Internet DRAFT - draft-rfc-format-flanagan
draft-rfc-format-flanagan
INTERNET-DRAFT H. Flanagan
Intended Status: Informational RFC Series Editor
N. Brownlee
Independent Submissions Editor
Expires: May 31, 2013 November 27, 2012
RFC Series Format Development
draft-rfc-format-flanagan-02
Abstract
This document describes the current requirements and requests for
enhancements for the format of the canonical version of RFCs. Terms
are defined to help clarify exactly which stages of document
production are under discussion for format changes. The requirements
described in this document will determine what changes will be made
to RFC format.
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as
Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
Copyright and License Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://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. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
2. History and Goals . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Issues driving change . . . . . . . . . . . . . . . . . . 5
2.1.1. Line art, aka ASCII art . . . . . . . . . . . . . . . 6
2.1.2. Character encoding . . . . . . . . . . . . . . . . . . 7
2.1.3. Pagination . . . . . . . . . . . . . . . . . . . . . . 8
2.1.4. Reflowable text . . . . . . . . . . . . . . . . . . . 8
2.1.5. Metadata and tagging . . . . . . . . . . . . . . . . . 8
2.2. Further considerations . . . . . . . . . . . . . . . . . . 9
2.2.1. Creation and use of RFC-specific tools . . . . . . . . 9
2.2.2. Markup Language . . . . . . . . . . . . . . . . . . . 10
2.3. RFC Editor goals . . . . . . . . . . . . . . . . . . . . . 10
3. Format requirements . . . . . . . . . . . . . . . . . . . . . 10
3.1. Original requirements to be retained . . . . . . . . . . . 10
3.2. Requirements to be added . . . . . . . . . . . . . . . . . 11
3.3. Requirements to be retired . . . . . . . . . . . . . . . . 12
4. Security Considerations . . . . . . . . . . . . . . . . . . . 12
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.1. Normative References . . . . . . . . . . . . . . . . . . . 13
6.2. Informative References . . . . . . . . . . . . . . . . . . 13
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
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1 Introduction
Over 40 years ago, the RFC Series began in an environment that
included handwritten RFCs, typewritten RFCs, RFCs produced on
mainframes, and more. This resulted in an understanding that however
they were published, a common format that could be read and revised
long in the future was required. US-ASCII was chosen as that format,
and since that time that format has proved to be persistent and
reliable across a large variety of devices, operating systems, and
editing tools. That stability has been a continuing strength of the
Series. However, as new technology such as small devices and
advances in display technology come in to common usage, there is a
growing desire to see the format of the RFC Series adapt to take
advantage of these different ways to communicate information.
Since the earliest days of the Series, authors and readers have
suggested enhancements to the format. However, no suggestion
developed clear consensus in the Internet technical community. As
always, some individuals see no need for change while others press
strongly for specific enhancements.
This document takes a look at the current requirements for RFCs as
described in RFC 2223 [RFC2223] and more recently in 2223bis
[2223bis]. It also reviews recent requests for enhancements as
understood from community discussion and various proposals for new
formats including HTML, XML, PDF and EPUB. The focus of this
document is on the Canonical format of RFCs, but some mention of
other phases in the RFC publication process and the document formats
associated with these phases is also included. Terms are defined to
help clarify exactly which stages of document production are under
discussion for format changes.
1.1 Terminology
[ASCII] = Coded Character Set -- 7-bit American Standard Code for
Information Interchange", ANSI X3.4-1986.
Submission format = the format submitted to the RFC Editor for
editorial revision and publication.
* might not be the same as the canonical format (though it would
make the workflow somewhat simpler for the RFC Editor if it
were);
* will be converted to another format for further processing and
publication if necessary
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* Currently: .txt (required), XML (optional), NROFF (optional)
Revisable format = the format that will provide the information for
conversion into an Publication format; it is used or created by the
RFC Editor
* Currently: XML (optional), NROFF (required)
Publication format = display and distribution format as it may be
read or printed after publication process has completed.
* Currently published by the RFC Editor: .txt, PDF, PDF that
contains figures (rare)
* Currently made available by other sites: HTML, PDF, others
Canonical format = the authorized, recognized, accepted, and archived
version of the document.
* Currently: .txt
Metadata = Information associated with a document so as to provide,
for example, definitions of its structure, or of elements within it
such as it topic or author.
