Internet Engineering Task Force (IETF)                        S. Leonard
Request for Comments: 7763                                 Penango, Inc.
Category: Informational                                       March 2016
ISSN: 2070-1721


                      The text/markdown Media Type

Abstract

   This document registers the text/markdown media type for use with
   Markdown, a family of plain-text formatting syntaxes that optionally
   can be converted to formal markup languages such as HTML.

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 Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   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/rfc7763.

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.  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.







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Table of Contents

   1. Introduction  . . . . . . . . . . . . . . . . . . . . . . . . .  2
     1.1. This Is Markdown! Or: Markup and Its Discontents  . . . . .  2
     1.2. Markdown Is About Writing and Editing . . . . . . . . . . .  3
     1.3. Definitions . . . . . . . . . . . . . . . . . . . . . . . .  5
   2. Markdown Media Type Registration Application  . . . . . . . . .  5
   3. Fragment Identifiers  . . . . . . . . . . . . . . . . . . . . .  8
     3.1. Parameters  . . . . . . . . . . . . . . . . . . . . . . . .  8
   4.  Content Disposition and preview-type . . . . . . . . . . . . .  9
   5.  Example  . . . . . . . . . . . . . . . . . . . . . . . . . . .  9
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 10
     6.1. Markdown Variants . . . . . . . . . . . . . . . . . . . . . 10
   7. Security Considerations . . . . . . . . . . . . . . . . . . . . 13
   8. References  . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     8.1. Normative References  . . . . . . . . . . . . . . . . . . . 13
     8.2. Informative References  . . . . . . . . . . . . . . . . . . 14
   Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 15

1.  Introduction

1.1.  This Is Markdown! Or: Markup and Its Discontents

   In computer systems, textual data is stored and processed using a
   continuum of techniques.  On the one end is plain text: computer-
   encoded text that consists only of a sequence of code points from a
   given standard, with no other formatting or structural information
   [UNICODE].  (On the other end is binary data, which computer systems
   store and process with bit-for-bit accuracy.) Many of these standards
   include control characters that are used as in-band signaling to
   cause effects other than the addition of a symbol (or grapheme) to
   the text.

   Markup offers an alternative means to encode this signaling
   information by overloading certain graphic characters (see, e.g.,
   [ISO646]) with additional meanings.  Therefore, markup languages
   allow for annotating a document in a syntactically distinguishable
   way from the text, while keeping the annotations printable.  Markup
   languages are (reasonably) well-specified and tend to follow (mostly)
   standardized syntax rules.  Examples of formal markup languages
   include Standard Generalized Markup Language (SGML), HTML, XML, and
   LaTeX.  Standardized rules lead to interoperability between markup
   processors, but they impose skill requirements on new users that lead
   to markup languages becoming less accessible to beginners.  These
   rules also reify "validity": content that does not conform to the
   rules is treated differently (i.e., is rejected) than content that
   conforms.




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   In contrast to formal markup languages, lightweight markup languages
   use simple syntaxes; they are designed to be easy for humans to enter
   and understand with basic text editors.  Markdown, the subject of
   this document, began as an /informal/ plain-text formatting syntax
   [MDSYNTAX] and Perl script HTML/XHTML processor [MARKDOWN] targeted
   at non-technical users using unspecialized tools, such as plain-text
   email clients.  [MDSYNTAX] explicitly rejects the notion of validity:
   there is no such thing as "invalid" Markdown.  If the Markdown
   content does not result in the "right" output (defined as output that
   the author wants, not output that adheres to some dictated system of
   rules), the expectation is that the author should continue
   experimenting by changing the content or the processor to achieve the
   desired output.

   Since its development in 2004 [MARKDOWN], a number of web- and
   Internet-facing applications have incorporated Markdown into their
   text-entry systems, frequently with custom extensions.  Markdown has
   thus evolved into a kind of Internet meme [INETMEME] as different
   communities encounter it and adapt the syntax for their specific use
   cases.  Markdown now represents a family of related plain-text
   formatting syntaxes and implementations that, while broadly
   compatible with humans [HUMANE], are intended to produce different
   kinds of outputs that push the boundaries of mutual intelligibility
   between software systems.

