Rfc | 7992 |
Title | HTML Format for RFCs |
Author | J. Hildebrand, Ed., P. Hoffman |
Date | December 2016 |
Format: | TXT, HTML |
Status: | INFORMATIONAL |
|
Internet Architecture Board (IAB) J. Hildebrand, Ed.
Request for Comments: 7992 Mozilla
Category: Informational P. Hoffman
ISSN: 2070-1721 ICANN
December 2016
HTML Format for RFCs
Abstract
In order to meet the evolving needs of the Internet community, the
canonical format for RFCs is changing from a plain-text, ASCII-only
format to an XML format that will, in turn, be rendered into several
publication formats. This document defines the HTML format that will
be rendered for an RFC or Internet-Draft.
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 Internet Architecture Board (IAB)
and represents information that the IAB has deemed valuable to
provide for permanent record. It represents the consensus of the
Internet Architecture Board (IAB). Documents approved for
publication by the IAB are not a candidate 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
http://www.rfc-editor.org/info/rfc7992.
Copyright Notice
Copyright (c) 2016 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
(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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Requirements for the HTML Format . . . . . . . . . . . . . . 5
2.1. Requirements for Accessibility . . . . . . . . . . . . . 6
3. HTML Version . . . . . . . . . . . . . . . . . . . . . . . . 7
4. HTML Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. Common Items . . . . . . . . . . . . . . . . . . . . . . . . 8
5.1. IDs . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.2. Pilcrows . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Front Matter . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1. DOCTYPE . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.2. Root Element . . . . . . . . . . . . . . . . . . . . . . 9
6.3. <head> Element . . . . . . . . . . . . . . . . . . . . . 9
6.3.1. Charset Declaration . . . . . . . . . . . . . . . . . 9
6.3.2. Document Title . . . . . . . . . . . . . . . . . . . 10
6.3.3. Document Metadata . . . . . . . . . . . . . . . . . . 10
6.3.4. Link to XML Source . . . . . . . . . . . . . . . . . 10
6.3.5. Link to License . . . . . . . . . . . . . . . . . . . 10
6.3.6. Style . . . . . . . . . . . . . . . . . . . . . . . . 11
6.3.7. Links . . . . . . . . . . . . . . . . . . . . . . . . 11
6.4. Page Headers and Footers . . . . . . . . . . . . . . . . 12
6.5. Document Information . . . . . . . . . . . . . . . . . . 13
6.6. Table of Contents . . . . . . . . . . . . . . . . . . . . 14
7. Main Body . . . . . . . . . . . . . . . . . . . . . . . . . . 14
8. Back Matter . . . . . . . . . . . . . . . . . . . . . . . . . 14
8.1. Index . . . . . . . . . . . . . . . . . . . . . . . . . . 14
8.1.1. Index Contents . . . . . . . . . . . . . . . . . . . 15
8.1.2. Index Letters . . . . . . . . . . . . . . . . . . . . 15
8.1.3. Index Items . . . . . . . . . . . . . . . . . . . . . 16
8.1.4. Index Subitems . . . . . . . . . . . . . . . . . . . 16
8.2. Authors' Addresses Section . . . . . . . . . . . . . . . 17
8.3. Document Information . . . . . . . . . . . . . . . . . . 18
9. Elements . . . . . . . . . . . . . . . . . . . . . . . . . . 18
9.1. <abstract> . . . . . . . . . . . . . . . . . . . . . . . 18
9.2. <address> . . . . . . . . . . . . . . . . . . . . . . . . 19
9.3. <annotation> . . . . . . . . . . . . . . . . . . . . . . 19
9.4. <area> . . . . . . . . . . . . . . . . . . . . . . . . . 19
9.5. <artwork> . . . . . . . . . . . . . . . . . . . . . . . . 20
9.5.1. Text Artwork . . . . . . . . . . . . . . . . . . . . 20
9.5.2. SVG Artwork . . . . . . . . . . . . . . . . . . . . . 20
9.5.3. Other Artwork . . . . . . . . . . . . . . . . . . . . 21
9.6. <aside> . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.7. <author> . . . . . . . . . . . . . . . . . . . . . . . . 21
9.7.1. Authors in Document Information . . . . . . . . . . . 22
9.7.2. Authors of This Document . . . . . . . . . . . . . . 22
9.7.3. Authors of References . . . . . . . . . . . . . . . . 24
9.8. <back> . . . . . . . . . . . . . . . . . . . . . . . . . 24
9.9. <bcp14> . . . . . . . . . . . . . . . . . . . . . . . . . 25
9.10. <blockquote> . . . . . . . . . . . . . . . . . . . . . . 25
9.11. <boilerplate> . . . . . . . . . . . . . . . . . . . . . . 26
9.12. <br> . . . . . . . . . . . . . . . . . . . . . . . . . . 26
9.13. <city> . . . . . . . . . . . . . . . . . . . . . . . . . 26
9.14. <code> . . . . . . . . . . . . . . . . . . . . . . . . . 26
9.15. <country> . . . . . . . . . . . . . . . . . . . . . . . . 26
9.16. <cref> . . . . . . . . . . . . . . . . . . . . . . . . . 27
9.17. <date> . . . . . . . . . . . . . . . . . . . . . . . . . 27
9.18. <dd> . . . . . . . . . . . . . . . . . . . . . . . . . . 27
9.19. <displayreference> . . . . . . . . . . . . . . . . . . . 27
9.20. <dl> . . . . . . . . . . . . . . . . . . . . . . . . . . 27
9.21. <dt> . . . . . . . . . . . . . . . . . . . . . . . . . . 27
9.22. <em> . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.23. <email> . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.24. <eref> . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.25. <figure> . . . . . . . . . . . . . . . . . . . . . . . . 28
9.26. <front> . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.27. <iref> . . . . . . . . . . . . . . . . . . . . . . . . . 29
9.28. <keyword> . . . . . . . . . . . . . . . . . . . . . . . . 29
9.29. <li> . . . . . . . . . . . . . . . . . . . . . . . . . . 29
9.30. <link> . . . . . . . . . . . . . . . . . . . . . . . . . 29
9.31. <middle> . . . . . . . . . . . . . . . . . . . . . . . . 29
9.32. <name> . . . . . . . . . . . . . . . . . . . . . . . . . 29
9.33. <note> . . . . . . . . . . . . . . . . . . . . . . . . . 30
9.34. <ol> . . . . . . . . . . . . . . . . . . . . . . . . . . 30
9.34.1. Percent Styles . . . . . . . . . . . . . . . . . . . 30
9.34.2. Standard Styles . . . . . . . . . . . . . . . . . . 30
9.35. <organization> . . . . . . . . . . . . . . . . . . . . . 31
9.36. <phone> . . . . . . . . . . . . . . . . . . . . . . . . . 31
9.37. <postal> . . . . . . . . . . . . . . . . . . . . . . . . 31
9.38. <postalLine> . . . . . . . . . . . . . . . . . . . . . . 32
9.39. <refcontent> . . . . . . . . . . . . . . . . . . . . . . 32
9.40. <reference> . . . . . . . . . . . . . . . . . . . . . . . 33
9.41. <referencegroup> . . . . . . . . . . . . . . . . . . . . 33
9.42. <references> . . . . . . . . . . . . . . . . . . . . . . 34
9.43. <region> . . . . . . . . . . . . . . . . . . . . . . . . 34
9.44. <relref> . . . . . . . . . . . . . . . . . . . . . . . . 35
9.44.1. displayFormat='of' . . . . . . . . . . . . . . . . . 35
9.44.2. displayFormat='comma' . . . . . . . . . . . . . . . 35
9.44.3. displayFormat='parens' . . . . . . . . . . . . . . . 36
9.44.4. displayFormat='bare' . . . . . . . . . . . . . . . . 36
9.45. <rfc> . . . . . . . . . . . . . . . . . . . . . . . . . . 37
9.46. <section> . . . . . . . . . . . . . . . . . . . . . . . . 37
9.47. <seriesInfo> . . . . . . . . . . . . . . . . . . . . . . 37
9.48. <sourcecode> . . . . . . . . . . . . . . . . . . . . . . 38
9.49. <street> . . . . . . . . . . . . . . . . . . . . . . . . 38
9.50. <strong> . . . . . . . . . . . . . . . . . . . . . . . . 38
9.51. <sub> . . . . . . . . . . . . . . . . . . . . . . . . . . 38
9.52. <sup> . . . . . . . . . . . . . . . . . . . . . . . . . . 38
9.53. <t> . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
9.54. <table> . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.55. <tbody> . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.56. <td> . . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.57. <tfoot> . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.58. <th> . . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.59. <thead> . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.60. <title> . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.61. <tr> . . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.62. <tt> . . . . . . . . . . . . . . . . . . . . . . . . . . 40
9.63. <ul> . . . . . . . . . . . . . . . . . . . . . . . . . . 40
9.64. <uri> . . . . . . . . . . . . . . . . . . . . . . . . . . 40
9.65. <workgroup> . . . . . . . . . . . . . . . . . . . . . . . 40
9.66. <xref> . . . . . . . . . . . . . . . . . . . . . . . . . 40
9.67. <svg xmlns='http://www.w3.org/2000/svg'> . . . . . . . . 41
10. Security Considerations . . . . . . . . . . . . . . . . . . . 41
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 41
11.1. Normative References . . . . . . . . . . . . . . . . . . 41
11.2. Informative References . . . . . . . . . . . . . . . . . 42
IAB Members at the Time of Approval . . . . . . . . . . . . . . . 43
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 43
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 43
1. Introduction
As described in [RFC7990], the RFC Series is changing. One of those
changes includes the RFC Editor publishing a non-canonical HTML
version of RFCs.
