Markdown Discuss - Sep 2014 - Request for input: text/markdown media type

[Sent by Sean Leonard]
From: IETF Applications Area Working Group (APPSAWG)

To: markdown-discuss at six.pairlist.net 
<mailto:markdown-discuss at six.pairlist.net>
jgm at berkeley.edu <mailto:jgm at berkeley.edu>
david at meteor.com <mailto:david at meteor.com>
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jatwood at codinghorror.com <mailto:jatwood at codinghorror.com>
comments at daringfireball.net <mailto:comments at daringfireball.net>

Cc: presnick at qti.qualcomm.com <mailto:presnick at qti.qualcomm.com>
barryleiba at computer.org <mailto:barryleiba at computer.org>

Response Contact: superuser at gmail.com <mailto:superuser at gmail.com>

Technical Contact: superuser at gmail.com <mailto:superuser at gmail.com>
dev+ietf at seantek.com <mailto:dev%2Bietf at seantek.com>

Purpose: Request for input

Attachments: (none)

Body:

The Applications Area Working Group (APPSAWG) of the Internet 
Engineering  Task Force (IETF) has taken up a proposed work item to 
register a new Media Type, "text/markdown", for the purposes of 
identifying content in the Markdown format.  The current version of the 
document can be viewed here:

https://datatracker.ietf.org/doc/draft-ietf-appsawg-text-markdown/

We know Sean Leonard approached the Markdown community about starting 
this work previously (see 
http://six.pairlist.net/pipermail/markdown-discuss/2014-July/thread.html) and 
some of the questions that were discussed in that thread are also being 
asked in the working group.  In the interests of ensuring that any 
choices we make will not conflict with the positions and course of the 
Markdown community, APPSAWG would like to solicit feedback on a few 
important questions.

Part of the impetus here is that an unregistered and unspecified media 
type ?text/x-markdown? appears to be in use.  This work seeks to 
formalize this use and register the name.

Our questions for the Markdown community:

(1) We understand there is not a standard Markdown format, but rather a 
number of variants based on one original proposal. This leads us to 
wonder how a consumer would be expected to interpret this media type 
once it is registered.  Typically, a media type registration includes a 
reference to a single, stable, definition document, but we are not aware 
of such a thing for Markdown.  Can or should this work proceed without one?

Note that the IETF has no intention to undertake the work of publishing 
an RFC that contains a Markdown syntax or otherwise blessing any 
particular Markdown variant, or calling one of them ?standard".  Any 
Markdown definition document(s) would be referenced by this work and 
would be external to the IETF.

(2) One proposal to address this issue is to include a parameter that 
indicates which flavor of Markdown should be applied in order to 
translate the input when the media type is encountered.  For example:

Content-Type: text/markdown; flavor="foobar"

This would likely necessitate a registry of known variants and their 
respective defining documents so that a consumer has implementation 
guidance.  This puts some burden on the Markdown community to begin 
formally documenting and registering all of its variants that might use 
this media type.

(3) The solution in (2) above further raises the question of whether 
there should be a default variant (i.e., what to do if no ?flavor? 
clause is present), and if so, which one should be the default.  If 
there is no default, then how should a consumer interpret the absence of 
the ?flavor" tag?

(4) At the same time, it has been observed that regardless of which 
variant is in use as input, any Markdown processor will generally 
produce something useful as output.  Given this, is it necessary to know 
the ?flavor? in use at all?  Put another way: Rather than being 
concerned with variants, should "text/markdown" merely be a hint to 
consumers that the content is in some Markdown variant, and beyond that, 
caveat implementer?

(5) Does the Markdown community have any alternative suggestions in 
response to any of these questions?

We look forward to your replies, hopefully within the next several 
weeks, which can be sent to the response and technical contacts listed 
in the header of this liaison.  Markdown community participants are also 
invited to subscribe and reply to apps-discuss at ietf.org 
<mailto:apps-discuss at ietf.org> in order to address the entire working 
group directly.


M. Kucherawy
for the Applications Area Working Group, IETF