Network Working Group R. Tse Internet-Draft N. Nicholas Intended status: Informational J. Lau Expires: May 24, 2018 P. Brasolin Ribose November 20, 2017 Writing Internet-Drafts And RFCs In AsciiDoc (AsciiRFC) draft-ribose-asciirfc-00 Abstract This document describes the AsciiDoc syntax extension called AsciiRFC designed for authoring IETF Internet-Drafts and RFCs. AsciiDoc is a human readable document markup language which affords more granular control over markup than comparable schemes such as Markdown. The AsciiRFC syntax is designed to allow the author to entirely focus on text, providing the full power of the resulting XML RFC through the AsciiDoc language, while abstracting away the need to manually edit XML, including references. This document itself was written and generated into XML RFC v2 (RFC7749) and XML RFC v3 (RFC7991) directly through asciidoctor-rfc, an AsciiRFC generator. Status of This Memo 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 May 24, 2018. Tse, et al. Expires May 24, 2018 [Page 1] Internet-Draft AsciiRFC Specifications November 2017 Copyright Notice Copyright (c) 2017 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions Used in This Document . . . . . . . . . . . . . . 4 2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4 3. Document Structure And AsciiDoctor Syntax . . . . . . . . . . 4 4. Header And Document Attributes . . . . . . . . . . . . . . . 6 5. Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6. Sections and Paragraphs . . . . . . . . . . . . . . . . . . . 11 7. Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8. Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 9. Blockquotes . . . . . . . . . . . . . . . . . . . . . . . . . 15 10. Notes And Asides . . . . . . . . . . . . . . . . . . . . . . 16 11. Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 12. Inline Formatting . . . . . . . . . . . . . . . . . . . . . . 20 13. Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 14. Crossreferences . . . . . . . . . . . . . . . . . . . . . . . 21 15. Inclusions . . . . . . . . . . . . . . . . . . . . . . . . . 23 16. Encoding and Entities . . . . . . . . . . . . . . . . . . . . 23 17. Bibliography . . . . . . . . . . . . . . . . . . . . . . . . 23 17.1. Using Raw RFC XML . . . . . . . . . . . . . . . . . . . 24 17.2. Using preprocessing . . . . . . . . . . . . . . . . . . 25 18. RFC XML features not supported in Asciidoctor . . . . . . . . 27 19. Authoring . . . . . . . . . . . . . . . . . . . . . . . . . . 27 20. Security Considerations . . . . . . . . . . . . . . . . . . . 28 21. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28 22. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 29 22.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . . 29 23. References . . . . . . . . . . . . . . . . . . . . . . . . . 29 23.1. Normative References . . . . . . . . . . . . . . . . . . 29 23.2. Informative References . . . . . . . . . . . . . . . . . 29 23.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 30 Tse, et al. Expires May 24, 2018 [Page 2] Internet-Draft AsciiRFC Specifications November 2017 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30 1. Introduction As specified in [RFC7990], the IETF intends for the canonical format of RFCs to transition from plain-text ASCII to RFC XML v3 [RFC7991]. While plain-text will continue to be accepted from authors by the IETF, at least in the short- to medium-term, XML will be preferred for submission, and any plain-text submissions will need to be converted to RFC XML v3. The transition to RFC XML v3 places added onus on authors to generate compliant XML. This need is already met for RFC XML v2 [RFC7749] by tools such as MMark [1] and Kramdown [2], both based on the popular Markdown markup language [3] [RFC7763] [RFC7764]. Asciidoctor [4] is an alternative markup language to Markdown, with features that make it attractive as a markup language for RFC with XML output. Compared to Markdown [5], o Asciidoctor was designed from the beginning as a publishing language: it was initially intended as a plain-text alternative to the DocBook XML schema. For that reason, Asciidoctor natively supports the full range of formatting required by RFC XML (including notes, tables, bibliographies, source-code blocks, and definition lists), without resorting to embedded HTML or Markdown "flavours". o Asciidoctor is extensible, with a well-defined API. o Asciidoctor allows granular control of rendering, including user- specified attribute of text blocks. o Asciidoctor allows document inclusion, for managing large-scale documentation projects. o Asciidoctor