This is a purely informative rendering of an RFC that includes verified errata. This rendering may not be used as a reference.
The following 'Verified' errata have been incorporated in this document:
EID 8041
Internet Engineering Task Force (IETF) M. Miller
Request for Comments: 9239
Obsoletes: 4329 M. Borins
Category: Informational GitHub
ISSN: 2070-1721 M. Bynens
Google
B. Farias
May 2022
Updates to ECMAScript Media Types
Abstract
This document describes the registration of media types for the
ECMAScript and JavaScript programming languages and conformance
requirements for implementations of these types. This document
obsoletes RFC 4329 ("Scripting Media Types)", replacing the previous
registrations with information and requirements aligned with common
usage and implementation experiences.
IESG Note
This document records the relationship between the work of Ecma
International's Technical Committee 39 and the media types used to
identify relevant payloads.
That relationship was developed outside of the IETF and as a result
is unfortunately not aligned with the best practices of BCP 13.
Consequently, consensus exists in the IETF to document the
relationship and update the relevant IANA registrations for those
media types, but this is not an IETF endorsement of the media types
chosen for this work.
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 candidates for any level of Internet
Standard; see Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9239.
Copyright Notice
Copyright (c) 2022 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 Revised BSD License text as described in Section 4.e of the
Trust Legal Provisions and are provided without warranty as described
in the Revised BSD License.
Table of Contents
1. Introduction
1.1. Terminology
2. Compatibility
3. Modules
4. Encoding
4.1. Charset Parameter
4.2. Character Encoding Scheme Detection
4.3. Character Encoding Scheme Error Handling
5. Security Considerations
6. IANA Considerations
6.1. Common JavaScript Media Types
6.1.1. text/javascript
6.2. Historic JavaScript Media Types
6.2.1. text/ecmascript
7. References
7.1. Normative References
7.2. Informative References
Appendix A. Changes from RFC 4329
Acknowledgements
Authors' Addresses
1. Introduction
This memo describes media types for the JavaScript and ECMAScript
programming languages. Refer to the sections "Introduction" and
"Overview" in [ECMA-262] for background information on these
languages. This document updates the descriptions and registrations
for these media types to reflect existing usage on the Internet, and
it provides up-to-date security considerations.
This document replaces the media type registrations in [RFC4329] and
updates the requirements for implementations using those media types
defined in [RFC4329] based on current existing practices. As a
consequence, this document obsoletes [RFC4329].
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Compatibility
This document defines equivalent processing requirements for the
various script media types. The most widely supported media type in
use is text/javascript; all others are considered historical and
obsolete aliases of text/javascript.
The types defined in this document are applicable to scripts written
in [ECMA-262]. New editions of [ECMA-262] are subjected to strong
obligations of backward compatibility, imposed by the standardization
process of Ecma International's Technical Committee 39 (TC39). As a
result, JavaScript code based on an earlier edition is generally
compatible with a JavaScript engine adhering to a later edition. The
few exceptions to this are documented in [ECMA-262] in the section
"Additions and Changes That Introduce Incompatibilities with Prior
Editions". JavaScript developers commonly use feature detection to
ensure that modern JavaScript features are only used when available
in the current environment. Later editions of [ECMA-262] are not
directly addressed in this document, although it is expected that
implementations will behave as if applicability were extended to
them. This document does not address other extensions to [ECMA-262]
or scripts written in other languages.
This document may be updated to take other content into account.
Updates of this document may introduce new optional parameters;
implementations must consider the impact of such an update.
This document does not define how fragment identifiers in resource
identifiers [RFC3986] [RFC3987] for documents labeled with one of the
media types defined in this document are resolved. An update of this
document may define processing of fragment identifiers.