   To support identifying and conveying Markdown, this document defines
   a media type and parameters that indicate the Markdown author's
   intent on how to interpret the content.  This registration draws
   particular inspiration from text/troff [RFC4263], which is a plain-
   text formatting syntax for typesetting based on tools from the 1960s
   ("RUNOFF") and 1970s ("nroff", et al.).  In that sense, Markdown is a
   kind of troff for modern computing.  A companion document [RFC7764]
   provides additional Markdown background, philosophy, local storage
   strategies, and variant registrations (including examples).

1.2.  Markdown Is About Writing and Editing

     "HTML is a *publishing* format; Markdown is a *writing* format.
      Thus, Markdown's formatting syntax only addresses issues that can
      be conveyed in plain text." [MDSYNTAX]

   The paradigmatic use case for text/markdown is the Markdown editor:
   an application that presents Markdown content (which looks like an
   email or other piece of plain-text writing) alongside a published
   format, so that an author can see results instantaneously and can
   tweak his or her input in real time.  A significant number of
   Markdown editors have adopted "split-screen view" (or "live preview")
   technology that looks like Figure 1.



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+----------------------------------------------------------------------+
| File  Edit  (Cloud Stuff)  (Fork Me on GitHub)  Help                 |
+----------------------------------------------------------------------+
| [ such-and-such identifier ]                 [ useful statistics]    |
+----------------------------------++----------------------------------+
| (plain text, with                || (text/html, likely               |
|  syntax highlighting)            ||  rendered to screen)             |
|                                  ||                                  |
|# Introduction                    ||<h1>Introduction</h1>             |
|                                  ||                                  |
|## Markdown Is About Writing and  /|<h2>Markdown Is About Writing and |
/ Editing                          ||Editing</h2>                      |
|                                  ||                                  |
|> HTML is a *publishing* format;  ||<blockquote><p>HTML is a          |
|> Markdown is a *writing* format. || <em>publishing</em> format;      |
|> Thus, Markdown's formatting     || Markdown is a <em>writing</em>   |
|> syntax only addresses issues    || format. Thus, Markdown's         |
|> that can be conveyed in plain   <> formatting syntax only addresses |
|> text. [MDSYNTAX][]              || issues that can be conveyed in   |
|                                  || plain text. <a href="http://darin/
|The paradigmatic use case for     |/gfireball.net/projects/markdown/sy/
|`text/markdown` is the Markdown   |/ntax#html" title="Markdown: Syntax/
|editor: an application that       |/: HTML">MDSYNTAX</a>              |
|presents Markdown content         ||</p></blockquote>                 |
|...                               ||                                  |
|                                  ||<p>The paradigmatic use case for  |
|[MDSYNTAX]: http://daringfireball./| <code>text/markdown</code> is the|
/net/projects/markdown/syntax#html || Markdown editor: an application  |
|"Markdown: Syntax: HTML"          || that presents Markdown content   |
|                                  || ...</p>                          |
+----------------------------------++----------------------------------+

 LEGEND: "/" embedded in a vertical line represents a line-continuation
  marker, since a line break is not supposed to occur in that content.

          Figure 1: Markdown Split-Screen / Live Preview Editor

   To get the best results, implementations ought to produce and consume
   mutually intelligible and identifiable bits of Markdown.  That way,
   users on diverse platforms can collaborate with their tools of
   choice.  Those tools can be desktop-based (MarkdownPad, MultiMarkdown
   Composer); browser-based (Dillinger, Markable); integrated widgets
   (Discourse, GitHub); general-purpose editors (emacs, vi); or plain
   old "Notepad".  Additionally, implementations ought to have common
   ways to identify particular areas of Markdown content when the
   Markdown becomes appreciably large (e.g., book chapters and Internet-
   Drafts -- not just blog posts).  So that users have the option to use
   Markdown in MIME-capable systems to convey their works in progress,



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   not just their finished products (for which full-blown markups
   ranging from text/html to application/pdf are appropriate),
   implementations ought to label such Markdown content with a common
   media type: text/markdown.  This registration facilitates
   interoperability between these Markdown editors by conveying the
   syntax of the particular Markdown variant and the desired output
   format.

1.3.  Definitions

   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].

   Since Markdown signifies a family of related formats with varying
   degrees of formal documentation and implementation, this
   specification uses the term "variant" to identify such formats.

2.  Markdown Media Type Registration Application

   This section provides the media type registration application for the
   text/markdown media type (see Section 5.6 of [RFC6838]).

