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RFC 9720
Obsoletes RFC 7990
Updates RFC 9280
Editorial Stream P. Hoffman
Request for Comments: 9720 ICANN
Obsoletes: 7990 H. Flanagan
Updates: 9280 Spherical Cow Consulting
Category: Informational January 2025
ISSN: 2070-1721
RFC Formats and Versions
Abstract
In order to improve the readability of RFCs while supporting their
archivability, the definitive version of the RFC Series transitioned
from plain-text ASCII to XML using the RFCXML vocabulary; different
publication versions are rendered from that base document. This
document describes how RFCs are published.
This document obsoletes RFC 7990. This document also updates the
stability policy in RFC 9280.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the RFC Series Policy Definition
Process. It represents the consensus of the RFC Series Working Group
approved by the RFC Series Approval Board. Such documents are not
candidates for any level of Internet Standard; see Section 2 of RFC
7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9720.
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document.
Table of Contents
1. Introduction
1.1. Changes to RFC 7990
1.2. Changes to RFC 9280
1.3. Key Changes from the Earlier RFC Process
2. Definitive Version of an RFC
2.1. Updating the Definitive Version of an RFC
2.2. Expected Updates to RFCXML
3. Publication Versions
4. Archived Documents
5. IANA Considerations
6. Security Considerations
7. References
7.1. Normative References
7.2. Informative References
Acknowledgments
Authors' Addresses
1. Introduction
"RFC Series Format Requirements and Future Development" [RFC6949]
discussed the need to improve the display of items such as author
names and artwork in RFCs as well as the need to improve the ability
of RFCs to be displayed properly on various devices. Based on
discussions with communities of interest, such as the IETF, the RFC
Series Editor decided to explore a change to the format of the
Series. [RFC7990] was the culmination of that exploration.
This document is concerned with the production of RFCs, focusing on
the published documents. It does not address any changes to the
processes each stream uses to develop and review their submissions
(specifically, how Internet-Drafts are developed). While I-Ds have a
similar set of issues and concerns, directly addressing those issues
for I-Ds should be discussed within each document stream.
The details described in this document are expected to continue to
change over time as the community and the RFC Production Center (RPC)
gain further experience implementing the policies described here.
Implementors of these components are advised to avoid assuming that
all such changes will be backwards compatible.
1.1. Changes to RFC 7990
[RFC7990] defined a framework for how RFCs would be published,
including new "publication formats" and a new "canonical format". It
talked about "the XML file" as if there would only be one XML file
for an RFC because that was the expectation at the time [RFC7990] was
published. It also talked about "publication formats" as the
versions of HTML, plain text, and PDF derived from the "canonical
format".
After extensive experience with publishing RFCs in the RFCXML format
[RFC7991], it has been decided that an RFC's XML file can be updated
for narrowly limited purposes. This document changes [RFC7990] in
significant ways:
* It defines four terms that replace the use of the term "canonical"
and clarifies "format":
- The "definitive format", which is RFCXML
- The "definitive version", which is a published RFC in the
definitive format
- A "publication format", which is currently one of HTML, plain
text, and PDF
- A "publication version", which is a published RFC in one of the
publication formats
* It defines a policy governing how the RFCXML format changes.
* It defines a policy for when the definitive version of an RFC can
be updated and older definitive versions archived.
* It defines a policy for when the publication versions of an RFC
can be updated and older publication versions archived.
When using the new terminology, it is important to note that
[RFC7990] used the term "canonical format" to mean two very different
things. Quoting from RFC 7990:
| Canonical format: the authorized, recognized, accepted, and
| archived version of the document
and
| At the highest level, the changes being made to the RFC format
| involve breaking away from solely ASCII plain text and moving to a
| canonical format that includes all the information required for
| rendering a document into a wide variety of publication formats.
This document uses two terms, "definitive version" and "definitive
format", for the earlier term "canonical format".
This document also makes the following terminology changes:
* It changes the phrase "xml2rfc version 3" to "RFCXML".