This document describes the HTML format that will be used as one of
the publication formats for the RFC Series. It defines a strict
subset of HTML appropriate for RFC Series documents. The visual
layout of the document will be defined through a cascading style
sheet (CSS) [W3C.REC-CSS2-20110607]. The CSS will be included in the
HTML file but will be described in [RFC7993].
The details (particularly any vocabularies) described in this
document are expected to change based on experience gained in
implementing the new publication toolsets. Revised documents will be
published capturing those changes as the toolsets are completed.
Other implementers must not expect those changes to remain backwards
compatible with the details described in this document.
2. Requirements for the HTML Format
This section lists the design requirements used to create the HTML
format described in this document. These requirements build on those
found in [RFC6949]. Many of these requirements are naturally
fulfilled by using the output of the preparation tool [RFC7998].
o The HTML has to render correctly on a list of browser versions
that the RFC Editor will keep up to date outside of this document.
o The format will consist of a subset of HTML deemed to be widely
implemented by common browsers at the time the specification is
created, likely to continue to be widely implemented, and unlikely
to cause security issues. This will maximize the chances that
future HTML renderers (such as new web browsers) will continue to
produce readable text from the HTML format without the format
needing to be changed frequently.
o These requirements are expected to change in the future to reflect
the expectation that HTML rendering will be required for current
versions of browsers and platforms, while ideally continuing to
render correctly on recent versions of those browsers.
o The HTML documents from the RFC Editor or Internet-Drafts
directory may be re-rendered from the canonical XML format in the
future to ensure the ongoing readability of the documents. The
intent is that any re-rendering would be due to exceptional
circumstances rather than for minor annoyances.
o The HTML must display adequately in at least one text-based
browser. Some consumers of the RFC Series can only access the
documents on text-based terminals.
o The HTML document will be self-contained, without requiring
external files for images, CSS, JavaScript, or the like. This
will allow the HTML file to be moved over various non-HTTP
transports (such as email, FTP, and rsync) without breakage.
o JavaScript will be supported on a limited basis. It will not be
permitted to overwrite or change any text present in the rendered
HTML. It may, on a limited basis, add additional text that
provides post-publication metadata or pointers if warranted. All
such text will be clearly marked as additional.
o The HTML document will allow easy local override of the default
CSS formatting. This will allow users who have a different visual
style that they prefer to make RFCs display with that style
without having to alter the contents of the HTML document. This
might also be valuable for allowing people with specific
accessibility needs to use a customized CSS.
o HTML tags in documents will rarely have attributes whose only
purpose is to affect the rendered styling, and those will only be
used if it would not be possible to specify that styling in a CSS.
No such attributes are known at this time.
o Both user-defined and auto-generated anchors must be supported and
linkable, with user-defined anchors appearing in an "id"
attribute. Auto-generated anchors will be generated for every
heading, paragraph, and so on, not just those that do not have
user-defined anchors. User-defined anchors may, and auto-
generated anchors will, appear next to paragraphs, figures,
tables, blockquotes, and section titles.
o All sections, subsections, figures, and paragraphs should have
stable numbered link anchors. Additionally, anchors expressed in
the source XML should be exposed as anchors in the HTML output as
well.
o The HTML must make it easy to separate sections along with all of
their subsections into separate files. This will make creating
EPUB documents easier in the future.
o The HTML produced for Internet-Drafts will differ from that
produced by the RFC Editor due to differences in the output from
the prep tool.
o The abstract must be marked up or tagged in a way that popular
search engines will extract it as a summary.
2.1. Requirements for Accessibility
o Normative information must be easily accessible to the following
consumers:
* People with impaired vision, including those that use large
fonts and those that use screen readers
* People with difficulty distinguishing between colors
* People who use devices with small screens, such as cell phones
o Specific instances where goals for accessibility are important in
the design choices of the format have been called out in the text.
o Note: designing for these consumers does not preclude the use of
features they cannot use, but it does require that key semantic
data not be lost when read using the tools and settings that are
required by a given constituency.
3. HTML Version
The RFC Editor will periodically determine which version of the HTML
specification will be referenced for tools generating the format
defined in this document. The starting version will be that defined
in [W3C.REC-html5-20141028], commonly known as "HTML5". Although the
HTML specification mandates several of the syntax and structure rules
described in this document, they are called out here for emphasis.
4. HTML Syntax
The processor emitting HTML from the XML source will follow these
rules:
o The HTML output is encoded as UTF-8, as specified in [RFC3629].
o The document is valid HTML.
o Double quotes (U+0022 QUOTATION MARK: ") are used to quote
attribute values unless the HTML specification forbids quoting a
particular attribute.
o Each logical line is terminated solely with a \n (U+000A: LINE
FEED), otherwise known as "Unix-style" line endings.
o Code points below (U+0020: SPACE) or character entity references
that generate them (e.g. 	), other than (U+000A: LINE FEED) may
not be used. Note: this rule explicitly forbids \t (U+0009:
CHARACTER TABULATION), \f (U+000C: FORM FEED), and \r (U+000D:
CARRIAGE RETURN) from appearing in the HTML output.
o Comments in the source XML, if any, will not be copied into the
HTML.
o The HTML output will be pretty-printed, using whatever consistent
rules are deemed best by the developers of the HTML production
tools.
Note: none of these rules affect the rendered output of the HTML, but
they are intended to increase the chance that text comparison tools
(e.g., "diff") that operate on the HTML output are easier to write.
5. Common Items
This section lists items that are common across multiple parts of the
HTML document.
