Internet-Draft | xml2rfc FAQ | February 2019 |
Russo | Expires 23 August 2019 | [Page] |
This is a list of frequently asked questions regarding xml2rfc. Please send questions or corrections to the xml2rfc mailing list.¶
Note: this FAQ is for version 3 of xml2rfc; the vocabulary has been changed significantly from version 2. For guidance on version 2, please see the FAQ for xml2rfc v2. ¶
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. ¶
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/. ¶
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." ¶
This Internet-Draft will expire on 5 August 2019. ¶
Copyright (c) 2019 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. 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. ¶
xml2rfc is a tool that lets you convert an XML source file into a text, HTML, nroff, or expanded XML file. It is available from xml2rfc.ietf.org [xml2rfc] as a web-based service or for download. Version 3 of the tool adds new features and will be used by the RFC Editor to create RFCs. The current version is here: ¶
It's an easy way to create an Internet-Draft in the proper format. It handles boilerplate text and reference text. The HTML and PDF output formats have new features (such as including SVG figures and non-ASCII characters), and the source file can be used for metadata extraction. Also, the RFC Editor will make use of your source file. (For background, see the RFC Format FAQ.) ¶
You need the essentials. XML uses start and end tags, which are nested and matching, and they are case-sensitive. See the section "XML basics" of [Writing I-Ds and RFCs using XML (revised)] for more details. ¶
not yet updated--AR¶
You have several choices when getting started with xml2rfc, such as: ¶
not yet updated--AR¶
Several templates are available from http://tools.ietf.org/tools/templates [templates]. They include templates for a generic draft (e.g., draft-davies-template-bare.xml), as well as for a draft containing a MIB (e.g., mib-doc-template-xml.txt). ¶
not yet updated--AR¶
Sure. We recommend copying the front matter from a template or the XML source of an existing document, then going from there. Put <t> tags around paragraphs, and <figure><artwork> tags around figures. Use <![CDATA[ ... ]]> for blocks of code or figures that contain <. (See What is CDATA for? for more information.) ¶
For references, replace [RFC2119] with <xref target="RFC2119"/>. For cross-references to sections, replace Section 9 with <xref target="sec_cons"/> (if Section 9 has anchor="sec_cons"). See Using References for more information. ¶
rfc
element to create an Internet-Draft?
Use the category
attribute to indicate the intended category of your
draft, where std
is Standards Track, info
is
Informational, exp
is Experimental, bcp
is Best Current
Practice, and historic
is Historic.
¶
Use the submissionType
attribute to indicate the intended
document stream, where the value can be IETF
, IAB
,
IRTF
, or independent
.¶
See Section A.1 of [RFC7991]¶
Use the docName attribute to indicate the filename. ¶
If the document potentially updates or obsoletes any RFCs, use the updates and obsoletes attributes to indicate the relevant RFC numbers. For Internet-Drafts, this information will be displayed in the header, followed by "(if approved)". ¶
For example, putting it together: ¶
<rfc category="info" submissionType="IETF" ipr="trust200902" docName="draft-ietf-wgname-topic-00" updates="1234, 1235" obsoletes="1236" sortRefs="true">¶
Note: The attributes number and seriesNo will be added by the RFC Editor if your draft is approved for publication as an RFC. ¶
Note: Some features that used to be processing instructions (in v2)
are now attributes of the rfc element (in v3) -- for
example, sortRefs
and symRefs
.
¶
not yet updated--AR¶
At the top, if there is the PI <?rfc strict="yes"?>, then xml2rfc is trying to enforce I-D nits and DTD validity. ¶
If you are getting "This file does not begin with an XML declaration", have you entered the filename correctly? It can indicate a problem with the first line (<?xml version="1.0">) or it can mean "File not found". Also, check the permissions on the file. ¶
One common error is caused by mismatched tags. For example, when there is a missing </t>, the error might appear as follows: ¶
end tag "section" does not match open element "t" around line 65¶
Using Bill's xml2rfc validator can provide more precise error messages. ¶
not yet updated--AR¶
A set of online citation libraries are maintained on xml2rfc.ietf.org [xml2rfc]. They include citations for RFCs, Internet-Drafts, and documents produced by the W3C and 3GPP, among others. ¶
To make use of the citation libraries, there are 2 methods: ¶
define an ENTITY at the top: ¶
<!ENTITY RFC2119 SYSTEM "https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml">¶
and use &RFC2119; in the references section ¶
use an include in the references section ¶
<?rfc include="reference.RFC.2119.xml"?>¶
For an Internet-Draft, the citation file uses the draft string. For example: ¶
<?rfc include="reference.I-D.ietf-wgname-topic.xml"?>¶
Preferably, use the citation libraries when possible. However, another option is to include the complete reference element (see Section 3.2). Here's a template of a reference element: ¶
<reference anchor="" target=""> <front> <title></title> <author initials="" surname="" fullname=""> <organization /> </author> <date month="" year="" /> </front> <seriesInfo name="" value="" /> </reference>¶
All are cited textually in the same manner -- by using xref elements where the target corresponds to the anchor of the reference element, e.g., <xref target="RFC2119" />. The anchors for RFCs are "RFCNNNN" (4 digits, using leading zeros) and the anchors for Internet-Drafts are "I-D.<name without "draft-ietf-" or the version number>". ¶
There are several ways to insert the full reference element from the citation library: ¶
In the rfc
element, set the attribute symRefs="yes"
for
symbolic references. This makes reference tags be the same as the anchor
(e.g., [RFC2119]), instead of numerical (e.g., [1]).