allows granular control of permutations of block nesting, such as source code within lists or definition lists within unordered lists. o As a more formal counterpart to Markdown, Asciidoctor is well- suited to generating XML that needs to conform to a specified schema. Section 1.2 of [RFC7764] famously states that "there is no such thing as "invalid" Markdown, there is no standard demanding adherence to Tse, et al. Expires May 24, 2018 [Page 3] Internet-Draft AsciiRFC Specifications November 2017 the Markdown syntax, and there is no governing body that guides or impedes its development." While there are contexts where that lack of rigour is helpful, the authoring of RFCs does have a standard and a governing body, and there is such a thing as invalid RFC XML. A more rigorous counterpart to Markdown, which still preserves its basic approach to formatting, is useful in generating RFC XML that encompasses a fuller subset of the specification, and preempting malformed RFC XML output. As with Markdown, there is a wide range of tools that can render Asciidoctor; so Asciidoctor drafts of RFC documents can be previewed and accessed without depending on the RFC tools ecosystem. Our porting of RFC XML to Asciidoctor has aimed to ensure that, as much as possible, the Asciidoctor being used for RFC is generic Asciidoctor, which can be processed by Asciidoctor tools in general. (The only exception to this as an add-on is the optional bibliography module, which allows bibliographies to be assembled on the fly based on citations in a document.) 2. Conventions Used in This Document The key words "*MUST*", "*MUST NOT*", "*REQUIRED*", "*SHALL*", "*SHALL NOT*", "*SHOULD*", "*SHOULD NOT*", "*RECOMMENDED*", "*MAY*", and "*OPTIONAL*" in this document are to be interpreted as described in [RFC2119]. 2.1. Definitions TODO. 3. Document Structure And AsciiDoctor Syntax The syntax of Asciidoctor is presented in the Asciidoctor user manual [6]. Asciidoctor consists of: o A document header, containing a title, a list of authors, and document attributes in lines prefixed with ":" o An optional document preamble, separated from document header by a blank line o A number of sections, set off by a section title (a line prefixed with two or more "=". A section may contain: * Other sections, whose level of nesting is indicated by the number of "=" in their header Tse, et al. Expires May 24, 2018 [Page 4] Internet-Draft AsciiRFC Specifications November 2017 * Blocks of text. Blocks can have metadata (including a title, an anchor for cross-references, and attributes.) Blocks can be: + Paragraphs, which are terminated by blank lines. + Lists. List items are by default paragraphs, but can span over multiple paragraphs. + Delimited blocks (with a line delimiter on either side of them); these include tables, notes, sidebars, source code, block quotes, examples, and unprocessed content (e.g. raw XML). Delimited blocks contain by default one or more paragraphs. + List items can contain other blocks, including both nested lists and delimited blocks. + Some delimited blocks can contain other delimited blocks; for example, examples can contain source code as well as discussion in paragraphs. * Blocks of text consist of inline text, which themselves can contain markup. Inline markup includes: o Text formatting: bold, italic, superscript, subscript, monospace o Custom markup macros o URLs, including display text o Inline anchors o Cross-references to anchors (IDs of blocks or spans of text), including display text o Images, audio, and visual files o Index terms o Equations (native support for AsciiMathML [7] and TeX/LaTeX [8], via the MathJax [9] tool o Footnotes Tse, et al. Expires May 24, 2018 [Page 5] Internet-Draft AsciiRFC Specifications November 2017 The Asciidoctor document structure aligns with the RFC XML v2 and v3 structure. In the following, v3 equivalences are given: o Header: "" attributes, most "front" elements o Preamble: "front/abstract" and "front/note" o Sections: "middle/section" elements o Sections with "bibliography" style attributes: "back/references" elements. o Sections with "appendix" style attributes: "back/section" elements. o Paragraphs: "t" elements o Lists: "ul", "ol", "dl" elements o Delimited blocks: "artwork", "aside", "blockquote", "figure", "note", "sourcecode", "table" o Inline markup: "bcp14", "br", "cref", "em", "eref", "iref", "relref", "strong", "sub", "sup", "tt", "xref" Full details of the mapping of Asciidoctor elements to RFC XML v2 and v3 elements, and of how to convert Asciidoctor documents to RFC XML, are given in . The following gives an overview of how