2. History and Goals
Current RFC format rules as defined in [RFC2223] and clarified in
2223bis.
* The character codes are ASCII.
* Each page must be limited to 58 lines followed by a form feed
on a line by itself.
* Each line must be limited to 72 characters followed by carriage
return and line feed.
* No overstriking (or underlining) is allowed.
* These "height" and "width" constraints include any headers,
footers, page numbers, or left side indenting.
* Do not fill the text with extra spaces to provide a straight
right margin.
* Do not do hyphenation of words at the right margin.
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* Do not use footnotes. If such notes are necessary, put them at
the end of a section, or at the end of the document.
* Use single spaced text within a paragraph, and one blank line
between paragraphs.
* Note that the number of pages in a document and the page
numbers on which various sections fall will likely change with
reformatting. Thus cross references in the text by section
number usually are easier to keep consistent than cross
references by page number.
* RFCs in plain ASCII-text may be submitted to the RFC Editor in
e-mail messages (or as online files) in either the finished
Publication format or in nroff. If you plan to submit a
document in nroff please consult the RFC Editor first.
Precedent for multiple Publication formats is described in RFC 2223
and has been used for a few RFCs:
Note that since the ASCII text version of the RFC is the primary
version, the PostScript version must match the text version. The
RFC Editor must decide if the PostScript version is "the same as"
the ASCII version before the PostScript version can be published.
Neither RFC 2223 or 2223bis use the term 'metadata,' though the RFC
Editor currently refers to components of the text such as the Stream,
Status (e.g. Updates, Obsoletes), Category and ISSN as 'metadata.'
2.1. Issues driving change
While some authors and readers of RFCs find the strict limits of
character encoding, line limits, and so on to be acceptable, others
find those limitations a significant obstacle to their desire to
communicate information via an RFC. With a broader community of
authors currently producing RFCs and a wider range of presentation
devices, the issues driving change represent both critical
deficiencies in the current Canonical format as well as strongly
desirable changes on the part of some segments of the Internet
community.
While the specific points of concern vary, the main issues are:
* Line art, also known as ASCII art
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* Character encoding
* Pagination
* Reflowable text
* Metadata
Each area of concern has people in favor of change and people opposed
to it, all with reasonable concerns and requirements. Below is a
summary of the arguments for and against each major issue. The
potential requirements derived from these discussions are listed
later in this document.
2.1.1. Line art, aka ASCII art
Arguments in favor of keeping the current requirement for all
diagrams, equations, tables, and charts include:
* Dependence on advanced diagrams (or any diagrams) causes
accessibility issues
* Requiring ASCII art results in people often relying more on
clear written descriptions rather than just the diagram
itself.
* Use of the ASCII character set forces design of diagrams that
are simple and concise..
Arguments in favor of replacing ASCII art with more complex diagrams
include:
* State diagrams with multiple arrows in different directions and
labels on the lines will be more understandable.
* Protocol flow diagrams where each step needs multiple lines of
description will be clearer.
* Scenario descriptions that involve three or more parties with
communication flows between them will be clearer.
* Given the difficulties in expressing complex equations with
common mathematical notation, allowing graphic art would allow
equations to be displayed properly.
* Complex art could allow for color to be introduced into the
diagrams.
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Two suggestions have been been proposed regarding how graphics should
be included: one that would have graphic art referenced as a separate
document to the Publication format, and one that would allow embedded
graphics in the Publication format.
2.1.2. Character encoding
For most of the history of the RFC Series, the character encoding for
RFCs has been ASCII. Below are arguments for keeping ASCII as well
as arguments for expanding to UTF-8.
Arguments for retaining the ASCII-only requirement
* Most easily searched and displayed across a variety of
platforms.
* In extreme cases of having to retype/scan hard copies of
documents (it has been required in the past) ASCII is
significantly easier to work with for rescanning and retaining
all of the original information. There can be no loss of
descriptive metadata such as keywords or content tags.
* If we expand beyond ASCII, it will be difficult to know where
to draw the line on what characters are and are not allowed.
There will be issues with dependencies on local file systems
and processors being configured to recognize any other
character set.