5.1. IDs
HTML elements that are generated from XML elements that include an
"anchor" attribute will use the value of the "anchor" attribute as
the value of the "id" attribute of the corresponding HTML element.
The prep tool produces XML with "anchor" attributes in all elements
that need them. Some HTML constructs (such as <section>) will use
multiple instances of these identifiers.
5.2. Pilcrows
Each paragraph, artwork, or sourcecode segment outside of a <figure>
or <table> element will be appended with a space and a "pilcrow"
(U+00B6: PILCROW SIGN), otherwise known as a "paragraph sign". For
the purposes of clarity in ASCII renderings of this document, in this
document pilcrows are rendered as "¶". The pilcrow will be
linked to the "id" attribute on the XML entity to which it is
associated using an <a> element of class "pilcrow". For example:
<p id="s-1.1-1">
Some paragraph text. <a class="pilcrow" href="#s-1.1-1">¶</a>
</p>
The pilcrow will normally be invisible unless the element it is
attached to is moused over. The pilcrow will be surrounded by a link
that points to the element it is attached to.
Pilcrows are never included inside a <table> or <figure> element,
since the figure number or table number serves as an adequate link
target.
Elements that might otherwise contain a pilcrow do not get marked
with a pilcrow if they contain one or more child elements that are
marked with a pilcrow. For example:
<blockquote id="s-1.2-1">
<p id="s-1.2-2">Four score and seven years ago our fathers brought
forth on this continent, a new nation, conceived in Liberty, and
dedicated to the proposition that all men are created equal.
<a href="#s-1.2-2" class="pilcrow">¶</a></p>
<!-- NO pilcrow here -->
</blockquote>
6. Front Matter
The front matter of the HTML format contains processing information,
metadata of various types, and styling information that applies to
the document as a whole. This section describes HTML that is not
necessarily a direct transform from the XML format. For more details
on each of the tags that generate content in this section, see
Section 9.
6.1. DOCTYPE
The DOCTYPE of the document is "html", which declares that the
document is compliant with HTML5. The document will start with
exactly this string:
<!DOCTYPE html>
6.2. Root Element
The root element of the document is <html>. This element includes a
"lang" attribute, whose value is a language tag, as discussed in
[RFC5646], that describes the natural language of the document. The
language tag to be included is "en". The class of the <html> element
will be copied verbatim from the XML <rfc> element's <front>
element's <seriesInfo> element's "name" attributes (separated by
spaces; see Section 2.47.3 of [RFC7991]), allowing CSS to style RFCs
and Internet-Drafts differently from one another (if needed):
<html lang="en" class="RFC">
6.3. <head> Element
The root <html> will contain a <head> element that contains the
following elements, as needed.
6.3.1. Charset Declaration
In order to be correctly processed by browsers that load the HTML
using a mechanism that does not provide a valid content-type or
charset (such as from a local file system using a "file:" URL), the
HTML <head> element contains a <meta> element, whose "charset"
attribute value is "utf-8":
<meta charset="utf-8">
6.3.2. Document Title
The contents of the <title> element from the XML source will be
placed inside an HTML <title> element in the header.
6.3.3. Document Metadata
The following <meta> elements will be included:
o author - one each for the each of the "fullname"s and
"asciiFullname"s of all of the <author>s from the <front> of the
XML source
o description - the <abstract> from the XML source
o generator - the name and version number of the software used to
create the HTML
o keywords - comma-separated <keyword>s from the XML source
For example:
<meta name="author" content="Joe Hildebrand">
<meta name="author" content="JOE HILDEBRAND">
<meta name="author" content="Heather Flanagan">
<meta name="description" content="This document defines...">
<meta name="generator" content="xmljade v0.2.4">
<meta name="keywords" content="html,css,rfc">
Note: the HTML <meta> tag does not contain a closing slash.
6.3.4. Link to XML Source
The <head> element contains a <link> tag, with "rel" attribute of
"alternate", "type" attribute of "application/rfc+xml", and "href"
attribute pointing to the prepared XML source that was used to
generate this document.
<link rel="alternate" type="application/rfc+xml" href="source.xml">
6.3.5. Link to License
The <head> element contains a <link> tag, with "rel" attribute of
"license" and "href" attribute pointing to the an appropriate
copyright license for the document.
<link rel="license"
href="https://trustee.ietf.org/trust-legal-provisions.html">
6.3.6. Style
The <head> element contains an embedded CSS in a <style> element.
The styles in the style sheet are to be set consistently between
documents by the RFC Editor, according to the best practices of the
day.
To ensure consistent formatting, individual style attributes should
not be used in the main portion of the document.
Different readers of a specification will desire different formatting
when reading the HTML versions of RFCs. To facilitate this, the
<head> element also includes a <link> to a style sheet in the same
directory as the HTML file, named "rfc-local.css". Any formatting in
the linked style sheet will override the formatting in the included
style sheet. For example:
<style>
body {}
...
</style>
<link rel="stylesheet" type="text/css" href="rfc-local.css">
6.3.7. Links
Each <link> element from the XML source is copied into the HTML
header. Note: the HTML <link> element does not include a closing
slash.
6.4. Page Headers and Footers
In order to simplify printing by HTML renderers that implement
[W3C.WD-css3-page-20130314], a hidden HTML <table> tag of class
"ears" is added at the beginning of the HTML <body> tag, containing
HTML <thead> and <tfoot> tags, each of which contains an HTML <tr>
tag, which contains three HTML <td> tags with class "left", "center",
and "right", respectively.
The <thead> corresponds to the top of the page, the <tfoot> to the
bottom. The string "[Page]" can be used as a placeholder for the
page number. In practice, this must always be in the <tfoot>'s right
<td>, and no control of the formatting of the page number is implied.
<table class="ears">
<thead>
<tr>
<td class="left">Internet-Draft</td>
<td class="center">HTML RFC</td>
<td class="right">March 2016</td>
</tr>
</thead>
<tfoot>
<tr>
<td class="left">Hildebrand</td>
<td class="center">Expires September 2, 2016</td>
<td class="right">[Page]</td>
</tr>
</tfoot>
</table>
6.5. Document Information
Information about the document as a whole will appear as the first
child of the HTML <body> element, embedded in an HTML <dl> element
with id="identifiers". The defined terms in the definition list are
"Workgroup:", "Series:", "Status:", "Published:", and "Author:" or
"Authors:" (as appropriate). For example:
<dl id="identifiers">
<dt>Workgroup:</dt>
<dd class="workgroup">rfc-interest</dd>
<dt>Series:</dt>
<dd class="series">Internet-Draft</dd>
<dt>Status:</dt>
<dd class="status">Informational</dd>
<dt>Published:</dt>
<dd><time datetime="2014-10-25"
class="published">2014-10-25</time></dd>
<dt>Authors:</dt>
<dd class="authors">
<div class="author">
<span class="initial">J.</span>
<span class="surname">Hildebrand</span>
(<span class="organization">Cisco Systems, Inc.</span>)
<span class="editor">Ed.</span>
</div>
<div class="author">
<span class="initial">H.</span>
<span class="surname">Flanagan</span>
(<span class="organization">RFC Editor</span>)
</div>
</dd>
</dl>
6.6. Table of Contents
The table of contents will follow the boilerplate if the XML's <rfc>
element's "tocInclude" attribute has the value "true". An HTML <h2>
heading containing the text "Table of Contents" will be followed by a
<nav> element that contains a <ul> element for each depth of the
section hierarchy. Each section will be represented by a <li>
element containing links by the section number (from the "pn"
attribute) and by the name (from the "slugifiedName" attribute of the
<name> child element). Each <nav>, <ul>, and <li> element will have
the class "toc".