Note that this use of the "text" media type tree willfully does not
align with its original intent per [RFC2045]. The reason for this is
historical. [RFC4329] registered both the text/* and application/*
types, marking the text/* types obsolete. This was done to encourage
people toward application/*, matching the guidance in [RFC4288], the
predecessor to [RFC6838]. Since then, however, the industry widely
adopted text/* anyway. The definitions in this document reflect the
current state of implementation across the JavaScript ecosystem, in
web browsers and other environments such as Node.js alike, in order
to guarantee backward compatibility with existing applications as
much as possible. Future registrations should not view this as a
repeatable precedent.
3. Modules
In order to formalize support for modular programs, [ECMA-262]
(starting with the 6th Edition) defines two top-level goal symbols
(or roots to the abstract syntax tree) for the ECMAScript grammar:
Module and Script. The Script goal represents the original structure
where the code executes in the global scope, while the Module goal
represents the module system built into ECMAScript starting with the
6th Edition. See the section "ECMAScript Language: Scripts and
Modules" in [ECMA-262] for details.
This separation means that (in the absence of additional information)
there are two possible interpretations for any given ECMAScript
source text.
Ecma International's Technical Committee 39 (TC39), the standards
body in charge of 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 using the Module or Script grammar goals based
upon content or media type alone. Therefore, as permitted by the
media types in this document, scripting environments use out-of-band
information in order to determine what goal should be used. Some
scripting environments have chosen to adopt the file extension of
.mjs for this purpose.
4. Encoding
Refer to [RFC6365] for a discussion of terminology used in this
section. Source text (as defined in the section "Source Text" in
[ECMA-262]) can be binary source text. Binary source text is a
textual data object that represents source text encoded using a
character encoding scheme. A textual data object is a whole text
protocol message or a whole text document, or a part of it, that is
treated separately for purposes of external storage and retrieval.
An implementation's internal representation of source text is not
considered binary source text.
Implementations need to determine a character encoding scheme in
order to decode binary source text to source text. The media types
defined in this document allow an optional charset parameter to
explicitly specify the character encoding scheme used to encode the
source text.
In order to ensure interoperability and align with widespread
implementation practices, the charset parameter is optional rather
than required, despite the recommendation in BCP 13 [RFC6838] for
text/* types.
How implementations determine the character encoding scheme can be
subject to processing rules that are out of the scope of this
document. For example, transport protocols can require that a
specific character encoding scheme is to be assumed if the optional
charset parameter is not specified, or they can require that the
charset parameter is used in certain cases. Such requirements are
not defined by this document.
Implementations that support binary source text MUST support binary
source text encoded using the UTF-8 [RFC3629] character encoding
scheme. Module goal sources MUST be encoded as UTF-8; all other
encodings will fail. Script goal sources SHOULD be encoded as UTF-8;
EID 8041 (Verified) is as follows:Section: 4
Original Text:
Source goal sources SHOULD be encoded as UTF-8
Corrected Text:
Script goal sources SHOULD be encoded as UTF-8
Notes:
Section 3 says there are only two goals: Module and Script. That "Source goal" is a typo and should read "Script goal".
other character encoding schemes MAY be supported but are
discouraged. Whether U+FEFF is processed as a Byte Order Mark (BOM)
signature or not depends on the host environment and is not defined
by this document.
4.1. Charset Parameter
The charset parameter provides a means to specify the character
encoding scheme of binary source text. If present, the value of the
charset parameter MUST be a registered charset [CHARSETS] and is
considered valid if it matches the mime-charset production defined in
Section 2.3 of [RFC2978].
The charset parameter is only used when processing a Script goal
source; Module goal sources MUST always be processed as UTF-8.
4.2. Character Encoding Scheme Detection
It is possible that implementations cannot interoperably determine a
single character encoding scheme simply by complying with all
requirements of the applicable specifications. To foster
interoperability in such cases, the following algorithm is defined.
Implementations apply this algorithm until a single character
encoding scheme is determined.