* The IETF works in ASCII (and English). The Internet research,
design and development communities function almost entirely in
English. That strongly suggests that an ASCII document can be
read by everyone in the communities and audiences of interest.
Arguments for expanding to allow UTF-8:
* In discussions of internationalization, actually being able to
illustrate the issue is rather helpful, and you can't
illustrate a Unicode code point with "U+nnnn".
* Will provide the ability to denote protocol examples using the
character sets those examples support.
* Will allow better support for international character sets, in
particular allowing authors to spell their names in their
native character sets.
* Certain special characters in equations or quoted from other
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texts could be allowed.
* Citations of web pages using more international characters are
possible.
Arguments for strictly prescribed UTF-8 use:
* In order to keep documents as searchable as possible, ASCII-only
should be required for the main text of the document and some
broader UTF-8 character set allowed under clearly prescribed
circumstances (e.g. author names and references).
2.1.3. Pagination
Arguments for continuing the use of discrete pages within RFCs:
* Ease of reference and clear printing; referring to section
numbers is too coarse a method
Arguments for removing the pagination requirement:
* Removing pagination will allow for a smoother reading
experience on a wider variety of devices, platforms, and
browsers
2.1.4. Reflowable text
Arguments against allowing for reflowable text:
* Reflowable text may impact the usability of graphics and tables
within a document.
Arguments for allowing reflowable text
* RFCs are more readable on a wider variety of devices and
platforms, including mobile devices and a wide variety of
screen layouts.
2.1.5. Metadata and tagging
While metadata requirements are not part of RFC 2223, there is a
request that descriptive metadata tags be added as part of a revision
of the Canonical RFC format. These tags would allow for enhanced
content by embedding information like links, tags, or quick
translations and could help control the look and feel of the
Publication format. While the lack of metadata in the current RFCs
does not impact an RFCs accessibility or readability, if other
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requirements are accepted, such as allowing UTF-8 in any part of an
RFC, then having the ability to use metadata to provide an ASCII
"translation" of the UTF-8 letters is also a requirement.
Arguments for allowing metadata in the Canonical and Publication
formats:
* Allowing metadata in the final Canonical and Publication format
allows readers to potentially get more detail out of a
document. For example, if non-ASCII characters are allowed in
the Author and Reference sections, Metadata must include
translations of that information.
Arguments against metadata in the final Canonical and Publication
formats:
* Metadata adds additional overhead to the overall process of
creating RFCs and may complicate future usability.
2.2. Further considerations
Some of the discussion beyond the issues described above went into
potential solutions. Those solutions and the debate around them
added a few more points to the potential requirements for a change in
RFC Format. In particular, discussing whether a change in format
should also include the creation and ongoing support of specific RFC
authoring and/or rendering tools and whether the Canonical format
should be a format that must go through a rendering agent to be
readable.
2.2.1. Creation and use of RFC-specific tools
Arguments against community-supported RFC-specific tools:
* We cannot be so unique in our needs that we can't use
commercial tools.
* Ongoing support for these tools adds a greater level of
instability to the ongoing availability of the RFC Series
through the decades.
* The community that would support these tools cannot be relied
on to be as stable and persistent as the Series itself.
Arguments in support of community-supported RFC-specific tools:
* Given the community that would be creating and supporting these
tools, there would be greater control and flexibility over the
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tools and how they implement the RFC format requirements.
* Community supported tools currently exist and are in extensive
use within the community, so it would be most efficient to
build on that base.
2.2.2. Markup Language
Arguments in support of a markup language as the Revisable format:
* Having a markup language such as XML or HTML allows for greater
flexibility in creating a variety of Publication formats, with
a greater likelihood of similarity between them.
Arguments against a markup language as the Revisable format:
* Having the Publication format be in code instead of in a simple
text-formatting structure ties us in to specific tools and/or
tool support going forward.
2.3. RFC Editor goals
Today, each RFC has an nroff file created prior to publication. For
RFCs revised using an XML file, this file is created by converting
XML to nroff at the final step. As more documents are submitted with
an XML file (so far in 2012, 66% of approved I-Ds were submitted with
an XML file), this conversion is problematic in terms of time spent
and data lost from XML. Making this process more efficient is
strongly desired by the RFC Editor.
3. Format requirements
Understanding the major pain points and balancing them with the
expectation of long-term viability of the documents brings us to a
review of what must be kept of the original requirements, what new
requirements may be added, and what requirements may be retired.