For example:
<h2 id="toc">Table of Contents</h2>
<nav class="toc">
<ul class="toc">
<li class="toc">
<a href="s-1">1</a>. <a href="n-introduction">Introduction</a>
</li>
<ul class="toc">
<li class="toc">
<a href="s-1.1">1.1</a>. <a href="n-sub-intro">Sub Intro</a>
</li>
...
7. Main Body
The main body of the HTML document is processed according to the
rules in Section 9.
8. Back Matter
The back matter of the HTML document includes an index (if
generated), information about the authors, and further information
about the document itself.
8.1. Index
The index will be produced as dictated by the RFC Editor's Style
Guide [RFC-STYLE] if and only if the XML document's <rfc> element has
an "indexInclude" attribute with the value "true" and there is one or
more <iref> elements in the document.
8.1.1. Index Contents
The index section will start with an <h2> heading containing the text
"Index", followed by links to each of the lettered portions of the
index. Links are not generated for letters that do not occur as the
first letter of an index item.
For example:
<h2>Index</h2>
<div class="index">
<div class="indexIndex">
<a href="#rfc.index.C">C</a>
<a href="#rfc.index.P">P</a>
</div>
...
8.1.2. Index Letters
The index letter is followed by a <ul> tag that contains an <li> tag
for each first letter represented in the index. This <li> tag has
the class "indexChar" and contains an <a> tag with the id pointed to
by the index letter as well as an "href" attribute to itself. The
<li> tag also includes a <ul> tag that will contain the index items.
For example:
<ul>
<li class="indexChar">
<a href="#rfc.index.C" id="rfc.index.C">C</a>
<ul>
<!-- items go here -->
</ul>
</li>
...
8.1.3. Index Items
Each index item can have multiple <iref> elements to point to, all
with the same item attribute. Each index item is represented by an
<li> tag of class "indexItem" containing a <span> of class "irefItem"
for the item text and one of class "irefRefs" for the generated
references (if there is at least one reference to the item not having
a subitem). Each generated reference contains an <a> tag containing
the section number where the <iref> is found, with an "href"
attribute pointing to the "irefid" attribute of the <iref> element
from the XML document. If the primary attribute of the <iref>
element has the value "true", the <a> element in the HTML document
will have the class "indexPrimary". Commas may be used to separate
the generated references.
For example:
<li class="indexItem">
<span class="irefItem">Bullets</span>
<span class="irefRefs">
<a class="indexPrimary" href="#s-Bullets-1">2</a>,
<a href="#s-Bullets-2">2</a>
</span>
<!-- subitems go here -->
</li>
...
8.1.4. Index Subitems
If an index item has at least one subitem, the <li> of that item will
contain a <ul>, with one <li> for each subitem, of class
"indexSubItem". The format for each subitem is similar to that used
for items, except the class of the first <span> tag is "irefSubItem".
For example:
<ul>
<li class="indexSubItem">
<span class="irefSubItem">Ordered</span>
<span class="irefRefs">
<a href="#s-Bullets-Ordered-1">2</a>
</span>
</li>
</ul>
...
8.2. Authors' Addresses Section
At the end of the document, author information will be included
inside an HTML <section> element whose "id" attribute is "author-
addresses". The class names of the constituent HTML tags have been
chosen to match the class names in [HCARD].
The information for each author will be separated by an HTML <hr>
element with class "addr".
<section id="author-addresses">
<h2>
<a class="selfRef" href="#author-addresses">
Authors' Addresses
</a>
</h2>
<address class="vcard">
<div class="nameRole"><span class="fn">Joe Hildebrand</span>
(<span class="role">editor</span>)</div>
<div class="org">Cisco Systems, Inc.</div>
</address>
<hr class="addr">
<address class="vcard">
<div class="nameRole"><span class="fn">Heather Flanagan</span>
(<span class="role">editor</span>)</div>
<div class="org">RFC Series Editor</div>
</address>
</section>
8.3. Document Information
A few bits of metadata about the document that are less important to
most readers are included after the author information. These are
gathered together into a <div> of class "docInfo".
The finalized time is copied from the <rfc> element's "prepTime"
attribute. The rendered time is the time that this HTML was
generated.
For example:
<div class="docInfo">
<span class="finalized">
Finalized: <time
datetime="2015-04-29T18:59:08Z">2015-04-29T18:59:08Z</time>
</span>
<span class="rendered">
Rendered: <time
datetime="2015-04-29T18:59:10Z">2015-04-29T18:59:10Z</time>
</span>
</div>
9. Elements
This section describes how each of the XML elements from [RFC7991] is
rendered to HTML. Many of the descriptions have examples to clarify
how elements will be rendered.
9.1. <abstract>
The abstract is rendered in a similar fashion to a <section> with
anchor="abstract" and <name>Abstract</name>, but without a section
number.
<section id="abstract">
<h2><a href="#abstract" class="selfRef">Abstract</a></h2>
<p id="s-abstract-1">This document defines...
<a href="#s-abstract-1" class="pilcrow">¶</a>
</p>
</section>
9.2. <address>
This element is used in the Authors' Addresses section. It is
rendered as an HTML <address> tag of class "vcard". If none of the
descendant XML elements has an "ascii" attribute, the <address> HTML
tag includes the HTML rendering of each of the descendant XML
elements. Otherwise, the <address> HTML tag includes an HTML <div>
tag of class "ascii" (containing the HTML rendering of the ASCII
variants of each of the descendant XML elements), an HTML <div> tag
of class "alternative-contact", (containing the text "Alternate
contact information:"), and an HTML <div> tag of class "non-ascii"
(containing the HTML rendering of the non-ASCII variants of each of
the descendant XML elements).
Note: the following example shows some ASCII equivalents that are the
same as their nominal equivalents for clarity; normally, the ASCII
equivalents would not be included for these cases.
<address class="vcard">
<div class="ascii">
<div class="nameRole"><span class="fn">Joe Hildebrand</span>
(<span class="role">editor</span>)</div>
<div class="org">Cisco Systems, Inc.</div>
</div>
<div class="alternative-contact">
Alternate contact information:
</div>
<div class="non-ascii">
<div class="nameRole"><span class="fn">Joe Hildebrand</span>
(<span class="role">editor</span>)</div>
<div class="org">Cisco Systems, Inc.</div>
</div>
</address>
9.3. <annotation>
This element is rendered as the text ", " (a comma and a space)
followed by a <span> of class "annotation" at the end of a
<reference> element, the <span> containing appropriately transformed
elements from the children of the <annotation> tag.
<span class="annotation">Some <em>thing</em>.</span>
9.4. <area>
Not currently rendered to HTML.
9.5. <artwork>
Artwork can consist of either inline text or SVG. If the artwork is
not inside a <figure> element, a pilcrow (Section 5.2) is included.
Inside a <figure> element, the figure title serves the purpose of the
pilcrow. If the "align" attribute has the value "right", the CSS
class "alignRight" will be added. If the "align" attribute has the
value "center", the CSS class "alignCenter" will be added.
9.5.1. Text Artwork
Text artwork is rendered inside an HTML <pre> element, which is
contained by a <div> element for consistency with SVG artwork. Note
that CDATA blocks are not a part of HTML, so angle brackets and
ampersands (i.e., <, >, and &) must be escaped as <, >, and
&, respectively.
The <div> element will have CSS classes of "artwork", "art-text", and
"art-" prepended to the value of the <artwork> element's "type"
attribute, if it exists.
<div class="artwork art-text art-ascii-art" id="s-1-2">
<pre>
______________
< hello, world >
--------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||
</pre>
<a class="pilcrow" href="#s-1-2">¶</a>
</div>
9.5.2. SVG Artwork
SVG artwork will be included inline. The SVG is wrapped in a <div>
element with CSS classes "artwork" and "art-svg".