   Type name: text

   Subtype name: markdown

   Required parameters:

      charset: Per Section 4.2.1 of [RFC6838], charset is REQUIRED.
         There is no default value because neither [MDSYNTAX] nor many
         popular implementations at the time of this registration do
         either.  [MDSYNTAX] clearly describes Markdown as a "writing
         format"; its syntax rules operate on characters (specifically,
         on punctuation) rather than code points.  Many Markdown
         processors will get along just fine by operating on characters
         in the US-ASCII repertoire (specifically punctuation),
         blissfully oblivious to other characters or codes.

   Optional parameters:

      variant: An optional identifier of the specific Markdown variant
         that the author intended.  The value serves as a "hint" to the
         recipient, meaning that the recipient MAY interpret the
         Markdown as that variant, but is under no obligation to do so.
         When omitted, there is no hint; the interpretation is entirely
         up to the receiver and context.  This identifier is plain US-
         ASCII and case-insensitive.  To promote interoperability,



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         identifiers can be registered in the registry defined in
         Section 6.  If a receiver does not recognize the variant
         identifier, the receiver MAY present the identifier to a user
         to inform him or her of it.

         Other parameters MAY be included with the media type.  The
         variant SHOULD define the semantics of such other parameters.
         Additionally, the variant MAY be registered under another media
         type; this text/markdown registration does not preclude other
         registrations.

   Encoding considerations:

      Markdown content is plain-text content; any octet sequence is
      valid as long as it conforms to the character codes of the charset
      parameter.  See [RFC2046].  Markup characters in [MDSYNTAX] are
      limited to printable US-ASCII; however, other variants can define
      markup characters outside this range (including control characters
      such as NUL and characters encoded in multiple octets).

   Security considerations:

      Markdown interpreted as plain text is relatively harmless.  A text
      editor need only display the text.  The editor SHOULD take care to
      handle control characters appropriately and to limit the effect of
      the Markdown to the text-editing area itself; malicious Unicode-
      based Markdown could, for example, surreptitiously change the
      directionality of the text.  An editor for normal text would
      already take these control characters into consideration, however.

      Markdown interpreted as a precursor to other formats, such as
      HTML, carries all of the security considerations as the target
      formats.  For example, HTML can contain instructions to execute
      scripts, redirect the user to other web pages, download remote
      content, and upload personally identifiable information.  Markdown
      also can contain islands of formal markup, such as HTML.  These
      islands of formal markup may be passed as they are, transformed,
      or ignored (perhaps because the islands are conditional or
      incompatible) when the Markdown is processed.  Since Markdown may
      have different interpretations depending on the tool and the
      environment, a better approach is to analyze (and sanitize or
      block) the output markup, rather than attempting to analyze the
      Markdown.








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   Interoperability considerations:

      Markdown variations (some might say "innovations") are designed to
      be broadly compatible with humans ("humane"), but not necessarily
      with each other.  Therefore, syntax in one Markdown derivative may
      be ignored or treated differently in another derivative.  The
      overall effect is a general degradation of the output that
      increases with the quantity of variant-specific Markdown used in
      the text.  When it is desirable to reflect the author's intent in
      the output, stick with the variant identified in the variant
      parameter, i.e., receivers SHOULD only accept Markdown variants
      that they explicitly know about, and senders SHOULD avoid use of
      variants that intended recipients are not known to understand.

   Published specification: This specification; [MDSYNTAX].

   Applications that use this media type:

      Markdown conversion tools, Markdown WYSIWYG (What You See is What
      You Get) editors, and plain-text editors and viewers; markup
      processor targets indirectly use Markdown (e.g., web browsers for
      Markdown converted to HTML).

   Fragment identifier considerations:

      See Section 3.

   Additional information:

      Magic number(s): None
      File extension(s): .md, .markdown
      Macintosh file type code(s):
         TEXT.  A uniform type identifier (UTI) of
         "net.daringfireball.markdown", which conforms to
         "public.plain-text", is RECOMMENDED [MDUTI].  See [RFC7764] for
         other considerations.

   Person & email address to contact for further information:

      Sean Leonard <[email protected]>

   Restrictions on usage: None.

   Author/Change controller: Sean Leonard <[email protected]>

   Intended usage: COMMON

   Provisional registration? No



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   Implementations SHOULD record the value of the variant parameter (and
   other parameters if defined by the variant) along with the Markdown
   content when the content leaves the domain of formats that are
   Internet media type capable.  Strategies for doing so are discussed
   in [RFC7764].

