Re: [dispatch] WGLC: draft-ietf-dispatch-javascript-mjs-02.txt

"L. David Baron" <> Wed, 11 July 2018 01:05 UTC

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Date: Wed, 11 Jul 2018 11:05:05 +1000
From: "L. David Baron" <>
To: Mary Barnes <>
Cc: DISPATCH <>,, Barry Leiba <>
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Subject: Re: [dispatch] WGLC: draft-ietf-dispatch-javascript-mjs-02.txt
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Hi -

I have a few comments on the document:

There are two things that might be read to imply that processors
(e.g., browsers) should change their behavior as a result of file
extensions.  In particular, in section 4 (Registration):

                                                           In addition,
   a new file extension of .mjs is to be added to the list of file
   extensions with the restriction that it must correspond to the Module
   grammar of [ECMA-262].

and then repeatedly in the subsections of that section:

   Restrictions on usage:  The file extension .mjs must be parsed using
      the Module grammar of [ECMA-262] 

This seems like a reasonable thing to suggest as the intended use of
the .mjs extension, but I think it could be read to imply that
implementations should change their behavior as a result of file
extensions, which would be a rather unusual requirement on the Web.

If that requirement were the intent, it would seem to contradict the
processing rules for script elements in the HTML specification at:
which specify that the type attribute on the script element
determines whether a script is interpreted as a classic script or as
a module script.

Additionally, I wonder whether it would be useful to have a section
that documents the changes from RFC4329.  The introduction to
section 4 (Registration) seems to document some of them, but I
noticed that it doesn't mention that application/ecmascript and
application/javascript have been changed to Obsolete, and a number
of types not previously listed in RFC4329 (but listed in have been
added as Obsolete.  (I didn't check for other differences.)

I'm happy to see the obsolete/common distinction in this draft
reflecting current practice.


On Tuesday 2018-07-10 13:15 -0500, Mary Barnes wrote:
> Hi all,
> We would like to start a 2 week WGLC for this document.    If you think the
> document is ready, please respond to this email.  If you have comments that
> you would like considered and/or any editorial suggestions, please post
> those as well.
> The WGLC ends on July 25, 2018.
> Regards,
> Mary
> DISPATCH WG tri-chair
> ---------- Forwarded message ----------
> From: <>;
> Date: Tue, May 8, 2018 at 5:41 PM
> Subject: [dispatch] I-D Action: draft-ietf-dispatch-javascript-mjs-02.txt
> To:
> Cc:
> A New Internet-Draft is available from the on-line Internet-Drafts
> directories.
> This draft is a work item of the Dispatch WG of the IETF.
>         Title           : ECMAScript Media Types Updates
>         Authors         : Bradley Farias
>                           Matthew A. Miller
>         Filename        : draft-ietf-dispatch-javascript-mjs-02.txt
>         Pages           : 21
>         Date            : 2018-05-08
> Abstract:
>    This document proposes updates to the ECMAScript media types,
>    superseding the existing registrations for "application/javascript"
>    and "text/javascript" by adding an additional extension and removing
>    usage warnings.  This document updates RFC4329, "Scripting Media
>    Types".
> The IETF datatracker status page for this draft is:
> There are also htmlized versions available at:
> A diff from the previous version is available at:
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at
> Internet-Drafts are also available by anonymous FTP at:
> _______________________________________________
> dispatch mailing list

đť„ž   L. David Baron                  đť„‚
𝄢   Mozilla                   𝄂
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