If the SVG "artwork" element is a child of <figure> and the artwork
is specified as align="right", an empty HTML <span> element is added
directly after the <svg> element, in order to get right alignment to
work correctly in HTML rendering engines that do not support the
flex-box model.
Note: the "alt" attribute of <artwork> is not currently used for SVG;
instead, the <title> and <desc> tags are used in the SVG.
<div class="artwork art-svg" id="s-2-17">
<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg">
<desc>Alt text here</desc>
<circle
cx="50" cy="50" r="40"
stroke="green" stroke-width="4" fill="yellow" />
</svg>
<a href="#s-2-17" class="pilcrow">¶</a>
</div>
9.5.3. Other Artwork
Other artwork will have a "src" attribute that uses the "data" URI
scheme defined in [RFC2397]. Such artwork is rendered in an HTML
<img> element. Note: the HTML <img> element does not have a closing
slash.
Note: such images are not yet allowed in RFCs even though the format
supports them. A limited set of "data:" mediatypes for artwork may
be allowed in the future.
<div class="artwork art-logo" id="s-2-58">
<img alt="IETF logo"
src="data:image/gif;charset=utf-8;base64,...">
<a class="pilcrow" href="#s-2-58">¶</a>
</div>
9.6. <aside>
This element is rendered as an HTML <aside> element, with all child
content appropriately transformed.
<aside id="s-2.1-2">
<p id="s-2.1-2.1">
A little more than kin, and less than kind.
<a class="pilcrow" href="#s-2.1-2.1">¶</a>
</p>
</aside>
9.7. <author>
The <author> element is used in several places in the output.
Different rendering is used for each.
9.7.1. Authors in Document Information
As seen in the Document Information at the beginning of the HTML,
each document author is rendered as an HTML <div> tag of class
"author".
Inside the <div class="author"> HTML tag, the author's initials and
surname (or the fullname, if it exists and the others do not) will be
rendered in an HTML <div> tag of class "author-name". If the
<author> contains "asciiInitials" and "asciiSurname" attributes, or
contains as "asciiFullname" attribute, the author's name is rendered
twice, with the first being the non-ASCII version, wrapped in an HTML
<span> tag of class "non-ascii", followed by the ASCII version
wrapped in an HTML <span> tag of class "ascii", wrapped in
parentheses. If the <author> has a "role" attribute of "editor", the
<div class="author-name"> will also contain the text ", " (comma,
space), followed by an HTML <span> tag of class "editor", which
contains the text "Ed.".
If the <author> element contains an <organization> element, it is
also rendered inside the <div class="author"> HTML tag.
<div class="author">
<div class="author-name">
H. Flanagan,
<span class="editor">Ed.</span></div>
<div class="org">Test Org</div>
</div>
<div class="author">
<div class="author-name">
<span class="non-ascii">Hildebrand</span>
(<span class="ascii">HILDEBRAND</span>)
</div>
<div class="org">
<span class="non-ascii">Test Org</span>
(<span class="ascii">TEST ORG</span>)
</div>
</div>
9.7.2. Authors of This Document
As seen in the Authors' Addresses section, at the end of the HTML,
each document author is rendered into an HTML <address> element with
the CSS class "vcard".
The HTML <address> element will contain an HTML <div> with CSS class
"nameRole". That div will contain an HTML <span> element with CSS
class "fn" containing the value of the "fullname" attribute of the
<author> XML element and an HTML <span> element with CSS class "role"
containing the value of the "role" attribute of the <author> XML
element (if there is a role). Parentheses will surround the <span
class="role">, if it exists.
<address class="vcard">
<div class="nameRole">
<span class="fn">Joe Hildebrand</span>
(<span class="role">editor</span>)
</div>
...
After the name, the <organization> and <address> child elements of
the author are rendered inside the HTML <address> tag.
When the <author> element, or any of its descendant elements, has any
attribute that starts with "ascii", all of the author information is
displayed twice. The first version is wrapped in an HTML <div> tag
with class "ascii"; this version prefers the ASCII version of
information, such as "asciiFullname", but falls back on the non-ASCII
version if the ASCII version doesn't exist. The second version is
wrapped in an HTML <div> tag with class "non-ascii"; this version
prefers the non-ASCII version of information, such as "fullname", but
falls back on the ASCII version if the non-ASCII version does not
exist. Between these two HTML <div>s, a third <div> is inserted,
with class "alternative-contact", containing the text "Alternate
contact information:".
<address class="vcard">
<div class="ascii">
<div class="nameRole">
<span class="fn">The ASCII name</span>
</div>
</div>
<div class="alternative-contact">
Alternate contact information:
</div>
<div class="non-ascii">
<div class="nameRole">
<span class="fn">The non-ASCII name</span>
(<span class="role">editor</span>)
</div>
</div>
</address>
9.7.3. Authors of References
In the output generated from a reference element, author tags are
rendered inside an HTML <span> element with CSS class "refAuthor".
See Section 4.8.6.2 of [RFC7322] for guidance on how author names are
to appear.
<span class="refAuthor">Flanagan, H.</span> and
<span class="refAuthor">N. Brownlee</span>
9.8. <back>
If there is exactly one <references> child, render that child in a
similar way to a <section>. If there are more than one <references>
children, render as a <section> whose name is "References",
containing a <section> for each <references> child.
After any <references> sections, render each <section> child of
<back> as an appendix.
<section id="n-references">
<h2 id="s-2">
<a class="selfRef" href="#s-2">2.</a>
<a class="selfRef" href="#n-references">References</a>
</h2>
<section id="n-normative">
<h3 id="s-2.1">
<a class="selfRef" href="#s-2.1">2.1.</a>
<a class="selfRef" href="#n-normative">Normative</a>
</h3>
<dl class="reference"></dl>
</section>
<section id="n-informational">
<h3 id="s-2.2">
<a class="selfRef" href="#s-2.2">2.2.</a>
<a class="selfRef" href="#n-informational">Informational</a>
</h3>
<dl class="reference"></dl>
</section>
</section>
<section id="n-unimportant">
<h2 id="s-A">
<a class="selfRef" href="#s-A">Appendix A.</a>
<a class="selfRef" href="#n-unimportant">Unimportant</a>
</h2>
</section>
9.9. <bcp14>
This element marks up words like MUST and SHOULD [BCP14] with an HTML
<span> element with the CSS class "bcp14".
You <span class="bcp14">MUST</span> be joking.
9.10. <blockquote>
This element renders in a way similar to the HTML <blockquote>
element. If there is a "cite" attribute, it is copied to the HTML
"cite" attribute. If there is a "quoteFrom" attribute, it is placed
inside a <cite> element at the end of the quote, with an <a> element
surrounding it (if there is a "cite" attribute), linking to the cited
URL.
If the <blockquote> does not contain another element that gets a
pilcrow (Section 5.2), a pilcrow is added.
Note that the "—" at the beginning of the <cite> element should
be a proper emdash, which is difficult to show in the display of the
current format.
<blockquote id="s-1.2-1"
cite="http://...">
<p id="s-1.2-2">Four score and seven years ago our fathers
brought forth on this continent, a new nation, conceived
in Liberty, and dedicated to the proposition that all men
are created equal.
<a href="#s-1.2-2" class="pilcrow">¶</a>
</p>
<cite>— <a href="http://...">Abraham Lincoln</a></cite>
</blockquote>
9.11. <boilerplate>
The Status of This Memo and the Copyright statement, together
commonly referred to as the document boilerplate, appear after the
Abstract. The children of the input <boilerplate> element are
treated in a similar fashion to unnumbered sections.