to create an RFC XML document in Asciidoctor, with some pitfalls to be aware of. Illustrations are in RFC XML v3, although the converter deals with both versions of RFC XML. 4. Header And Document Attributes The header gives the document title, followed by an optional author attribution, and a series of document attributes, with no carriage return breaks. For example: Tse, et al. Expires May 24, 2018 [Page 6] Internet-Draft AsciiRFC Specifications November 2017 = Transmission of IP Datagrams on Avian Carriers David Waitzman :doctype: internet-draft :abbrev: IP Datagrams on Avian Carriers :obsoletes: 10, 120 :updates: 2010, 2120 :status: informational :name: internet-draft-avian-transmission-00 :ipr: trust200902 :area: Internet :workgroup: Network Working Group :keyword: avians, datagrams :revdate: 1990-04-01T00:00:00Z :organization: BBN STC :phone: (617) 873-4323 :uri: http://bbn.com :street: 10 Moulton Street :city: Cambridge :code: MA 02238 :rfcedstyle: yes :text-list-symbols: yes :rfc2629xslt: true The document attributes are used to populate "rfc" attributes, "front" elements, and document-level processing instructions. o ":doctype:" determines whether the document will be considered "rfc" or "internet-draft", and interprets other attributes accordingly. o Certain attributes ("workgroup", "area", "keyword") are comma delimited, and result in repeated RFC XML elements. o A few attributes are specific to the operation of the RFC XML document converter: * ":no-rfc-bold-bcp14: false" overrides the conversion of boldface uppercase BCP14 [RFC2119] words with the "bcp14" element. * ":smart-quotes false:" overrides Asciidoctor's conversion of straight quotes and apostrophes to smart quotes and apostrophes. * ":inline-definition-lists: true" overrides the RFC XML v2 "idnits" requirement that a blank line be inserted between a definition list term and its definition. Tse, et al. Expires May 24, 2018 [Page 7] Internet-Draft AsciiRFC Specifications November 2017 The foregoing Asciidoc renders into RFC XML v3 as: A Standard for the Transmission of IP Datagrams on Avian Carriers BBN STC
10 Moulton Street Cambridge MA 02238 (617) 873-4323 dwaitzman@BBN.COM http://bbn.com
Internet Network Working Group avians datagrams Details of a second, third etc. author, including their organization and contact details, are provided by suffixing the author attribute with "_2", "_3" etc.: Tse, et al. Expires May 24, 2018 [Page 8] Internet-Draft AsciiRFC Specifications November 2017 John Doe Horton ; Billy Bob Thornton :fullname: John Doe Horton :lastname: Horton :forename_initials: J. D. :role: editor :organization: Ribose :fax: 555 5555 :email: john.doe@email.com :uri: http://example.com :phone: 555 5655 :street: 57 Mt Pleasant St :city: Dullsville :region: NSW :country: Australia :code: 3333 :fullname_2: Billy Bob Thornton :lastname_2: Thornton :forename_initials_2: B. B. :role_2: editor :organization_2: IBM :fax_2: 555 6666 :email_2: billy.thornton@email.com :uri_2: http://ibm.com :phone_2: 555 6655 :street_2: 67 Mt Pleasant St :city_2: Dulltown :region_2: VIC :country_2: UK :code_2: 44444 The initial author attribution in Asciidoctor, e.g. "John Doe Horton; Billy Bob Thornton " in the example above, expects a strict format of First Name, zero or more Middle Names, Last name, and cannot process honorifics like "Dr" or suffixes like "Jr". Name attributes with any degree of complexity should be overriden by using the ":fullname:" and ":lastname:" attributes. The ":forename_initials:" replaces the built-in ":initials:" attribute (which includes the surname initial), and is not automatically populated from the name attribution. 5. Preamble The preamble in Asciidoctor is the text between the end of the document header (which terminates with a blank line) and the first section of text. Any paragraphs of text in the preamble are treated as an abstract, and may optionally be tagged with the "abstract" Tse, et al. Expires May 24, 2018 [Page 9] Internet-Draft AsciiRFC Specifications November 2017 style attribute. Any notes in the preamble are treated as a "note" element. For example: = A Standard for the Transmission of IP Datagrams on Avian Carriers David Waitzman :doctype: internet-draft :abbrev: IP Datagrams on Avian Carriers :status: informational :name: internet-draft-avian-transmission-00 Preamble content. More Preamble content. NOTE: This is a note. [NOTE] .Title of Note ==== This is another note. ==== A Standard for the Transmission of IP Datagrams on Avian Carriers
dwaitzman@BBN.COM
Preamble content. More Preamble content. This is a note. Title of Note This is another note.