¶
symrefs="yes" is the default, starting with v1.33 of xml2rfc. ¶
Use the displayreference
element and set the to
attribute to
the nickname. Tip: place it before the references
element. For example:
¶
<displayreference target="RFC7296" to="IKEv2"/> <references> [...] <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7296.xml"/>¶
yields: ¶
In the rfc element, set the attribute sortRefs="yes"
. Note that sortRefs only has an effect if symRefs="yes"
.
¶
The eref element for an external reference creates a link in the HTML output. For example: ¶
<eref target="https://www.w3.org">¶
yields https://www.w3.org.¶
<eref target="http://www.w3.org">W3C Home Page</eref>¶
yields W3C Home Page.¶
Another option is using xref and creating a reference that uses the target attribute for the URL. For example: ¶
<reference anchor="W3C" target="https://www.w3.org/"> <front> <title>World Wide Web Consortium (W3C)</title> <author/> </front> </reference>¶
yields ¶
[W3C] "World Wide Web Consortium (W3C)", <https://www.w3.org/>.¶
Use the name element (child of the references element) as follows: ¶
<back> <references> <name>Normative References</name> ... </references> <references> <name>Informative References</name> ... </references> </back>¶
not yet updated--AR¶
Make sure the section you want to reference has an anchor attribute. For example: ¶
<section title="Security Considerations" anchor="sec_cons">¶
Then, refer to it with an xref element: ¶
See <xref target="sec_cons" />.¶
which yields the text output: ¶
See Section 9.¶
(where the number of that section is determined dynamically). ¶
not fully updated--AR¶
Use relref. Examples below are from draft-v3-features. Set displayFormat to various options. ¶
"of": See Section 1 of [RFC7991]¶
"comma": See [RFC7991], Section 2.2¶
"parens": See [RFC7991] (Section A)¶
(default): See Section 1 of [RFC7991]¶
With text content: See Section 2 of [the wonderful Section 2 of RFC 7991]¶
Use the format attribute. For example, assuming the anchor attributes for the relevant sections have the values "sec_cons" and "IANA_cons": ¶
See Sections <xref target="sec_cons" format="counter" /> and <xref target="IANA_cons" format="counter" />.¶
yields the text output: ¶
See Sections 9 and 10.¶
Note: The format attribute can have the value "title", which displays the title of the section. For example, ¶
See the <xref target="sec_cons" format="title" />.¶
yields the text output: ¶
See the Security Considerations.¶
For bulleted lists, use the <ul> element. ¶
For an empty list (indentation only), use the <ul> element with
empty="true"
.
¶
For definition lists (a.k.a. hanging lists in xml2rfc v2), use the <dl> element. See Section 4.4. ¶
For numbers or letters, use the type attribute of the <ol> element; examples below. ¶
For full details, see Section 2.34.5 of [RFC7991]¶
(1) (2) is <ol type="(%d)"> (3) (a) (b) is <ol type="(%c)"> (c) REQ1: REQ2: is <ol type="REQ%d:"> REQ3:¶
Set the group attribute of the <ol> element. For example:¶
Here is some text in between.¶
Use a <dl> element (definition list), where each <dt> (term) in has a corresponding <dd> (description). ¶
For example:¶
<dl> <dt>Unassigned:</dt> <dd>Unused and available for assignment via documented procedures.</dd> <dt>Reserved:</dt> <dd>Not to be assigned. Reserved values are held for special uses, such as to extend the namespace when it become exhausted. Reserved values are not available for general assignment.</dd> </dl>¶
yields:¶
Note: The appearance is slightly different in the text output.¶
Use newline="true"
to get a line
break after the term. For example:¶
<dl newline="true"> <dt>Unassigned:</dt> <dd>Unused and available for assignment via documented procedures.</dd> <dt>Reserved:</dt> <dd>Not to be assigned. Reserved values are held for special uses, such as to extend the namespace when it become exhausted. Reserved values are not available for general assignment.</dd> </dl>¶
yields:¶
A CDATA block is left alone by xml2rfc. It does not try to parse XML inside of a CDATA block. (For example, if a figure contains "<", you don't have to use <) So it is especially good for when there are XML examples in the document. ¶
not yet updated--AR¶
Remove the anchor attribute for that figure. Figure elements without anchor attributes will not be automatically numbered (i.e., "Figure 1"). ¶
To prevent these characters from being parsed as XML, use ¶
& for & < for < > for >¶