<section id="status-of-this-memo">
<h2 id="s-boilerplate-1">
<a href="#status-of-this-memo" class="selfRef">
Status of this Memo</a>
</h2>
<p id="s-boilerplate-1-1">This Internet-Draft is submitted in full
conformance with the provisions of BCP 78 and BCP 79.
<a href="#s-boilerplate-1-1" class="pilcrow">¶</a>
</p>
...
9.12. <br>
This element is directly rendered as its HTML counterpart. Note: in
HTML, <br> does not have a closing slash.
9.13. <city>
This element is rendered as a <span> element with CSS class
"locality".
<span class="locality">Guilford</span>
9.14. <code>
This element is rendered as a <span> element with CSS class "postal-
code".
<span class="postal-code">GU16 7HF<span>
9.15. <country>
This element is rendered as a <div> element with CSS class "country-
name".
<div class="country-name">England</div>
9.16. <cref>
This element is rendered as a <span> element with CSS class "cref".
Any anchor is copied to the "id" attribute. If there is a source
given, it is contained inside the "cref" <span> element with another
<span> element of class "crefSource".
<span class="cref" id="crefAnchor">Just a brief comment
about something that we need to remember later.
<span class="crefSource">--life</span></span>
9.17. <date>
This element is rendered as the HTML <time> element. If the "year",
"month", or "day" attribute is included on the XML element, an
appropriate "datetime" element will be generated in HTML.
If this date is a child of the document's <front> element, it gets
the CSS class "published".
If this date is inside a <reference> element, it gets the CSS class
"refDate".
<time datetime="2014-10" class="published">October 2014</time>
9.18. <dd>
This element is directly rendered as its HTML counterpart.
9.19. <displayreference>
This element does not affect the HTML output, but it is used in the
generation of the <reference>, <referencegroup>, <relref>, and <xref>
elements.
9.20. <dl>
This element is directly rendered as its HTML counterpart.
If the hanging attribute is "false", add the "dlParallel" class, else
add the "dlHanging" class.
If the spacing attribute is "compact", add the "dlCompact" class.
9.21. <dt>
This element is directly rendered as its HTML counterpart.
9.22. <em>
This element is directly rendered as its HTML counterpart.
9.23. <email>
This element is rendered as an HTML <div> containing the string
"Email:" and an HTML <a> element with the "href" attribute set to the
equivalent "mailto:" URI, a CSS class of "email", and the contents
set to the email address. If this is the version of the address with
ASCII, the "ascii" attribute is preferred to the element text.
<div>
<span>Email:</span>
<a class="email" href="mailto:joe@example.com">joe@example.com</a>
</div>
9.24. <eref>
This element is rendered as an HTML <a> element, with the "href"
attribute set to the value of the "target" attribute and the CSS
class of "eref".
<a href="https://..." class="eref">the text</a>
9.25. <figure>
This element renders as the HTML <figure> element, containing the
artwork or sourcecode indicated and an HTML <figcaption> element.
The <figcaption> element will contain an <a> element around the
figure number. It will also contain another <a> element with CSS
class "selfRef" around the figure name, if a name was given.
<figure id="f-1">
...
<figcaption>
<a href="#f-1">Figure 1.</a>
<a href="#n-it-figures" id="n-it-figures" class="selfRef">
It figures
</a>
</figcaption>
</figure>
9.26. <front>
See "Document Information" (Section 6.5) for information on this
element.
9.27. <iref>
This element is rendered as an empty <> tag of class "iref", with an
"id" attribute consisting of the <iref> element's "irefid" attribute:
<span class="iref" id="s-Paragraphs-first-1"/>
9.28. <keyword>
Each <keyword> element renders its text into the <meta> keywords in
the document's header, separated by commas.
<meta name="keywords" content="html,css,rfc">
9.29. <li>
This element is rendered as its HTML counterpart. However, if there
is no contained element that has a pilcrow (Section 5.2) attached, a
pilcrow is added.
<li id="s-2-7">Item <a href="#s-2-7" class="pilcrow">¶</a></li>
9.30. <link>
This element is rendered as its HTML counterpart, in the HTML header.
9.31. <middle>
This element does not add any direct output to HTML.
9.32. <name>
This element is never rendered directly; it is only rendered when
considering a parent element, such as <figure>, <references>,
<section>, or <table>.
9.33. <note>
This element is rendered like a <section> element, but without a
section number and with the CSS class of "note". If the
"removeInRFC" attribute is set to "yes", the generated <div> element
will also include the CSS class "rfcEditorRemove".
<section id="s-note-1" class="note rfcEditorRemove">
<h2>
<a href="#n-editorial-note" class="selfRef">Editorial Note</a>
</h2>
<p id="s-note-1-1">
Discussion of this draft takes place...
<a href="#s-note-1-1" class="pilcrow">¶</a>
</p>
</section>
9.34. <ol>
The output created from an <ol> element depends upon the "style"
attribute.
If the "spacing" attribute has the value "compact", a CSS class of
"olCompact" will be added.
The group attribute is not copied; the input XML should have start
values added by a prep tool for all grouped <ol> elements.
9.34.1. Percent Styles
If the style attribute includes the character "%", the output is a
<dl> tag with the class "olPercent". Each contained <li> element is
emitted as a <dt>/<dd> pair, with the generated label in the <dt> and
the contents of the <li> in the <dd>.
<dl class="olPercent">
<dt>Requirement xviii:</dt>
<dd>Wheels on a big rig</dd>
</dl>
9.34.2. Standard Styles
For all other styles, an <ol> tag is emitted, with any "style"
attribute turned into the equivalent HTML attribute.
<ol class="compact" type="I" start="18">
<li>Wheels on a big rig</li>
</ol>
9.35. <organization>
This element is rendered as an HTML <div> tag with CSS class "org".
If the element contains the "ascii" attribute, the organization name
is rendered twice: once with the non-ASCII version wrapped in an HTML
<span> tag of class "non-ascii" and then as the ASCII version wrapped
in an HTML <span> tag of class "ascii" wrapped in parentheses.
<div class="org">
<span class="non-ascii">Test Org</span>
(<span class="ascii">TEST ORG</span>)
</div>
9.36. <phone>
This element is rendered as an HTML <div> tag containing the string
"Phone:" (wrapped in a span), an HTML <a> tag with CSS class "tel"
containing the phone number (and an href with a corresponding "tel:"
URI), and an HTML <span> with CSS class "type" containing the string
"VOICE".
<div>
<span>Phone:</span>
<a class="tel" href="tel:+1-720-555-1212">+1-720-555-1212</a>
<span class="type">VOICE</span>
</div>
9.37. <postal>
This element renders as an HTML <div> with CSS class "adr", unless it
contains one or more <postalLine> child elements; in which case, it
renders as an HTML <pre> element with CSS class "label".
When there is no <postalLine> child, the following child elements are
rendered into the HTML:
o Each <street> is rendered
o A <div> that includes:
* The rendering of all <city> elements
* A comma and a space: ", "
* The rendering of all <region> elements
* Whitespace
* The rendering of all <code> elements
o The rendering of all <country> elements
<div class="adr">
<div class="street-address">1 Main Street</div>
<div class="street-address">Suite 1</div>
<div>
<span class="city">Denver</span>,
<span class="region">CO</span>
<span class="postal-code">80212</span>
</div>
<div class="country-name">United States of America</div>
</div>
9.38. <postalLine>
This element renders as the text contained by the element, followed
by a newline. However, the last <postalLine> in a given <postal>
element should not be followed by a newline. For example:
<postal>
<postalLine>In care of:</postalLine>
<postalLine>Computer Sciences Division</postalLine>
</postal>
Would be rendered as:
<pre class="label">In care of:
Computer Sciences Division</pre>
9.39. <refcontent>
This element renders as an HTML <span> with CSS class "refContent".