   The Content-Disposition header (particularly the preview-type
   parameter) can be used with Markdown content.  See Section 4.

3.  Fragment Identifiers

   [MARKDOWN] does not define any fragment identifiers, but some
   variants do, and many types of Markdown processor output (e.g., HTML
   or PDF) will have well-defined fragment identifiers.  Which fragment
   identifiers are available for a given document are variant-defined.

   When encoded in a URI, characters that are outside of the fragment
   production of [RFC3986] are percent-encoded.  The default encoding
   (character set) of percent-encoded octets in URIs is the same as the
   Markdown content, which is identified by the charset parameter or by
   other contextual means.  Fragment identifiers SHOULD be considered
   case-sensitive, which maintains consistency with HTML.  Variants MAY
   override the guidance in this paragraph.

   At least the first equals sign "=" SHOULD be percent-encoded to
   prevent ambiguity as described in the following section.

3.1.  Parameters

   Similar to application/pdf [RFC3778] and text/plain [RFC5147], this
   registration permits a parameter syntax for fragment identifiers.
   The syntax is a parameter name, the equals sign "=" (which MUST NOT
   be percent-encoded), and a parameter value.  To the extent that
   multiple parameters can appear in a fragment production, the
   parameters SHALL be separated by the ampersand "&" (which MUST NOT be
   percent-encoded).

   The only parameter defined in this registration is "line", which has
   the same meaning as in [RFC5147], i.e., counting is zero-based.  For
   example: "#line=10" identifies the eleventh line of Markdown input.
   Implementers should take heed that different environments and
   character sets may have a wide range of code sequences to divide
   lines.

   Markdown variants are free to define additional parameters.






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4.  Content Disposition and preview-type

   The Content-Disposition header [RFC2183] conveys presentational
   information about a MIME entity, using a type and set of parameters.
   The parameter preview-type is defined here for Markdown content.

   When present, preview-type indicates the Internet media type (and
   parameters) of the preview output desired from the processor by the
   author.  With reference to the "paradigmatic use case" (i.e.,
   collaborative Markdown editing) in Section 1.3, the preview-type
   parameter primarily affects the "right-hand" side of a Markdown
   editor.  There is no default value: when absent, a Markdown user
   agent can render or display whatever it wants.

   The value of this parameter is an Internet media type with optional
   parameters.  The syntax (including case-sensitivity considerations)
   is the same as specified in [RFC2045] for the Content-Type header
   (with updates over time, e.g., [RFC2231] and [RFC6532]).

   Implementations SHOULD anticipate and support HTML (text/html) and
   XHTML (application/xhtml+xml) output, to the extent that a syntax
   targets those markup languages.  These types ought to be suitable for
   the majority of current purposes.  However, Markdown is increasingly
   becoming integral to workflows where HTML is not the target output;
   examples range from TeX, to PDF, to Outline Processor Markup Language
   (OPML), and even to entire e-books (e.g., [PANDOC]).

   The reflexive media type text/markdown in this parameter value means
   that the author does not want to invoke Markdown processing at all:
   the receiver SHOULD present the Markdown source as is.

   The preview-type parameter can be used for other types of content,
   but the precise semantics are not defined here.

5.  Example

   The following is an example of Markdown as an email attachment:

    MIME-Version: 1.0
    Content-Type: text/markdown; charset=UTF-8; variant=Original
    Content-Disposition: attachment; filename=readme.md;
     preview-type="application/xhtml+xml"

    Sample HTML 4 Markdown
    =============

    This is some sample Markdown. [Hooray!][foo]
    (Remember that link identifiers are not case-sensitive.)



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    Bulleted Lists
    -------

    Here are some bulleted lists...

    * One Potato
    * Two Potato
    * Three Potato

    - One Tomato
    - Two Tomato
    - Three Tomato

    More Information
    -----------

    [.markdown, .md](http://daringfireball.net/projects/markdown/)
    has more information.

    [fOo]: http://example.com/loc 'Will Not Work with Markdown.pl-1.0.1'

6.  IANA Considerations

   IANA has registered the media type text/markdown using the
   application provided in Section 2 of this document.

   IANA has registered preview-type in the "Content Disposition
   Parameters" subregistry of the "Content Disposition Values and
   Parameters" registry, with the following description: "Internet media
   type (and parameters) of the preview output desired from a processor
   by the author of the MIME content".