Tse, et al. Expires May 24, 2018 [Page 10] Internet-Draft AsciiRFC Specifications November 2017 6. Sections and Paragraphs Section headers are given with a sequence of "=", the number of "=" giving the header level. Section numbering is toggled with the in- document attribute ":sectnums:" (on), ":sectnums!:" (off) :sectnums: [toc=exclude] == Section 1 Para 1 === Subsection 1.1 Para 1a :sectnums!: [toc=default] === Subsection 1.2 Para 2 ==== Subsection 1.2.1 Para 3
Section 1 Para 1
Subsection 1.1 Para 1a
Subsection 1.2 Para 2
Subsection 1.2.1 Para 3
7. Figures AsciiDoc Examples (corresponding to RFC XML figures), source code listings, and literals (preformatted text) are all delimited blocks. Listings and literals can occur nested within examples. If an Asciidoctor listing or literal occurs outside of an example, the RFC XML converter will supply the surrounding figure element: Tse, et al. Expires May 24, 2018 [Page 11] Internet-Draft AsciiRFC Specifications November 2017 .Figure 1 ==== .figure1.txt .... Figures are only permitted to contain listings (sourcecode), images (artwork), or literal (artwork) .... [source,ruby] ---- def listing(node) result = [] if node.parent.context != :example result << "
" end end ---- ====
Figure 1 Figures are only permitted to contain listings (sourcecode), images (artwork), or literal (artwork) def listing(node) result = [] if node.parent.context != :example result << "<figure>" end end
8. Lists Asciidoctor supports ordered, unordered, and definition lists. Indentation of ordered and unordered lists is indicated by repeating the list item prefix ("*" and "." respectively.) List attributes specify the type of symbol used for ordered lists: Tse, et al. Expires May 24, 2018 [Page 12] Internet-Draft AsciiRFC Specifications November 2017 [loweralpha] . First . Second [upperalpha] .. Third .. Fourth . Fifth . Sixth
  1. First
  2. Second
    1. Third
    2. Fourth
  3. Fifth
  4. Sixth
A list item by default spans a single paragraph. A following paragraph or other block element can be appended to the current list item by prefixing it with "+" in a separate line (Asciidoc list continuation [10].) Notes:: Note 1. + Note 2. + Note 3.
Notes
Note 1. Note 2. Note 3.
List continuations can also be embed to populate a list item with a sequence of blocks as a unit (in an Asciidoc open block): Tse, et al. Expires May 24, 2018 [Page 13] Internet-Draft AsciiRFC Specifications November 2017 * List Entry 1 * List Entry 2 + -- Note 2. .... Literal .... Note 3. --
  • List Entry 1
  • List Entry 2 Note 2.
    Literal
    Note 3.
Asciidoctor considers paragraphs to be the basic level of blocks, and does not permit lists to be nested within them: text after a list is considered to be a new paragraph. So markup like the following cannot be generated via Asciidoctor: Tse, et al. Expires May 24, 2018 [Page 14] Internet-Draft AsciiRFC Specifications November 2017 This is the start of a paragraph.
  • List Entry 1
  • List Entry 2 Note 2.
    Literal
    Note 3.
9. Blockquotes Asciidoctor supports blockquotes and quotations of verse; its block quotations permit arbitrary levels of quote nesting. RFC XML v3 only supports one level of blockquotes. RFC XML v3 does not support line breaks outside of tables, so verse quotations are converted to prose. [quote,attribution="Monty Python",citetitle="http://foo.bar"] ____ Dennis: Come and see the violence inherent in the system. Help! Help! I'm being repressed! King Arthur: Bloody peasant! Dennis: Oh, what a giveaway! * Did you hear that? * Did you hear that, eh? * That's what I'm on about! ** Did you see him repressing me? ** You saw him, Didn't you? ____ Tse, et al. Expires May 24, 2018 [Page 15] Internet-Draft AsciiRFC Specifications November 2017
Dennis: Come and see the violence inherent in the system. Help! Help! I’m being repressed! King Arthur: Bloody peasant! Dennis: Oh, what a giveaway!
