DISPATCH                                                       B. Farias                                                       M. Borins
Internet-Draft                                                 M. Bynens
Updates: 4329 (if approved)                                    M. Miller                                       Google
Intended status: Informational                                   Mozilla                                 M. Miller
Expires: November 9, 2018                                   May 08, 2018 August 26, 2019                                         Mozilla
                                                               B. Farias
                                                       February 22, 2019

                     ECMAScript Media Types Updates
                 draft-ietf-dispatch-javascript-mjs-02
                 draft-ietf-dispatch-javascript-mjs-03

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".

Note to Readers

   The issues list for this draft can be found at
   https://github.com/bmeck/I-D/labels/javascript-mjs [1].

   The most recent (often, unpublished) draft is at
   https://github.com/bmeck/I-D/tree/master/javascript-mjs [2].

   Recent changes are listed at https://github.com/bmeck/I-
   D/commits/master/javascript-mjs [3].

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 November 9, 2018. August 26, 2019.

Copyright Notice

   Copyright (c) 2018 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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Background  . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Notational Conventions  . . . .  IANA Considerations . . . . . . . . . . . . . . .   3
   4.  Registration  . . . . . . . . . .   3
     3.1.  Common Javascript Media Types . . . . . . . . . . . . . .   3
     4.1.  application/ecmascript  . .
       3.1.1.  text/javascript . . . . . . . . . . . . . . .   3
     4.2.  application/javascript . . . .   3
     3.2.  Historic Javascript Media Types . . . . . . . . . . . . .   4
     4.3.  application/x-ecmascript  .
       3.2.1.  application/ecmascript  . . . . . . . . . . . . . . .   5
     4.4.  application/x-javascript  .
       3.2.2.  application/javascript  . . . . . . . . . . . . . . .   6
     4.5.  text/ecmascript
       3.2.3.  application/x-ecmascript  . . . . . . . . . . . . . .   7
       3.2.4.  application/x-javascript  . . . . . . .   7
     4.6.  text/javascript . . . . . . .   8
       3.2.5.  text/ecmascript . . . . . . . . . . . . . .   8
     4.7.  text/javascript1.0 . . . . .   9
       3.2.6.  text/javascript1.0  . . . . . . . . . . . . . .   9
     4.8.  text/javascript1.1  . . . .  10
       3.2.7.  text/javascript1.1  . . . . . . . . . . . . . . .  10
     4.9.  text/javascript1.2 . .  11
       3.2.8.  text/javascript1.2  . . . . . . . . . . . . . . . . .  11
     4.10.  12
       3.2.9.  text/javascript1.3  . . . . . . . . . . . . . . . . . . .  12
     4.11.  13
       3.2.10. text/javascript1.4  . . . . . . . . . . . . . . . . . . .  13
     4.12.  14
       3.2.11. text/javascript1.5  . . . . . . . . . . . . . . . . . . .  14
     4.13.  15
       3.2.12. text/jscript  . . . . . . . . . . . . . . . . . . . . . .  15
     4.14.  16
       3.2.13. text/livescript . . . . . . . . . . . . . . . . . . . . .  16
     4.15.  17
       3.2.14. text/x-ecmascript . . . . . . . . . . . . . . . . . . . .  17
     4.16.  18
       3.2.15. text/x-javascript . . . . . . . . . . . . . . . . . . . .  18
   5.  19
   4.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  19
     5.1.  20
     4.1.  Normative References  . . . . . . . . . . . . . . . . . .  19
     5.2.  20
     4.2.  Informative References  . . . . . . . . . . . . . . . . .  20
     5.3.
     4.3.  URIs  . . . . . . . . . . . . . . . . . . . . . . . . . .  20  21
   Appendix A.  Acknowledgements . . . . . . . . . . . . . . . . . .  20  21
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  20  21

1.  Introduction

   This document updates the existing media types for the ECMAScript
   programming language.  It supersedes the media types registrations in
   [RFC4329] for "application/javascript" and "text/javascript".

2.  Background

   In order to formalize support for modular programs [ECMA-262] now
   defines two top-level goal symbols for the ECMAScript grammar.  This
   means that (in the absence of additional information) there are two
   possible interpretations for any given ECMAScript Source Text.  The
   TC39 standards body for ECMAScript has determined that media types
   are outside of their scope of work [TC39-MIME-ISSUE].

   It is not possible to fully determine if a Source Text of ECMAScript
   is meant to be parsed in the Module or Script grammar goals based
   upon content alone.  Therefore, scripting environments must use out
   of band information in order to determine what goal a Source Text
   should be treated as.  To this end some scripting environments have
   chosen to adopt a new file extension of .mjs for determining the goal
   of a given Source Text.

3.  Notational Conventions  IANA Considerations

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document media type registrations herein are to be interpreted as described divided into two major
   categories: the sole media type "text/javascript" which is now in [RFC2119].

4.  Registration
   common usage, and all of the media types that are obsolete.

   For both categories, The ECMAScript media types are to be updated to
   point to a non-vendor specific standard undated specification of
   ECMAScript.  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].  Finally, the [HTML]
   specification is using
   text/javascript "text/javascript" as the default media type of
   ECMAScript when preparing script tags; therefore, text/javascript "text/javascript"
   has been moved intended usage from OBSOLETE to COMMON.