6.1.  Markdown Variants

   IANA has established a registry called "Markdown Variants".  While
   the registry has been created in the context of the text/markdown
   media type, the registry is intended for broad community use, so
   protocols and systems that do not rely on Internet media types can
   still tag Markdown content with a common variant identifier.  Each
   entry in this registry shall consist of basic information about the
   variant:










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   Identifier:             unique identifier for the variant
   Name:                   the commonly known name of the variant
   Description:            a prose description of the variant, including
                           how it differs from other variants such as
                           Original
   Additional Parameters*: additional Content-Type parameters
   Fragment Identifiers*:  additional fragment identifier syntaxes and
                           semantics
   References:             URIs or other references to documentation
   Contact Information:    whom to contact (email, URI, phone, address,
                           etc.)
   Expiration Date^:       when this provisional registration expires

   * (optional)
   ^ (if provisional)

   While the variant parameter is "plain US-ASCII" (see registration
   template), the Identifier field (and by implication, all registered
   identifiers) SHALL conform to the ABNF [RFC5234]:

      ALPHA [*VCHAR (ALPHA / DIGIT)]

   For style and compatibility reasons, the Identifier field SHOULD
   conform to the ABNF:

      ALPHA *( ["-" / "." / "_" / "~"] 1*(ALPHA / DIGIT) )

   That is, the identifier MUST start with a letter and MAY contain
   punctuation in the middle, but not at the end: the last character
   MUST be alphanumeric.  The second production uses the same characters
   as the "unreserved" rule of [RFC3986] and is designed to be
   compatible with characters in other identification systems, e.g.,
   filenames.  Since the identifier MAY be displayed to a user --
   particularly in cases where the receiver does not recognize the
   identifier -- the identifier SHOULD be rationally related to the
   vernacular name of the variant.

   The Name, Description, Additional Parameters, Fragment Identifiers,
   References, and Contact Information fields SHALL be in a Unicode
   character set (e.g., UTF-8).

   The registry includes the registration in Section 6.1.4 (Original
   Markdown).  [RFC7764] includes additional registrations.








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6.1.1.  Reserved Identifiers

   The registry has the following identifiers RESERVED, as they have
   engendered some controversy in the Markdown community.  No one is
   allowed to register them (or any case variations of them).  These
   identifiers are not and cannot be registered:
      Standard
      Common
      Markdown

   The registry includes the following text in the note field:
   The variant names Standard, Common, and Markdown are reserved and
   cannot be registered.

6.1.2.  Standard of Review

   Registrations are made on a First Come, First Served [RFC5226] basis
   by anyone with a need to interoperate.  While documentation is
   required, any level of documentation is sufficient; thus, neither
   Specification Required nor Expert Review are warranted.  The checks
   prescribed by this section can be performed automatically.

   All references (including contact information) MUST be verified as
   functional at the time of the registration.

   As a special "escape valve", registrations can be updated with IETF
   Review [RFC5226].  All fields may be updated except the variant
   identifier, which is permanent: not even case may be changed.

6.1.3.  Provisional Registration

   Any registrant may make a provisional registration to reserve a
   variant identifier.  Only the variant identifier and contact
   information fields are required; the rest are optional.  Provisional
   registrations expire after three months, after which time the variant
   identifier may be reused.  To make a registration permanent, a
   registrant simply needs to complete a permanent registration with the
   same identifier as the provisional registration.

6.1.4.  Original Markdown

   The registry includes this initial variant.  A conforming
   implementation that processes the variant parameter MUST recognize
   this variant (although the processing behavior is not defined here).

   Identifier: Original

   Name: Markdown



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   Description:
      Gruber's original Markdown syntax.

   References:
      [MARKDOWN]
      [MDSYNTAX]

   Contact Information:
      (individual) John Gruber <http://daringfireball.net/>
                               <[email protected]>

7.  Security Considerations

   See the Security considerations entry in Section 2.

8.  References

8.1.  Normative References

   [MARKDOWN] Gruber, J., "Daring Fireball: Markdown", December 2004,
              <http://daringfireball.net/projects/markdown/>.

   [MDSYNTAX] Gruber, J., "Daring Fireball: Markdown Syntax
              Documentation", December 2004,
              <http://daringfireball.net/projects/markdown/syntax>.

   [MDUTI]    Gruber, J., "Daring Fireball: Uniform Type Identifier for
              Markdown", August 2011,
              <http://daringfireball.net/linked/2011/08/05/
              markdown-uti>.