  • Did you hear that?
  • Did you hear that, eh?
  • That’s what I’m on about!
    • Did you see him repressing me?
    • You saw him, Didn’t you?
10. Notes And Asides Asciidoctor supports a range of "admonitions", including notes, warnings, and tips. They are indicated by a paragraph prefix (e.g. "WARNING:"), or as a block with an admonition style attribute. All admonitions are converted to "note" elements in the document preamble, and "cref" documents in the main document. RFC XML v3 also supports asides (Asciidoctor sidebars): == Section 1 [NOTE,source=GBS] .Note Title ==== Any admonition inside the body of the text is a comment. ==== **** Sidebar Another sidebar * This is a list .... And this is ascii-art .... **** Tse, et al. Expires May 24, 2018 [Page 16] Internet-Draft AsciiRFC Specifications November 2017
Section 1 Any admonition inside the body of the text is a comment. Note that no inline formatting is permitted in RFC XML v2, and it is stripped for v2 by the converter. Because paragraphs in Asciidoctor cannot contain any other blocks, a comment at the end of a paragraph is treated as a new block. In the document converter, any such comments are moved inside the preceding RFC XML paragraph; if the comment is at the start of a section, as in the example above, it is wrapped inside a paragraph. While Asciidoctor has comments proper, notated with initial "//", they are ignore by the document converter, so they will not appear as XML comments in the converter output. 11. Tables Asciidoctor tables, like RFC XML v3, support distinct table heads, bodies and feet, cells spanning multiple rows and columns, and horizontal alignment. The larger range of formatting options available in RFC XML v2 is also supported. Tse, et al. Expires May 24, 2018 [Page 17] Internet-Draft AsciiRFC Specifications November 2017 .Table Title |=== |head | head h|header cell | body cell | | body cell 2+| colspan of 2 .2+|rowspan of 2 | cell |cell ^|centre aligned cell | cell <|left aligned cell | cell >|right aligned cell | cell |foot | foot |=== Tse, et al. Expires May 24, 2018 [Page 18] Internet-Draft AsciiRFC Specifications November 2017 Table Title
head head
header cell body cell
body cell
colspan of 2
rowspan of 2 cell
cell
centre aligned cell cell
left aligned cell cell
right aligned cell cell
foot foot
Tse, et al. Expires May 24, 2018 [Page 19] Internet-Draft AsciiRFC Specifications November 2017 Neither version of RFC XML is as expressive in its table structure as Asciidoctor; RFC XML for example does not permit blocks within table cells. 12. Inline Formatting Like RFC XML v3, Asciidoctor supports italics, boldface, monospace, subscripts and superscripts: _Text_ *Text* `Text` ^Superscript^ ~Subscript~ Text Text Text Superscript Subscript RFC XML v3 also supports tagging of BCP14 keywords [RFC2119]; this is done in Asciidoctor either by tagging them with a custom formatting span ("bcp14#mustnot#"), or by converting by default BCP14 boldface all-caps words: This [bcp14]#must not# stand This *MUST NOT* stand This MUST NOT stand This MUST NOT stand Any spans of BCP14 text delimited by inline formatting delimiters needs to be contained within a single line of text; the Asciidoctor API breaks up formatting spans across line breaks. Formatting delimiters like "*" can be escaped with backslash; double formatting delimiters, like "" and "__", need to be escaped with double backslash("\\"). Escaping delimiters is not always reliable, and for double delimiters it is preferable to use HTML entities ("**"), or attribute references: :dblast: ** `{dblast}` 13. Links Common URL formats are recognised automatically as hyperlinks, and are rendered as such; any hyperlinked text is appended after the hyperlink in square brackets: Tse, et al. Expires May 24, 2018 [Page 20] Internet-Draft AsciiRFC Specifications November 2017 http://example.com/[linktext] linktext To prevent hyperlinking of a URL, prefix it with a backslash. 14. Crossreferences Anchors for crossreferences are notated as "[[...]]" or "[#...]". Anchors can be inserted on their own line in front of most blocks. Asciidoctor supports anchors in a much wider range of contexts than is supported than RFC XML v3 (let alone v2); anchors that are not supported for that version of RFC XML are simply ignored by the converter. Note that anchors in RFC XML are constrained to the format "[A-Za-z_:][[A-Za-z0-9_:.-]*". Cross-references to anchors are notated as "<""..."">"; cross- references with custom text as "<""reference,text"">". Asciidoctor does not otherwise support attributes on cross-references, but the converter extracts format information from templated text within cross-references: "format=x:text" populates the "xref@format" attribute, while a section number followed by one of the words "of, parens, bare, text" is treated as a "relref" reference to an external document. [[crossreference]] == Section 1 == Section 2 See <>. == Section 3 See <> == Section 4 See <> == Section 5 See <> See <> <> <> <>
Section 1
Tse, et al. Expires May 24, 2018 [Page 21] Internet-Draft AsciiRFC Specifications November 2017
Section 2 See .