1. If the binary source text is not already determined to be using a
Module goal and starts with a Unicode encoding form signature,
the signature determines the encoding. The following octet
sequences, at the very beginning of the binary source text, are
considered with their corresponding character encoding schemes:
+==================+==========+
| Leading sequence | Encoding |
+==================+==========+
| EF BB BF | UTF-8 |
+------------------+----------+
| FF FE | UTF-16LE |
+------------------+----------+
| FE FF | UTF-16BE |
+------------------+----------+
Table 1
Implementations of this step MUST use these octet sequences to
determine the character encoding scheme, even if the determined
scheme is not supported. If this step determines the character
encoding scheme, the octet sequence representing the Unicode
encoding form signature MUST be ignored when decoding the binary
source text.
2. Else, if a charset parameter is specified and its value is valid
and supported by the implementation, the value determines the
character encoding scheme.
3. Else, the character encoding scheme is assumed to be UTF-8.
If the character encoding scheme is determined to be UTF-8 through
any means other than step 1 as defined above and the binary source
text starts with the octet sequence EF BB BF, the octet sequence is
ignored when decoding the binary source text.
4.3. Character Encoding Scheme Error Handling
Binary source text that is not properly encoded for the determined
character encoding can pose a security risk, as discussed in
Section 5. That said, because of the varied and complex environments
scripts are executed in, most of the error handling specifics are
left to the processors. The following are broad guidelines that
processors follow.
If binary source text is determined to have been encoded using a
certain character encoding scheme that the implementation is unable
to process, implementations can consider the resource unsupported
(i.e., do not decode the binary source text using a different
character encoding scheme).
Binary source text can be determined to have been encoded using a
certain character encoding scheme but contain octet sequences that
are not valid according to that scheme. Implementations can
substitute those invalid sequences with the replacement character
U+FFFD (properly encoded for the scheme) or stop processing
altogether.
5. Security Considerations
Refer to [RFC3552] for a discussion of terminology used in this
section. Examples in this section and discussions of interactions of
host environments with scripts, modules, and extensions to [ECMA-262]
are to be understood as non-exhaustive and of a purely illustrative
nature.
The programming language defined in [ECMA-262] is not intended to be
computationally self-sufficient; rather, it is expected that the
computational environment provides facilities to programs to enable
specific functionality. Such facilities constitute unknown factors
and are thus not defined by this document.
Derived programming languages are permitted to include additional
functionality that is not described in [ECMA-262]; such functionality
constitutes an unknown factor and is thus not defined by this
document. In particular, extensions to [ECMA-262] defined for the
JavaScript programming language are not discussed in this document.
Uncontrolled execution of scripts can be exceedingly dangerous.
Implementations that execute scripts MUST give consideration to their
application's threat models and those of the individual features they
implement; in particular, they MUST ensure that untrusted content is
not executed in an unprotected environment.
Module scripts in ECMAScript can request the fetching and processing
of additional scripts; this is called "importing". Implementations
that support modules need to process imported sources in the same way
as scripts. See the section "ECMAScript Language: Scripts and
Modules" in [ECMA-262] for details. Further, there may be additional
privacy and security concerns, depending on the location(s) the
original script and its imported modules are obtained from. For
instance, a script obtained from "host-a.example" could request to
import a script from "host-b.example", which could expose information
about the executing environment (e.g., IP address) to "host-
b.example".
Specifications for host environment facilities and for derived
programming languages should include security considerations. If an
implementation supports such facilities, the respective security
considerations apply. In particular, if scripts can be referenced
from or included in specific document formats, the considerations for
the embedding or referencing document format apply.
For example, scripts embedded in application/xhtml+xml [RFC3236]
documents could be enabled through the host environment to manipulate
the document instance, which could cause the retrieval of remote
resources; security considerations regarding retrieval of remote
resources of the embedding document would apply in this case.
This circumstance can further be used to make information that is
normally only available to the script also available to a web server
by encoding the information in the resource identifier of the
resource, which can further enable eavesdropping attacks.
Implementation of such facilities is subject to the security
considerations of the host environment, as discussed above.