In addition, the following entities are defined: ¶
' for ' " for " for non-breaking space &nbhy; for non-breaking hyphen¶
Insert (non-breaking space) between words that you want to keep together on a line. ¶
Use the role attribute of the author element. For example: ¶
<author initials="J" surname="Doe" fullname="John Doe" role="editor">¶
You can use comments <!-- --> or <cref> elements. Comments are only visible in the XML source file. ¶
Example of using comments: ¶
<!-- [JD] This point needs revision.-->¶
<cref> will show up in the output when the attribute display="true" (which is the default). ¶
Example of using <cref>: ¶
<cref anchor="Q1" source="JD">This point needs revision.</cref>¶
yields ¶
[[This point needs revision.--JD]]¶
xml2rfc validates it. Also, you can run rfclint: https://pypi.org/project/rfclint/. ¶
not yet updated--AR¶
Yes, rfc2629.xslt by Julian Reschke provides a different kind of HTML output than the HTML output mode of xml2rfc. It is available for download from http://greenbytes.de/tech/webdav/rfc2629xslt.zip. See "Transforming RFC2629-formatted XML through XSLT" for more information. ¶
Yes, id2xml is available here: https://pypi.org/project/id2xml/. It is available as a web service on https://xml2rfc.ietf.org/. ¶
On the command line: xml2rfc --v2v3 inputfile.xml
¶
Using the web service (https://xml2rfc.tools.ietf.org/experimental.html), select "Output format: convert v2 to v3 XML". ¶
Some highlights are including UTF-8 characters, text formatting, and SVG diagrams. For complete details, see Section 1.3 of [RFC7991]¶
With encoding="utf-8"
in your XML file, you can insert the
characters directly into the file in the following locations:
¶
Each of these elements has an ascii
attribute to hold
the ASCII equivalent, which will also appear in the output format. For
the author element, the attributes are named asciiFullname,
asciiInitials, andasciiSurnames.¶
For example:¶
<table anchor="table_ex"> <name>IETF Meetings in 2005</name> <thead> <tr> <th align='center'>IETF #</th> <th align='center'>City</th> <th align='center'># of Attendees</th> </tr> </thead> <tbody> <tr> <td align="center">62</td> <td align="center">Minneapolis</td> <td align="center">1133</td> </tr> <tr> <td align="center">63</td> <td align="center">Paris</td> <td align="center">1450</td> </tr> <tr> <td align="center">64</td> <td align="center">Vancouver</td> <td align="center">1240</td> </tr> </tbody> </table>¶
yields:¶
IETF # | City | # of Attendees |
---|---|---|
62 | Minneapolis | 1133 |
63 | Paris | 1450 |
64 | Vancouver | 1240 |
Data from https://www.ietf.org/how/meetings/past/. ¶
For full details, see Section 2.54 of [RFC7991]¶
You can check your SVG file against the SVG Tiny 1.2
spec on the experimental page
(https://xml2rfc.tools.ietf.org/experimental.html),
and a script called svgcheck
is available here: https://pypi.org/project/svgcheck/.¶
For more information, see [RFC7996] and Tips on creating SVG files. ¶
There are at least five ways to include SVG in artwork in Internet-Drafts: ¶
- Inline, by including all of the SVG in the content of the element, such as: <artwork type="svg"><svg xmlns="http://www.w3.org/2000/ svg..."> ¶
- Inline, but using XInclude (see Appendix B.1), such as: <artwork type="svg"><xi:include href=...> ¶
- As a data: URI, such as: <artwork type="svg" src="data:image/ svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3..."> ¶
- As a URI to an external entity, such as: <artwork type="svg" src="http://www.example.com/..."> ¶
- As a local file, such as: <artwork type="svg" src="diagram12.svg"> ¶
Use <sub> for subscript, and <sup> for superscript.¶
Example (from RFC 6330):¶
abnf, asn.1, bash, c++, c, cbor, dtd, java, javascript, json, mib,
perl, pseudocode, python, rnc, xml,
and yang.
¶
Ths list is subject to change; for details, see Section 2.48.4 of [RFC7991]¶
It is not a MUST, but it makes the usage more clear.¶
SHOULD without the <bcp14> element, SHOULD with it.¶
Print the PDF.¶
The source files of RFCs have changed over time. Most RFCs have NROFF source files; sometimes an XML file has been archived. You can request an XML source file directly from rfc-editor@rfc-editor.org. After RFC TBD, the XML files will be available for download https://www.rfc-editor.org/retrieve/bulk. ¶
This FAQ was made possible by the tools, documentation, and test files created by Henrik Levkowetz, Julian Reschke, and Sandy Ginoza. ¶