   [RFC2045]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part One: Format of Internet Message
              Bodies", RFC 2045, DOI 10.17487/RFC2045, November 1996,
              <http://www.rfc-editor.org/info/rfc2045>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC2183]  Troost, R., Dorner, S., and K. Moore, Ed., "Communicating
              Presentation Information in Internet Messages: The
              Content-Disposition Header Field", RFC 2183,
              DOI 10.17487/RFC2183, August 1997,
              <http://www.rfc-editor.org/info/rfc2183>.





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   [RFC2231]  Freed, N. and K. Moore, "MIME Parameter Value and Encoded
              Word Extensions: Character Sets, Languages, and
              Continuations", RFC 2231, DOI 10.17487/RFC2231, November
              1997, <http://www.rfc-editor.org/info/rfc2231>.

   [RFC3778]  Taft, E., Pravetz, J., Zilles, S., and L. Masinter, "The
              application/pdf Media Type", RFC 3778,
              DOI 10.17487/RFC3778, May 2004,
              <http://www.rfc-editor.org/info/rfc3778>.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <http://www.rfc-editor.org/info/rfc3986>.

   [RFC5147]  Wilde, E. and M. Duerst, "URI Fragment Identifiers for the
              text/plain Media Type", RFC 5147, DOI 10.17487/RFC5147,
              April 2008, <http://www.rfc-editor.org/info/rfc5147>.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              DOI 10.17487/RFC5226, May 2008,
              <http://www.rfc-editor.org/info/rfc5226>.

   [RFC5234]  Crocker, D., Ed., and P. Overell, "Augmented BNF for
              Syntax Specifications: ABNF", STD 68, RFC 5234,
              DOI 10.17487/RFC5234, January 2008,
              <http://www.rfc-editor.org/info/rfc5234>.

   [RFC6532]  Yang, A., Steele, S., and N. Freed, "Internationalized
              Email Headers", RFC 6532, DOI 10.17487/RFC6532, February
              2012, <http://www.rfc-editor.org/info/rfc6532>.

   [RFC6838]  Freed, N., Klensin, J., and T. Hansen, "Media Type
              Specifications and Registration Procedures", BCP 13,
              RFC 6838, DOI 10.17487/RFC6838, January 2013,
              <http://www.rfc-editor.org/info/rfc6838>.

8.2.  Informative References

   [HUMANE]   Atwood, J., "Is HTML a Humane Markup Language?", May 2008,
              <http://blog.codinghorror.com/
              is-html-a-humane-markup-language/>.








Leonard                       Informational                    [Page 14]


RFC 7763              The text/markdown Media Type            March 2016


   [INETMEME] Solon, O., "Richard Dawkins on the internet's hijacking of
              the word 'meme'", June 2013,
              <http://www.wired.co.uk/news/archive/2013-06/20/
              richard-dawkins-memes>,
              <http://www.webcitation.org/6HzDGE9Go>.

   [ISO646]   International Organization for Standardization,
              "Information technology - ISO 7-bit coded character set
              for information interchange", ISO Standard 646, 1991.

   [PANDOC]   MacFarlane, J., "Pandoc", 2014,
              <http://johnmacfarlane.net/pandoc/>.

   [RFC2046]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part Two: Media Types", RFC 2046,
              DOI 10.17487/RFC2046, November 1996,
              <http://www.rfc-editor.org/info/rfc2046>.

   [RFC4263]  Lilly, B., "Media Subtype Registration for Media Type
              text/troff", RFC 4263, DOI 10.17487/RFC4263, January 2006,
              <http://www.rfc-editor.org/info/rfc4263>.

   [RFC7764]  Leonard, S., "Guidance on Markdown: Design Philosophies,
              Stability Strategies, and Select Registrations", RFC 7764,
              DOI 10.17487/RFC7764, March 2016,
              <http://www.rfc-editor.org/info/rfc7764>.

   [UNICODE]  The Unicode Consortium, "The Unicode Standard, Version
              8.0", (Mountain View, CA: The Unicode Consortium, 2015.
              ISBN 978-1-936213-10-8),
              <http://www.unicode.org/versions/Unicode8.0.0/>.

Author's Address

   Sean Leonard
   Penango, Inc.
   5900 Wilshire Boulevard
   21st Floor
   Los Angeles, CA  90036
   United States

   Email: [email protected]
   URI:   http://www.penango.com/








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