The programming language defined in [ECMA-262] does include
facilities to loop, cause computationally complex operations, or
consume large amounts of memory; this includes, but is not limited
to, facilities that allow dynamically generated source text to be
executed (e.g., the eval() function); uncontrolled execution of such
features can cause denial of service, which implementations MUST
protect against.
With the addition of SharedArrayBuffer objects in ECMAScript version
8, it could be possible to implement a high-resolution timer, which
could lead to certain types of timing and side-channel attacks (e.g.,
[SPECTRE]). Implementations can take steps to mitigate this concern,
such as disabling or removing support for SharedArrayBuffer objects,
or can take additional steps to ensure that this shared memory is
only accessible between execution contexts that have some form of
mutual trust.
A host environment can provide facilities to access external input.
Scripts that pass such input to the eval() function or similar
language features can be vulnerable to code injection attacks.
Scripts are expected to protect against such attacks.
A host environment can provide facilities to output computed results
in a user-visible manner. For example, host environments supporting
a graphical user interface can provide facilities that enable scripts
to present certain messages to the user. Implementations MUST take
steps to avoid confusion of the origin of such messages. In general,
the security considerations for the host environment apply in such a
case as discussed above.
Implementations are required to support the UTF-8 character encoding
scheme; the security considerations of [RFC3629] apply. Additional
character encoding schemes may be supported; support for such schemes
is subject to the security considerations of those schemes.
Source text is expected to be in Unicode Normalization Form C.
Scripts and implementations MUST consider security implications of
unnormalized source text and data. For a detailed discussion of such
implications, refer to the security considerations in [RFC3629].
Scripts can be executed in an environment that is vulnerable to code
injection attacks. For example, a Common Gateway Interface (CGI)
script [RFC3875] echoing user input could allow the inclusion of
untrusted scripts that could be executed in an otherwise trusted
environment. This threat scenario is subject to security
considerations that are out of the scope of this document.
The "data" resource identifier scheme [RFC2397], in combination with
the types defined in this document, could be used to cause execution
of untrusted scripts through the inclusion of untrusted resource
identifiers in otherwise trusted content. Security considerations of
[RFC2397] apply.
Implementations can fail to implement a specific security model or
other means to prevent possibly dangerous operations. Such failure
could possibly be exploited to gain unauthorized access to a system
or sensitive information; such failure constitutes an unknown factor
and is thus not defined by this document.
6. IANA Considerations
The media type registrations herein are divided into two major
categories: (1) the sole media type "text/javascript", which is now
in common usage and (2) all of the media types that are obsolete
(i.e., "application/ecmascript", "application/javascript",
"application/x-ecmascript", "application/x-javascript", "text/
ecmascript", "text/javascript1.0", "text/javascript1.1", "text/
javascript1.2", "text/javascript1.3", "text/javascript1.4", "text/
javascript1.5", "text/jscript", "text/livescript", and "text/
x-ecmascript").
For both categories, the "Published specification" entry for the
media types is updated to reference [ECMA-262]. In addition, a new
file extension of .mjs has been added to the list of file extensions
with the restriction that contents should be parsed using the Module
goal. Finally, the [HTML] specification uses "text/javascript" as
the default media type of ECMAScript when preparing script tags;
therefore, "text/javascript" intended usage has been moved from
OBSOLETE to COMMON.
These changes have been reflected in the IANA "Media Types" registry
in accordance with [RFC6838]. All registrations will point to this
document as the reference. The outdated note stating that the "text/
javascript" media type has been "OBSOLETED in favor of application/
javascript" has been removed. The outdated note stating that the
"text/ecmascript" media type has been "OBSOLETED in favor of
application/ecmascript" has been removed. IANA has added the note
"OBSOLETED in favor of text/javascript" to all registrations except
"text/javascript"; that is, this note has been added to the "text/
ecmascript", "application/javascript", and "application/ecmascript"
registrations.