<span class="refContent">Self-published pamphlet</span>
9.40. <reference>
If the parent of this element is not a <referencegroup>, this element
will render as a <dt> <dd> pair with the defined term being the
reference "anchor" attribute surrounded by square brackets and the
definition including the correct set of bibliographic information as
specified by [RFC7322]. The <dt> element will have an "id" attribute
of the reference anchor.
<dl class="reference">
<dt id="RFC5646">[RFC5646]</dt>
<dd>
<span class="refAuthor">Phillips, A.</span>
<span>and</span>
<span class="refAuthor">M. Davis</span>
<span class="refTitle">"Tags for Identifying Languages"</span>,
...
</dd>
</dl>
If the child of a <referencegroup>, this element renders as a <div>
of class "refInstance" whose "id" attribute is the value of the
<source> element's "anchor" attribute.
<div class="refInstance" id="RFC5730">
...
</div>
9.41. <referencegroup>
A <referencegroup> is translated into a <dt> <dd> pair, with the
defined term being the referencegroup "anchor" attribute surrounded
by square brackets, and the definition containing the translated
output of all of the child <reference> elements.
<dt id="STD69">[STD69]</dt>
<dd>
<div class="refInstance" id="RFC5730">
<span class="refAuthor">Hollenbeck, S.</span>
...
</div>
<div class="refInstance" id="RFC5731">
<span class="refAuthor">Hollenbeck, S.</span>
...
</div>
...
</dd>
9.42. <references>
If there is at exactly one <references> element, a section is added
to the document, continuing with the next section number after the
last top-level <section> in <middle>. The <name> element of the
<references> element is used as the section name.
<section id="n-my-references">
<h2 id="s-3">
<a href="#s-3" class="selfRef">3.</a>
<a href="#n-my-references class="selfRef">My References</a>
</h2>
...
</section>
If there is more than one <references> element, an HTML <section>
element is created to contain a subsection for each of the
<references>. The section number will be the next section number
after the last top-level <section> in <middle>. The name of this
section will be "References", and its "id" attribute will be
"n-references".
<section id="n-references">
<h2 id="s-3">
<a href="#s-3" class="selfRef">3.</a>
<a href="#n-references" class="selfRef">References</a>
</h2>
<section id="n-informative-references">
<h3 id="s-3.1">
<a href="#s-3.1" class="selfRef">3.1.</a>
<a href="#n-informative-references" class="selfRef">
Informative References</a></h3>
<dl class="reference">...
</dl>
</section>
...
</section>
9.43. <region>
This element is rendered as a <span> tag with CSS class "region".
<span class="region">Colorado</span>
9.44. <relref>
This element is rendered as an HTML <a> tag with CSS class "relref"
and "href" attribute of the "derivedLink" attribute of the element.
Different values of the "displayFormat" attribute cause the text
inside that HTML <a> tag to change and cause extra text to be
generated. Some values of the "displayFormat" attribute also cause
another HTML <a> tag to be rendered with CSS class "xref" and an
"href" of "#" and the "target" attribute (modified by any applicable
<displayreference> XML element) and text inside of the "target"
attribute (modified by any applicable <displayreference> XML
element). When used, this <a class='xref'> HTML tag is always
surrounded by square brackets, for example, "[<a class='xref'
href='#foo'>foo</a>]".
9.44.1. displayFormat='of'
The output is an <a class='relref'> HTML tag, with contents of
"Section " and the value of the "section" attribute. This is
followed by the word "of" (surrounded by whitespace). This is
followed by the <a class='xref'> HTML tag (surrounded by square
brackets).
For example, with an input of:
See <relref section="2.3" target="RFC9999" displayFormat="of"
derivedLink="http://www.rfc-editor.org/info/rfc9999#s-2.3"/>
for an overview.
The HTML generated will be:
See <a class="relref"
href="http://www.rfc-editor.org/info/rfc9999#s-2.3">Section
2.3</a> of [<a class="xref" href="#RFC9999">RFC9999</a>]
for an overview.
9.44.2. displayFormat='comma'
The output is an <a class='xref'> HTML tag (wrapped by square
brackets), followed by a comma (","), followed by whitespace,
followed by an <a class='relref'> HTML tag, with contents of
"Section " and the value of the "section" attribute.
For example, with an input of:
See <relref section="2.3" target="RFC9999" displayFormat="comma"
derivedLink="http://www.rfc-editor.org/info/rfc9999#s-2.3"/>,
for an overview.
The HTML generated will be:
See [<a class="xref" href="#RFC9999">RFC9999</a>], <a class="relref"
href="http://www.rfc-editor.org/info/rfc9999#s-2.3">Section 2.3</a>,
for an overview.
9.44.3. displayFormat='parens'
The output is an <a> element with "href" attribute whose value is the
value of the "target" attribute prepended by "#", and whose content
is the value of the "target" attribute; the entire element is wrapped
in square brackets. This is followed by whitespace. This is
followed by an <a> element whose "href" attribute is the value of the
"derivedLink" attribute and whose content is the value of the
"derivedRemoteContent" attribute; the entire element is wrapped in
parentheses.
For example, if Section 2.3 of RFC 9999 has the title "Protocol
Overview", for an input of:
See <relref section="2.3" target="RFC9999" displayFormat="parens"
derivedLink="http://www.rfc-editor.org/info/rfc9999#s-2.3"
derivedRemoteContent="Section 2.3"/> for an overview.
The HTML generated will be:
See [<a class="relref" href="#RFC9999">RFC9999</a>]
(<a class="relref"
href="http://www.rfc-editor.org/info/rfc9999#s-2.3">Section
2.3</a>) for an overview.
9.44.4. displayFormat='bare'
The output is an <a> element whose "href" attribute is the value of
the "derivedLink" attribute and whose content is the value of the
"derivedRemoteContent" attribute.
For this input:
See <relref section="2.3" target="RFC9999" displayFormat="bare"
derivedLink="http://www.rfc-editor.org/info/rfc9999#s-2.3"
derivedRemoteContent="Section 2.3"/> and ...
The HTML generated will be:
See <a class="relref"
href="http://www.rfc-editor.org/info/rfc9999#s-2.3">Section
2.3</a> and ...
9.45. <rfc>
Various attributes of this element are represented in different parts
of the HTML document.
9.46. <section>
This element is rendered as an HTML <section> element, containing an
appropriate level HTML heading element (<h2>-<h6>). That heading
element contains an <a> element around the part number (pn), if
applicable (for instance, <abstract> does not get a section number).
Another <a> element is included with the section's name.
<section id="intro">
<h2 id="s-1">
<a href="#s-1" class="selfRef">1.</a>
<a href="#intro" class="selfRef">Introduction</a>
</h2>
<p id="s-1-1">Paragraph <a href="#s-1-1" class="pilcrow">¶</a>
</p>
</section>
9.47. <seriesInfo>
This element is rendered in an HTML <span> element with CSS name
"seriesInfo".
<span class="seriesInfo">RFC 5646</span>
9.48. <sourcecode>
This element is rendered in an HTML <pre> element with a CSS class of
"sourcecode". Note that CDATA blocks do not work consistently in
HTML, so all <, >, and & must be escaped as <, >, and &,
respectively. If the input XML has a "type" attribute, another CSS
class of "lang-" and the type is added.
If the sourcecode is not inside a <figure> element, a pilcrow
(Section 5.2) is included. Inside a <figure> element, the figure
title serves the purpose of the pilcrow.