Section 3 See text
Section 4 See text
Section 5 See See text text Tse, et al. Expires May 24, 2018 [Page 22] Internet-Draft AsciiRFC Specifications November 2017
15. Inclusions The Asciidoctor "include" directive [11] is used to include external files in a master Asciidoctor document. The directive is capable of sophisticated document merging, including adjusting the heading levels of the included text, selecting text within specified tags or line numbers to be included, and adjusting the indentation of code snippets in merged text: \include::path[ leveloffset=_offset_, lines=_ranges_, tag(s)=_name(s)_, indent=_depth_ ] 16. Encoding and Entities XML accepted the full range of characters in the world's languages through UTF-8 character encoding, and one of the motivations for the move from plain text to RFC XML has been to allow non-ASCII characters to be included in RFCs. However, current RFC XML v2 tools still do not support UTF-8, and other tool support for UTF-8 also remains patchy. Out of an abundance of caution, the RFC XML converter uses US-ASCII for its character encoding, and renders any non-ASCII characters as entities. The converter accepts HTML entities in Asciidoctor, even though they are not part of the XML specification; HTML entities such as " " feature in examples of RFC XML provided by the IETF. In order to prevent dependence of the XML output from extraneous entity definitions, any such entities are rendered in the XML as decimal character entities. 17. Bibliography Asciidoctor has a simple encoding of bibliographies, but it is not adequate for the complexity of bibliographic markup supported in RFC XML. RFC documents overwhelmingly cite other RFC documents, and canonical RFC XML bibliographic entries are available at ; so it would be inefficient to encode those entries in Asciidoctor, only to have them converted back to RFC XML. Tse, et al. Expires May 24, 2018 [Page 23] Internet-Draft AsciiRFC Specifications November 2017 The converter provides two means of incorporating bibliographies into RFC documents authored in Asciidoctor: o using raw RFC XML; and o assembling bibliographies in preprocessing. In either case, the RFC XML needs to be well-formed; missing closing tags can lead to erratic behaviour in the converter. 17.1. Using Raw RFC XML In the first, bibliographic citations are handled like all other cross-references. The bibliographic entries for normative and informative references are given in the Asciidoctor as passthrough blocks, which contain the raw RFC XML for all references; document conversion leaves the raw RFC XML in place. This approach requires authors to maintain the normative and informative bibliographies within the document, to update them as citations are added and removed, and to sort them manually. Some datagram padding may be needed.<> [bibliography] == Normative References ++++ Guidelines for Writing an IANA Considerations Section in RFCs Sacramento State UC Davis ++++ Tse, et al. Expires May 24, 2018 [Page 24] Internet-Draft AsciiRFC Specifications November 2017 Some datagram padding may be needed Normative References Guidelines for Writing an IANA Considerations Section in RFCs Sacramento State UC Davis 17.2. Using preprocessing The alternative method is to use a preprocessing tool, asciidoc- bibliography [12], to import citations into the Asciidoctor document from an external file of references. The references file consists of RFC XML reference entries, and still needs to be managed manually; however the bibliographies are assembled from that file, sorted, and inserted into the normative and informative references in preprocessing. Citations in the document itself are given as macros to be interpreted by the preprocessor; this allows them to be split into normative and informative references. (The MMark tool likewise splits reference citations into normative and informative.) Integration with the asciidoc-bibliography gem proceeds as follows: 1. Create an RFC XML references file, consisting of a "" element with individual "" elements