Four of the legacy media types in this document have a subtype
starting with the "x-" prefix:
* application/x-ecmascript
* application/x-javascript
* text/x-ecmascript
* text/x-javascript
Note that these are grandfathered media types registered as per
Appendix A of [RFC6838]. These registrations predate BCP 178
[RFC6648], which they violate, and are only included in this document
for backward compatibility.
6.1. Common JavaScript Media Types
6.1.1. text/javascript
Type name: text
Subtype name: javascript
Required parameters: N/A
Optional parameters: charset. See Section 4.1 of RFC 9239.
Encoding considerations: Binary
Security considerations: See Section 5 of RFC 9239.
Interoperability considerations: It is expected that implementations
will behave as if this registration applies to later editions of
[ECMA-262], and its published specification references may be
updated accordingly from time to time. Although this expectation
is unusual among media type registrations, it matches widespread
industry conventions. See Section 2 of RFC 9239.
Published specification: [ECMA-262]
Applications that use this media type: Script interpreters as
discussed in RFC 9239.
Additional information:
Deprecated alias names for this type: application/javascript,
application/x-javascript, text/javascript1.0, text/
javascript1.1, text/javascript1.2, text/javascript1.3, text/
javascript1.4, text/javascript1.5, text/jscript, text/
livescript
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 the
Authors' Addresses sections of RFC 9239 and [RFC4329].
Intended usage: COMMON
Restrictions on usage: The .mjs file extension signals that the file
represents a JavaScript module. Execution environments that rely
on file extensions to determine how to process inputs parse .mjs
files using the Module grammar of [ECMA-262].
Author: See the Authors' Addresses sections of RFC 9239 and
[RFC4329].
Change controller: IESG <iesg@ietf.org>
6.2. Historic JavaScript Media Types
The following media types and legacy aliases 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.
6.2.1. text/ecmascript
Type name: text
Subtype name: ecmascript
Required parameters: N/A
Optional parameters: charset. See Section 4.1 of RFC 9239.
Encoding considerations: Binary
Security considerations: See Section 5 of RFC 9239.
Interoperability considerations: It is expected that implementations
will behave as if this registration applies to later editions of
[ECMA-262], and its published specification references may be
updated accordingly from time to time. Although this expectation
is unusual among media type registrations, it matches widespread
industry conventions. See Section 2 of RFC 9239.
Published specification: [ECMA-262]
Applications that use this media type: Script interpreters as
discussed in RFC 9239.
Additional information:
Deprecated alias names for this type: application/ecmascript,
application/x-ecmascript, text/x-ecmascript
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 the
Authors' Addresses sections of RFC 9239 and [RFC4329].
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 .mjs file extension signals that the
file represents a JavaScript module. Execution environments that
rely on file extensions to determine how to process inputs parse
.mjs files using the Module grammar of [ECMA-262].
Author: See the Authors' Addresses sections of RFC 9239 and
[RFC4329].
Change controller: IESG <iesg@ietf.org>
7. References
7.1. Normative References
[CHARSETS] IANA, "Character Sets",
<https://www.iana.org/assignments/character-sets>.
[ECMA-262] Ecma International, "ECMA-262 12th Edition, June 2021.
ECMAScript 2021 language specification", June 2021,
<https://262.ecma-international.org/12.0/>.
[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,
<https://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,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2397] Masinter, L., "The "data" URL scheme", RFC 2397,
DOI 10.17487/RFC2397, August 1998,
<https://www.rfc-editor.org/info/rfc2397>.
[RFC2978] Freed, N. and J. Postel, "IANA Charset Registration
Procedures", BCP 19, RFC 2978, DOI 10.17487/RFC2978,
October 2000, <https://www.rfc-editor.org/info/rfc2978>.
[RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC
Text on Security Considerations", BCP 72, RFC 3552,
DOI 10.17487/RFC3552, July 2003,
<https://www.rfc-editor.org/info/rfc3552>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <https://www.rfc-editor.org/info/rfc3629>.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", RFC 4288, DOI 10.17487/RFC4288,
December 2005, <https://www.rfc-editor.org/info/rfc4288>.
