5234 and RFC7405 is referenced as a normative reference but there does not appear to be any use of ABNF in the document.
- OAS 3.0.0 is referenced as a normative reference but it does not contain a link to https://spec.openapis.org/oas/v3.0.0
- The non-normative reference to I-D.ietf-jsonpath-base should be removed when the FAQ section is removed



15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

Other than the above mentioned nit related to RFC5234 and RFC7405, the references listed are in the appropriate sections.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

All normative references are freely available.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

No.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

No.

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The IANA considerations section requests that the media type registry be updated to include a new entry for application/yaml.  It also requests the addition of the Structured Syntax Suffix for +yaml.  These registrations are the primary purpose of the document.  The content in the IANA considerations section meets the requirements of RFC 8126.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

No new IANA registries are created.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://trac.ietf.org/trac/ops/wiki/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://trac.ietf.org/trac/iesg/wiki/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

This starts a two-week working group last call (WGLC) for the YAML Mediatypes draft.

If you have issues or other opposition to this document being forwarded along, please respond within two weeks.