inserted, as would be done for the informative and normative references normally. The references file will contain all possible references to be used in the file; the bibliography gem will select which references have actually been cited in the document. A. Rather than hand crafting RFC XML references for RFC documents, you should download them from an authoritative Tse, et al. Expires May 24, 2018 [Page 25] Internet-Draft AsciiRFC Specifications November 2017 source; e.g. B. Unlike the case for RFC XML documents created manually, the references file does not recognise XML entities and will not attempt to download them during processing. Any references to will need to be downloaded and inserted into the references file. C. The RFC XML in the references file will need to be appropriate to the version of RFC XML used in the main document, as usual. Note that RFC XML v2 references are forward compatible with v3; v3 contains a couple of additional elements. 2. Add to the main document header attributes referencing the references file (":bibliography-database:"), and the bibliography style (":bibliography-style:rfc-v3"). 3. References to a normative reference are inserted with the macro "cite:norm[id]" instead of "<""id"">", where "id" is the anchor of the reference. 4. References to an infomrative reference are inserted with the macro "cite:info[id]" instead of "<""id"">", where "id" is the anchor of the reference. 5. Normative and Informative References are inserted in the document through a macro, which occurs where the RFC XML references would be inserted: [bibliography] == Normative References ++++ bibliography::norm[] ++++ [bibliography] == Informative References ++++ bibliography::info[] ++++ Tse, et al. Expires May 24, 2018 [Page 26] Internet-Draft AsciiRFC Specifications November 2017 18. RFC XML features not supported in Asciidoctor The following features of RFC XML are not supported by the Asciidoctor converter, and would need to be adjusted manually: +----------------------------+-----------------------+--------------+ | RFC XML element | RFC XML v3 | RFC XML v2 | +----------------------------+-----------------------+--------------+ | "front/boilerplate" | Not added by the | N/A | | | converter | | | "iref@primary" | N | N | | "reference" (and all | As Raw XML | As Raw XML | | children) | | | | "table/preamble" | Deprecated | N | | "table/postamble" | Deprecated | N | | "artwork@width" | Only on images | Only on | | | | images | | "artwork@height" | Only on images | Only on | | | | images | +----------------------------+-----------------------+--------------+ 19. Authoring To author an Asciidoctor RFC document, you should familiarise yourself with the Asciidoctor specification [13]. The converter Ruby gem source code distribution also has samples of individual RFC XML features [14], in v2 and v3, and examples of self-standing Asciidoctor RFC XML documents [15], along with their RFC XML renderings. (This includes round-tripped RFC XML documents.) In addition, you can clone the sample "rfc-in-asciidoc-template" repository as a template, and populate it for your AsciiDoc RFCs and Internet-Drafts: $ git clone https://github.com/riboseinc/rfc-in-asciidoc-template Converting your AsciiDoc to RFC XML is a simple as installing asciidoctor (see ) and the "asciidoctor-rfc" gem in Ruby, then running the asciidoctor executable on the document, specifying the asciidoctor-rfc gem as a library: Tse, et al. Expires May 24, 2018 [Page 27] Internet-Draft AsciiRFC Specifications November 2017 $ git clone https://github.com/riboseinc/asciidoctor-rfc.git $ cd asciidoctor-rfc $ bundle install $ gem build asciidoctor-rfc.gemspec $ gem install asciidoctor-rfc $ asciidoctor -b rfc3 -r 'asciidoctor-rfc' a.adoc # RFC XML v3 output $ asciidoctor -b rfc2 -r 'asciidoctor-rfc' a.adoc # RFC XML v2 output As you author Asciidoctor content, you should iterate through running the Asciidoctor conversion frequently, to ensure that you are still generating valid XML through your markup. The converter makes