[RFC4329] Hoehrmann, B., "Scripting Media Types", RFC 4329,
DOI 10.17487/RFC4329, April 2006,
<https://www.rfc-editor.org/info/rfc4329>.
[RFC6365] Hoffman, P. and J. Klensin, "Terminology Used in
Internationalization in the IETF", BCP 166, RFC 6365,
DOI 10.17487/RFC6365, September 2011,
<https://www.rfc-editor.org/info/rfc6365>.
[RFC6648] Saint-Andre, P., Crocker, D., and M. Nottingham,
"Deprecating the "X-" Prefix and Similar Constructs in
Application Protocols", BCP 178, RFC 6648,
DOI 10.17487/RFC6648, June 2012,
<https://www.rfc-editor.org/info/rfc6648>.
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type
Specifications and Registration Procedures", BCP 13,
RFC 6838, DOI 10.17487/RFC6838, January 2013,
<https://www.rfc-editor.org/info/rfc6838>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
7.2. Informative References
[HTML] WHATWG, "HTML Living Standard", May 2022,
<https://html.spec.whatwg.org/multipage/
scripting.html#prepare-a-script>.
[RFC3236] Baker, M. and P. Stark, "The 'application/xhtml+xml' Media
Type", RFC 3236, DOI 10.17487/RFC3236, January 2002,
<https://www.rfc-editor.org/info/rfc3236>.
[RFC3875] Robinson, D. and K. Coar, "The Common Gateway Interface
(CGI) Version 1.1", RFC 3875, DOI 10.17487/RFC3875,
October 2004, <https://www.rfc-editor.org/info/rfc3875>.
[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,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC3987] Duerst, M. and M. Suignard, "Internationalized Resource
Identifiers (IRIs)", RFC 3987, DOI 10.17487/RFC3987,
January 2005, <https://www.rfc-editor.org/info/rfc3987>.
[SPECTRE] Kocher, P., Genkin, D., Gruss, D., Haas, W., Hamburg, M.,
Lipp, M., Mangard, S., Prescher, T., Schwarz, M., and Y.
Yarom, "Spectre Attacks: Exploiting Speculative
Execution", DOI 10.48550/arXiv.1801.01203, January 2018,
<https://arxiv.org/abs/1801.01203>.
[TC39-MIME-ISSUE]
TC39, "Add 'application/javascript+module' mime to remove
ambiguity", Wayback Machine archive, August 2017, <https:/
/web.archive.org/web/20170814193912/https://github.com/
tc39/ecma262/issues/322>.
Appendix A. Changes from RFC 4329
* Added a section discussing ECMAScript modules and the impact on
processing.
* Updated the Security Considerations section to discuss concerns
associated with ECMAScript modules and SharedArrayBuffers.
* Updated the character encoding scheme detection to remove
normative guidance on its use, to better reflect operational
reality.
* Changed the intended usage of the media type "text/javascript"
from OBSOLETE to COMMON.
* Changed the intended usage for all other script media types to
obsolete.
* Updated various references where the original has been obsoleted.
* Updated references to ECMA-262 to match the version at the time of
publication.
Acknowledgements
This work builds upon its antecedent document, authored by Björn
Höhrmann. The authors would like to thank Adam Roach, Alexey
Melnikov, Allen Wirfs-Brock, Anne van Kesteren, Ben Campbell,
Benjamin Kaduk, Éric Vyncke, Francesca Palombini, James Snell, Kirsty
Paine, Mark Nottingham, Murray Kucherawy, Ned Freed, Robert Sparks,
and Suresh Krishnan for their guidance and feedback throughout this
process.
Authors' Addresses
Matthew A. Miller
Email: linuxwolf+ietf@outer-planes.net
Myles Borins
GitHub
Email: mylesborins@github.com
Mathias Bynens
Google
Email: mths@google.com
Bradley Farias
Email: bradley.meck@gmail.com