* It changes the name of the body that publishes RFCs from "RFC
Editor" to "RFC Production Center" (RPC).
Historical text from [RFC7990], such as Section 2 ("Problem
Statement"), Section 4 ("Overview of the Decision-Making Process"),
and Section 10 ("Transition Plan"), was purposely omitted from this
document. Text from [RFC7990] that repeated what was in other RFCs,
particularly Section 8 ("Figures and Artwork") and Section 9
("Content and Page Layout"), was also removed.
1.2. Changes to RFC 9280
Section 7.6 of [RFC9280] says:
| Once published, RFC Series documents are not changed.
This document replaces that sentence with:
| Once published, RFCs may be reissued, but the semantic content of
| publication versions shall be preserved to the greatest extent
| possible.
This document also adds a new policy to Section 7 of [RFC9280]:
| 7.8. Consistency
|
| RFCs are copyedited, formatted, and then published. They may
| be reissued to maintain a consistent presentation.
Sections 2.1 and 3 in this document are based on this policy in
[RFC9280].
1.3. Key Changes from the Earlier RFC Process
The first RFC to be published following the guidance of the group of
RFCs described in [RFC7990] was [RFC8651], published in October 2019.
In the time since then, all published RFCs have followed the general
plan from [RFC7990].
At the highest level, the changes that [RFC7990] made to the RFC
format involved breaking away from solely ASCII [RFC20] plain text
and moving to a definitive format that includes all the information
required for rendering a document into a wide variety of publication
formats. The RPC became responsible for more than just the plain-
text file and a PDF rendering that was created from the plain text at
the time of publication; the RPC now creates the definitive version
and three publication versions of the RFC in order to meet the
diverse requirements of the community.
The final RFCXML file produced by the RPC is the definitive version
for RFCs; it holds all the information intended for an RFC.
Additional publication versions (HTML, plain text, and PDF) are also
published by the RPC. The publication formats are fully specified in
other RFCs.
2. Definitive Version of an RFC
The definitive version produced by the RPC holds all the information
intended for an RFC. The RPC may change the definitive version of an
RFC over time (that is, change the XML file), as described in
Section 2.1. See [RFC7991] for the original complete description of
RFCXML.
The XML may contain SVG line art, as originally described in
[RFC7996]. That SVG will also appear in the HTML publication
version. The XML may contain non-ASCII characters, as originally
described in [RFC7997]. These characters will appear in all the
publication versions.
The definitive version must contain all information necessary to
render the specified publication versions; any question about what
was intended in the publication will be answered from this file. It
is self-contained with all the semantic content known at publication
time. For instance, all features that reference externally defined
input are expanded. It does not contain src attributes for <artwork>
or <sourcecode> elements. It does not contain comments or processing
instructions.
2.1. Updating the Definitive Version of an RFC
RFCs may be reissued, as described in Section 1.2. Such changes must
preserve the semantics expressed in the original RFC. Reasons to
make such changes include updates to the RFCXML schema, errors
discovered in the XML, and changes to the tooling used to generate
the publication versions of the definitive version of the RFC. The
RPC will keep a public record of when it reissues any RFC and give a
short description of its reasoning for each change.
2.2. Expected Updates to RFCXML
It is anticipated that [RFC7991] will be updated. Updates to the
RFCXML specification that are applied to existing RFCs should
preserve the semantics expressed in the original RFC to the greatest
extent possible. The goal of limiting changes only to syntax is to
preserve the semantic meaning encoded in the published document.
This policy does not require that updates to RFCXML avoid all risk of
introducing semantic changes to existing RFCs. Instead, considering
the potential for semantic changes, taking steps to understand the
risk of a semantic change (either deliberate or inadvertent), and
limiting associated risks are the only requirements.
3. Publication Versions
The RPC is permitted but not required to reissue publication versions
of an RFC, as described in Section 1.2. In deciding whether to
update the publication versions of an RFC, the RPC will take into
account both the risk of semantic changes and consistency of the
Series.