3.1. Original requirements to be retained
There are several components of the original format requirements that
must be retained to ensure the ongoing continuity, reliability and
readability of the Series:
* RFCs must not change, regardless of format, once published.
* The Canonical format must be persistent and reliable across a
large variety of devices, operating systems, and editing tools
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for the indefinite future.
* While several Publication formats must be allowed, the
Publication formats must include support for plain-text
printing.
* The Boilerplate and overall structure of the RFC must be in
accordance with current RFC and Style Guide requirements (see
[RFC5741]).
Issues such as overstriking, page justification, hyphenation, and
spacing will be defined in the RFC Style Guide. [link required]
3.2. Requirements to be added
In addition to those continuing requirements, discussions with
various members of the wider Internet Community have yielded the
following General Requirements for the RFC Series.
* There must be support for Accessibility, including alternative
text for images, limitations on color. Appropriate authoring
tools are highly desirable but focus on the creation of
Internet-Drafts, a topic outside the scope of the RFC Editor.
[WCAG20]
* The official language of the RFC Series is English. To respect
international names and information, UTF-8/Unicode in the
header and references must be allowed. Romanized ASCII
translations will be required and recorded in the metadata
(that translation will be used in the ASCII text version of the
RFC and to aid in basic searching).
* The Submission and Publication formats need to permit
extensible encoding, for the addition of labeled metadata. A
pre-defined set of metadata tags must be created to make use of
metadata tags consistent for the life of the Series.
* Graphics may include ASCII art and SVG line art. Color will
not be accepted; RFCs must correctly display in monochrome to
allow for monochrome displays, black-and-white printing, and
Accessibility issues.
* RFC must be readable self-contained (i.e. must not contain
normative external links, figures, etc.) in order to be easily
downloaded and read offline.
* Fixed-width fonts are required for ASCII-art sections, source
code examples, and other places where strict alignment is
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required.
The requirements of the RFC Editor in considering how the formats for
Submission and Publication should change include:
* The final conversion of all submitted documents to nroff should
be replaced by using an accepted Revisable format throughout
the process.
* In order to maintain an efficient publication process, the RFC
Editor must work with the minimal number of files required for
each submission (not a tar ball of several discrete
components).
* In order to maintain the focus of the RFC Editor on editing for
clarity and consistency rather than document layout details,
the number of Publication formats must be limited.
* Tools must support error checking against document layout
issues as well as other format details (diagrams, line breaks,
variable and fixed width font layout) at the time of Submission
for author review.
3.3. Requirements to be retired
Some of the original requirements may be removed from consideration:
* Pagination ("Each page must be limited to 58 lines followed by
a form feed on a line by itself.")
* Maximum line length ("Each line must be limited to 72
characters followed by carriage return and line feed.")
* Limitation to 100% ASCII text ("The character codes are
ASCII.")
4. Security Considerations
This document sets out requirements for RFCs in their various
formats, it does not concern interactions between Internet
hosts. Therefore it does not have any specific Security
Considerations.
5. IANA Considerations
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This document does not request entries in any IANA Registry.
6. References
6.1. Normative References
[WCAG20] W3C, "Web Content Accessibility Guidelines (WCAG) 2.0",
December 11 2008, http://www.w3.org/TR/WCAG20/
6.2. Informative References
[RFC2223] Postel, J. and J. Reynolds, "Instructions to RFC Authors",
RFC 2223, October 1997.
[RFC5741] Daigle, L., Ed., Kolkman, O., Ed., and IAB, "RFC Streams,
Headers, and Boilerplates", RFC 5741, December 2009.
[2223bis] Reynolds, J. Bradon, R., "Instructions to Request for
Comments (RFC) Authors", Work In Progress, August 2004.
Acknowledgements
The authors received a great deal of helpful input from the community
in pulling together these requirements and wish to particularly
acknowledge the help of Joe Hildebrand, Paul Hoffman and John
Klensin, who each published an I-D on the topic of potential format
options before the IETF 84 BOF.
Authors' Addresses
Heather Flanagan
RFC Series Editor
Email: rse@rfc-editor.org
Nevil Brownlee
Independent Submissions Editor
Email rfc-ise@rfc-editor.org
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