4.1.  application/ecmascript

3.1.  Common Javascript Media Types

3.1.1.  text/javascript

   Type name:  application  text

   Subtype name:  ecmascript  javascript

   Required parameters:  none
   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .es,  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE  COMMON

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

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.2.  application/javascript

3.2.  Historic Javascript Media Types

   The following media types are added or updated for historical
   purposes.  All herein have an intended usage of OBSOLETE, and are not
   expected to be in use with modern implementations.

3.2.1.  application/ecmascript

   Type name:  application

   Subtype name:  javascript  ecmascript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js,  .es, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>.

4.3.  application/x-ecmascript <iesg@ietf.org>

3.2.2.  application/javascript

   Type name:  application

   Subtype name:  x-ecmascript  javascript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .es,  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.4.  application/x-javascript <iesg@ietf.org>.

3.2.3.  application/x-ecmascript

   Type name:  application

   Subtype name:  x-javascript  x-ecmascript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js,  .es, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.5.  text/ecmascript

3.2.4.  application/x-javascript

   Type name:  text  application

   Subtype name:  ecmascript  x-javascript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .es,  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE
   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.6.  text/javascript

3.2.5.  text/ecmascript

   Type name:  text

   Subtype name:  javascript  ecmascript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js,  .es, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  COMMON  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.7.

3.2.6.  text/javascript1.0

   Type name:  text

   Subtype name:  javascript1.0

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.8.

3.2.7.  text/javascript1.1

   Type name:  text

   Subtype name:  javascript1.1

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js, .mjs
      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.9.

3.2.8.  text/javascript1.2

   Type name:  text

   Subtype name:  javascript1.2

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a
      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.10.

3.2.9.  text/javascript1.3

   Type name:  text

   Subtype name:  javascript1.3

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.11.

3.2.10.  text/javascript1.4

   Type name:  text

   Subtype name:  javascript1.4

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.12.

3.2.11.  text/javascript1.5

   Type name:  text

   Subtype name:  javascript1.5

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]
   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

   Restrictions on usage:  This media type is obsolete; current
      implementations should use text/javascript as the only javascript/
      ECMAscript media type.  The file extension .mjs must be parsed
      using the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.13.

3.2.12.  text/jscript

   Type name:  text

   Subtype name:  jscript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

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

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.14.

3.2.13.  text/livescript

   Type name:  text

   Subtype name:  livescript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

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

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.15.

3.2.14.  text/x-ecmascript

   Type name:  text

   Subtype name:  x-ecmascript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .es, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

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

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.16.

3.2.15.  text/x-javascript

   Type name:  text

   Subtype name:  x-javascript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

      goal, declares the goal symbol in the Syntactic Grammars of
      [ECMA-262] to be used while parsing.  This parameter is case
      insensitive.

   Encoding considerations:  Encoding is host dependent with differences
      in byte order marks, the charset parameter, and text
      preprocessing.

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used when missing the goal parameter.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  OBSOLETE

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

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

5.

4.  References

5.1.

4.1.  Normative References

   [ECMA-262]
              Ecma International, "Standard ECMA-262: ECMAScript
              Language Specification", August 2017, <http://www.ecma-
              international.org/publications/standards/Ecma-262.htm>.

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

   [RFC3023]  Murata, M., St. Laurent, S., and D. Kohn, "XML Media
              Types", RFC 3023, DOI 10.17487/RFC3023, January 2001,
              <https://www.rfc-editor.org/info/rfc3023>.

   [RFC4329]  Hoehrmann, B., "Scripting Media Types", RFC 4329,
              DOI 10.17487/RFC4329, April 2006,
              <https://www.rfc-editor.org/info/rfc4329>.

5.2.

4.2.  Informative References

   [HTML]     WHATWG, "HTML Living Standard", August 2017,
              <https://html.spec.whatwg.org/multipage/
              scripting.html#prepare-a-script>.

   [TC39-MIME-ISSUE]
              TC39, "Add `application/javascript+module` mime to remove
              ambiguity5", August 2017, <https://web.archive.org/web/201
              70814193912/https://github.com/tc39/ecma262/issues/322>.

5.3.

4.3.  URIs

   [1] https://github.com/bmeck/I-D/labels/javascript-mjs

   [2] https://github.com/bmeck/I-D/tree/master/javascript-mjs

   [3] https://github.com/bmeck/I-D/commits/master/javascript-mjs

Appendix A.  Acknowledgements

   Thanks to Suresh Krishnan, Alexey Melnikov, Mark Nottingham, James
   Snell, Matthew A.  Miller, Adam Roach, and Allen Wirfs-Brock for guiding me through this
   process.

Authors' Addresses

   Bradley Farias

   Myles Borins
   Google

   Email: bradley.meck@gmail.com mylesborins@google.com

   Mathias Bynens
   Google

   Email: mths@google.com

   Matthew A. Miller
   Mozilla

   Email: linuxwolf+ietf@outer-planes.net

   Bradley Farias

   Email: bradley.meck@gmail.com