XML format errors and better design choices have been discovered by
the community since the first RFCs were published using the RFCXML
format. When the XML in a definitive version changes, the
publication versions may change, even if this might not result in
observable differences. Similarly, as production tools change,
publication versions may be regenerated to ensure a consistent
presentation.
4. Archived Documents
The RPC will keep an archived set of all definitive versions of RFCs
as well as archived sets of the publication versions for an RFC that
were previously published. These archived sets must be available
using the same access methods as for current definitive and
publication versions. Every archived set shall record the date that
a definitive and/or publication version was created or reissued.
When the RPC archives definitive and publication versions, it does so
in a manner that allows them to be found by people who want the
historical (as compared to current) files.
This document does not specify how archives are maintained or how
archived documents might be located or identified. The methods for
storage and access will be determined by the RPC in consultation with
the technical community.
5. IANA Considerations
This document has no IANA actions.
6. Security Considerations
Allowing changes to the definitive version and publication versions
of RFCs introduces risks. A significant risk is that unintended
changes could occur in either the definitive version or publication
versions of an RFC as a result of an editing error. In addition,
unintended changes may be introduced into a publication version when
it is regenerated from the definitive version. This may result in
the corruption of a standard, practice, or critical piece of
information about a protocol, which may harm the reputation of the
RFC Series.
The RPC is expected to identify, track, and actively mitigate risks
introduced by this new policy.
7. References
7.1. Normative References
[RFC7991] Hoffman, P., "The "xml2rfc" Version 3 Vocabulary",
RFC 7991, DOI 10.17487/RFC7991, December 2016,
<https://www.rfc-editor.org/info/rfc7991>.
[RFC7996] Brownlee, N., "SVG Drawings for RFCs: SVG 1.2 RFC",
RFC 7996, DOI 10.17487/RFC7996, December 2016,
<https://www.rfc-editor.org/info/rfc7996>.
[RFC7997] Flanagan, H., Ed., "The Use of Non-ASCII Characters in
RFCs", RFC 7997, DOI 10.17487/RFC7997, December 2016,
<https://www.rfc-editor.org/info/rfc7997>.
[RFC9280] Saint-Andre, P., Ed., "RFC Editor Model (Version 3)",
RFC 9280, DOI 10.17487/RFC9280, June 2022,
<https://www.rfc-editor.org/info/rfc9280>.
7.2. Informative References
[RFC20] Cerf, V., "ASCII format for network interchange", STD 80,
RFC 20, DOI 10.17487/RFC20, October 1969,
<https://www.rfc-editor.org/info/rfc20>.
[RFC6949] Flanagan, H. and N. Brownlee, "RFC Series Format
Requirements and Future Development", RFC 6949,
DOI 10.17487/RFC6949, May 2013,
<https://www.rfc-editor.org/info/rfc6949>.
[RFC7990] Flanagan, H., "RFC Format Framework", RFC 7990,
DOI 10.17487/RFC7990, December 2016,
<https://www.rfc-editor.org/info/rfc7990>.
[RFC8651] Cheng, B., Wiggins, D., and L. Berger, Ed., "Dynamic Link
Exchange Protocol (DLEP) Control-Plane-Based Pause
Extension", RFC 8651, DOI 10.17487/RFC8651, October 2019,
<https://www.rfc-editor.org/info/rfc8651>.
Acknowledgments
Martin Thomson wrote a great deal of the significant text here as
part of draft-thomson-rswg-syntax-change-01.
This document has greatly benefited from the input of the RSWG. In
particular, Alexis Rossi, Brian Carpenter, Eliot Lear, Jay Daley,
Jean Mahoney, John Levine, and Pete Resnick provided significant
input on the early draft versions of this document.
Authors' Addresses
Paul Hoffman
ICANN
Email: paul.hoffman@icann.org
Heather Flanagan
Spherical Cow Consulting
Email: hlf@sphericalcowconsulting.com