<pre class="sourcecode lang-c">
#include <stdio.h>
int main(void)
{
printf("hello, world\n");
return 0;
}
</pre>
9.49. <street>
This element renders as an HTML <div> element with CSS class "street-
address".
<div class="street-address">1899 Wynkoop St, Suite 600</div>
9.50. <strong>
This element is directly rendered as its HTML counterpart.
9.51. <sub>
This element is directly rendered as its HTML counterpart.
9.52. <sup>
This element is directly rendered as its HTML counterpart.
9.53. <t>
This element is rendered as an HTML <p> element. A pilcrow
(Section 5.2) is included.
<p id="s-1-1">A paragraph.
<a href="#s-1-1" class="pilcrow">¶</a></p>
9.54. <table>
This element is directly rendered as its HTML counterpart.
9.55. <tbody>
This element is directly rendered as its HTML counterpart.
9.56. <td>
This element is directly rendered as its HTML counterpart.
9.57. <tfoot>
This element is directly rendered as its HTML counterpart.
9.58. <th>
This element is directly rendered as its HTML counterpart.
9.59. <thead>
This element is directly rendered as its HTML counterpart.
9.60. <title>
The title of the document appears in a <title> element in the <head>
element, as described in Section 6.3.2.
The title also appears in an <h1> element and follows directly after
the Document Information. The <h1> element has an "id" attribute
with value "title".
<h1 id="title">HyperText Markup Language Request For
Comments Format</h1>
Inside a reference, the title is rendered as an HTML <span> tag with
CSS class "refTitle". The text is surrounded by quotes inside the
<span>.
<span class="refTitle">"Tags for Identifying Languages"</span>
9.61. <tr>
This element is directly rendered as its HTML counterpart.
9.62. <tt>
This element is rendered as an HTML <code> element.
9.63. <ul>
This element is directly rendered as its HTML counterpart. If the
"spacing" attribute has the value "compact", a CSS class of
"ulCompact" will be added. If the "empty" attribute has the value
"true", a CSS class of "ulEmpty" will be added.
9.64. <uri>
This element is rendered as an HTML <div> containing the string
"URI:" and an HTML <a> element with the "href" attribute set to the
linked URI, CSS class of "url" (note that the value is "url", not
"uri" as one might expect), and the contents set to the linked URI.
<div>URI:
<a href="http://www.example.com"
class="url">http://www.example.com</a>
</div>
9.65. <workgroup>
This element does not add any direct output to HTML.
9.66. <xref>
This element is rendered as an HTML <a> element containing an
appropriate local link as the "href" attribute. The value of the
"href" attribute is taken from the "target" attribute, prepended by
"#". The <a> element generated will have class "xref". The contents
of the <a> element are the value of the "derivedContent" attribute.
If the "format" attribute has the value "default", and the "target"
attribute points to a <reference> or <referencegroup> element, then
the generated <a> element is surrounded by square brackets in the
output.
<a class="xref" href="#target">Table 2</a>
or
[<a class="xref" href="#RFC1234">RFC1234</a>]
9.67. <svg xmlns='http://www.w3.org/2000/svg'>
This element is rendered as part of the <artwork> element. The
"xmlns='http://www.w3.org/2000/svg'" namespace declaration should be
included, and the SVG should be serialized as well-formed XML, even
for tags that would otherwise not need closing in HTML5.
10. Security Considerations
Since RFCs are sometimes exchanged outside the normal Web sandboxing
mechanism (such as using the "rsync" program to a mirror site) then
loaded from a local file, more care must be taken with the HTML than
is ordinary on the web.
11. References
11.1. Normative References
[BCP14] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997,
<http://www.rfc-editor.org/info/bcp14>.
[RFC2397] Masinter, L., "The "data" URL scheme", RFC 2397,
DOI 10.17487/RFC2397, August 1998,
<http://www.rfc-editor.org/info/rfc2397>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <http://www.rfc-editor.org/info/rfc3629>.
[RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying
Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646,
September 2009, <http://www.rfc-editor.org/info/rfc5646>.
[RFC7322] Flanagan, H. and S. Ginoza, "RFC Style Guide", RFC 7322,
DOI 10.17487/RFC7322, September 2014,
<http://www.rfc-editor.org/info/rfc7322>.
[RFC7991] Hoffman, P., "The "xml2rfc" Version 3 Vocabulary",
RFC 7991, DOI 10.17487/RFC7991, December 2016,
<http://www.rfc-editor.org/info/rfc7991>.
[RFC7993] Flanagan, H., "Cascading Style Sheets (CSS) Requirements
for RFCs", RFC 7993, DOI 10.17487/RFC7993, December 2016,
<http://www.rfc-editor.org/info/rfc7993>.
[W3C.REC-CSS2-20110607]
Bos, B., Celik, T., Hickson, I., and H. Lie, "Cascading
Style Sheets Level 2 Revision 1 (CSS 2.1) Specification",
World Wide Web Consortium Recommendation
REC-CSS2-20110607, June 2011,
<http://www.w3.org/TR/2011/REC-CSS2-20110607>.
[W3C.REC-html5-20141028]
Hickson, I., Berjon, R., Faulkner, S., Leithead, T.,
Navara, E., O'Connor, T., and S. Pfeiffer, "HTML5", World
Wide Web Consortium Recommendation
REC-html5-20141028, October 2014,
<http://www.w3.org/TR/2014/REC-html5-20141028>.
11.2. Informative References
[HCARD] Celik, T., "hCard 1.0", 2015,
<http://microformats.org/wiki/hcard>.
[RFC-STYLE]
RFC Editor, "Style Guide",
<https://www.rfc-editor.org/styleguide/>.
[RFC6949] Flanagan, H. and N. Brownlee, "RFC Series Format
Requirements and Future Development", RFC 6949,
DOI 10.17487/RFC6949, May 2013,
<http://www.rfc-editor.org/info/rfc6949>.
[RFC7990] Flanagan, H., "RFC Format Framework", RFC 7990,
DOI 10.17487/RFC7990, December 2016,
<http://www.rfc-editor.org/info/rfc7990>.
[RFC7998] Hoffman, P. and J. Hildebrand, ""xml2rfc" Version 3
Preparation Tool Description", RFC 7998,
DOI 10.17487/RFC7998, December 2016,
<http://www.rfc-editor.org/info/rfc7998>.
[W3C.WD-css3-page-20130314]
Grant, M., Etemad, E., Lie, H., and S. Sapin, "CSS Paged
Media Module Level 3", World Wide Web Consortium
WD WD-css3-page-20130314, March 2013,
<http://www.w3.org/TR/2013/WD-css3-page-20130314>.
IAB Members at the Time of Approval
The IAB members at the time this memo was approved were (in
alphabetical order):
Jari Arkko
Ralph Droms
Ted Hardie
Joe Hildebrand
Russ Housley
Lee Howard
Erik Nordmark
Robert Sparks
Andrew Sullivan
Dave Thaler
Martin Thomson
Brian Trammell
Suzanne Woolf
Acknowledgments
Heather Flanangan was an early coauthor of this document and helped
its formation. The authors gratefully acknowledge the contributions
of: Patrick Linskey and the members of the RFC Format Design Team
(Nevil Brownlee (ISE), Tony Hansen, Ted Lemon, Julian Reschke, Adam
Roach, Alice Russo, Robert Sparks (Tools Team liaison), and Dave
Thaler).
Authors' Addresses
Joe Hildebrand (editor)
Mozilla
Email: joe-ietf@cursive.net
Paul Hoffman
ICANN
Email: paul.hoffman@icann.org