an effort to ensure that its XML output is valid, and it issues warnings about likely issues; it also validates its own XML output against the Asciidoctor schema, and reports errors in the XML output in the following format: V3 RELAXNG Validation: 12:0: ERROR: Invalid attribute sortRefs for element rfc Note that validation against the RELAXNG RFC XML schema includes confirming the referential integrity of all cross-references in the document. It may be necessary to intervene in the XML output generated by the converter, either because the block model of Asciidoctor does not conform with the intended RFC XML (e.g. lists embedded in paragraphs), or because RFC XML features are required that are not supported within Asciidoctor. 20. Security Considerations o Ensure your AsciiRFC generator comes from a geniune and trustworthy source. This protects your own machine and also prevents injection of malicious content in your document. o An AsciiRFC generator may cause errors in textual rendering or link generation that may lead to security issues. o Creating cross-references (and also bibliographic references) to external documents may pose risks since the external document's location may become controlled by a malicious party. 21. IANA Considerations This document does not require any action by IANA. Tse, et al. Expires May 24, 2018 [Page 28] Internet-Draft AsciiRFC Specifications November 2017 22. Examples 22.1. Example 1 TODO. 23. References 23.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7749] Reschke, J., "The "xml2rfc" Version 2 Vocabulary", RFC 7749, DOI 10.17487/RFC7749, February 2016, . [RFC7991] Hoffman, P., "The "xml2rfc" Version 3 Vocabulary", RFC 7991, DOI 10.17487/RFC7991, December 2016, . 23.2. Informative References [RFC5385] Touch, J., "Version 2.0 Microsoft Word Template for Creating Internet Drafts and RFCs", RFC 5385, DOI 10.17487/RFC5385, February 2010, . [RFC7328] Gieben, R., "Writing I-Ds and RFCs Using Pandoc and a Bit of XML", RFC 7328, DOI 10.17487/RFC7328, August 2014, . [RFC7763] Leonard, S., "The text/markdown Media Type", RFC 7763, DOI 10.17487/RFC7763, March 2016, . [RFC7764] Leonard, S., "Guidance on Markdown: Design Philosophies, Stability Strategies, and Select Registrations", RFC 7764, DOI 10.17487/RFC7764, March 2016, . [RFC7990] Flanagan, H., "RFC Format Framework", RFC 7990, DOI 10.17487/RFC7990, December 2016, . Tse, et al. Expires May 24, 2018 [Page 29] Internet-Draft AsciiRFC Specifications November 2017 23.3. URIs [1] https://github.com/miekg/mmark [2] https://github.com/cabo/kramdown-rfc2629 [3] https://daringfireball.net/projects/markdown/ [4] http://asciidoctor.org [5] http://asciidoctor.org/docs/user-manual/#compared-to-markdown [6] http://asciidoctor.org/docs/user-manual/#compared-to-markdown [7] http://docs.mathjax.org/en/latest/asciimath.html [8] http://docs.mathjax.org/en/latest/tex.html [9] https://www.mathjax.org [10] http://asciidoctor.org/docs/user-manual/#complex-list-content [11] http://asciidoctor.org/docs/user-manual/#include-directive [12] https://github.com/riboseinc/asciidoctor-bibliography [13] http://asciidoctor.org/docs/user-manual [14] https://github.com/riboseinc/asciidoctor- rfc/tree/master/spec/asciidoctor/rfc [15] https://github.com/riboseinc/asciidoctor-rfc/tree/master/spec/ examples Appendix A. Acknowledgements The authors would like to thank the following persons for their valuable advice and input. o TODO. Authors' Addresses Tse, et al. Expires May 24, 2018 [Page 30] Internet-Draft AsciiRFC Specifications November 2017 Ronald Henry Tse Ribose Suite 1111, 1 Pedder Street Central, Hong Kong Hong Kong Email: ronald.tse@ribose.com URI: https://www.ribose.com Nick Nicholas Ribose Australia Email: nick.nicholas@ribose.com URI: https://www.ribose.com Paolo Brasolin Ribose Suite 1111, 1 Pedder Street Central, Hong Kong Hong Kong Email: jeffrey.lau@ribose.com URI: https://www.ribose.com Paolo Brasolin Ribose Italy Email: paolo.brasolin@ribose.com URI: https://www.ribose.com Tse, et al. Expires May 24, 2018 [Page 31]