< draft-ietf-httpbis-content-disp-05.txt   draft-ietf-httpbis-content-disp-06.txt >
HTTPbis Working Group J. Reschke HTTPbis Working Group J. Reschke
Internet-Draft greenbytes Internet-Draft greenbytes
Updates: 2616 (if approved) February 17, 2011 Updates: 2616 (if approved) February 26, 2011
Intended status: Standards Track Intended status: Standards Track
Expires: August 21, 2011 Expires: August 30, 2011
Use of the Content-Disposition Header Field in the Use of the Content-Disposition Header Field in the
Hypertext Transfer Protocol (HTTP) Hypertext Transfer Protocol (HTTP)
draft-ietf-httpbis-content-disp-05 draft-ietf-httpbis-content-disp-06
Abstract Abstract
HTTP/1.1 defines the Content-Disposition response header field, but RFC 2616 defines the Content-Disposition response header field, but
points out that it is not part of the HTTP/1.1 Standard. This points out that it is not part of the HTTP/1.1 Standard. This
specification takes over the definition and registration of Content- specification takes over the definition and registration of Content-
Disposition, as used in HTTP, and clarifies internationalization Disposition, as used in HTTP, and clarifies internationalization
aspects. aspects.
Editorial Note (To be removed by RFC Editor before publication) Editorial Note (To be removed by RFC Editor before publication)
This specification is expected to replace the definition of Content- This specification is expected to replace the definition of Content-
Disposition in the HTTP/1.1 specification, as currently revised by Disposition in the HTTP/1.1 specification, as currently revised by
the IETF HTTPbis working group. See also the IETF HTTPbis working group. See also
<http://trac.tools.ietf.org/wg/httpbis/trac/ticket/123>. <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/123>.
Discussion of this draft should take place on the HTTPBIS working Discussion of this draft should take place on the HTTPBIS working
group mailing list (ietf-http-wg@w3.org). The current issues list is group mailing list (ietf-http-wg@w3.org). The current issues list is
at <http://trac.tools.ietf.org/wg/httpbis/trac/ at <http://trac.tools.ietf.org/wg/httpbis/trac/
query?component=content-disp> and related documents (including fancy query?component=content-disp> and related documents (including fancy
diffs) can be found at <http://tools.ietf.org/wg/httpbis/>. diffs) can be found at <http://tools.ietf.org/wg/httpbis/>.
The changes in this draft are summarized in Appendix D.9. The changes in this draft are summarized in Appendix E.10.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 21, 2011. This Internet-Draft will expire on August 30, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 3, line 16 skipping to change at page 3, line 16
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Notational Conventions . . . . . . . . . . . . . . . . . . . . 4 2. Notational Conventions . . . . . . . . . . . . . . . . . . . . 4
3. Conformance and Error Handling . . . . . . . . . . . . . . . . 4 3. Conformance and Error Handling . . . . . . . . . . . . . . . . 4
4. Header Field Definition . . . . . . . . . . . . . . . . . . . 5 4. Header Field Definition . . . . . . . . . . . . . . . . . . . 5
4.1. Grammar . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.1. Grammar . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2. Disposition Type . . . . . . . . . . . . . . . . . . . . . 6 4.2. Disposition Type . . . . . . . . . . . . . . . . . . . . . 6
4.3. Disposition Parameter: 'Filename' . . . . . . . . . . . . 6 4.3. Disposition Parameter: 'Filename' . . . . . . . . . . . . 6
4.4. Disposition Parameter: Extensions . . . . . . . . . . . . 7 4.4. Disposition Parameter: Extensions . . . . . . . . . . . . 7
4.5. Extensibility . . . . . . . . . . . . . . . . . . . . . . 7 4.5. Extensibility . . . . . . . . . . . . . . . . . . . . . . 7
5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Internationalization Considerations . . . . . . . . . . . . . 8 6. Internationalization Considerations . . . . . . . . . . . . . 8
7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 7. Security Considerations . . . . . . . . . . . . . . . . . . . 9
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8.1. Registry for Disposition Values and Parameter . . . . . . 9 8.1. Registry for Disposition Values and Parameter . . . . . . 9
8.2. Header Field Registration . . . . . . . . . . . . . . . . 9 8.2. Header Field Registration . . . . . . . . . . . . . . . . 9
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9
10.1. Normative References . . . . . . . . . . . . . . . . . . . 9 10.1. Normative References . . . . . . . . . . . . . . . . . . . 9
10.2. Informative References . . . . . . . . . . . . . . . . . . 10 10.2. Informative References . . . . . . . . . . . . . . . . . . 10
Appendix A. Changes from the RFC 2616 Definition . . . . . . . . 10 Appendix A. Changes from the RFC 2616 Definition . . . . . . . . 10
Appendix B. Differences compared to RFC 2183 . . . . . . . . . . 11 Appendix B. Differences compared to RFC 2183 . . . . . . . . . . 11
Appendix C. Alternative Approaches to Internationalization . . . 11 Appendix C. Alternative Approaches to Internationalization . . . 11
C.1. RFC 2047 Encoding . . . . . . . . . . . . . . . . . . . . 11 C.1. RFC 2047 Encoding . . . . . . . . . . . . . . . . . . . . 11
C.2. Percent Encoding . . . . . . . . . . . . . . . . . . . . . 12 C.2. Percent Encoding . . . . . . . . . . . . . . . . . . . . . 12
C.3. Encoding Sniffing . . . . . . . . . . . . . . . . . . . . 12 C.3. Encoding Sniffing . . . . . . . . . . . . . . . . . . . . 12
C.4. Implementations (to be removed by RFC Editor before C.4. Implementations (to be removed by RFC Editor before
publication) . . . . . . . . . . . . . . . . . . . . . . . 12 publication) . . . . . . . . . . . . . . . . . . . . . . . 12
Appendix D. Change Log (to be removed by RFC Editor before Appendix D. Advice on Generating Content-Disposition Header
publication) . . . . . . . . . . . . . . . . . . . . 13 Fields . . . . . . . . . . . . . . . . . . . . . . . 13
D.1. Since draft-reschke-rfc2183-in-http-00 . . . . . . . . . . 13 Appendix E. Change Log (to be removed by RFC Editor before
D.2. Since draft-reschke-rfc2183-in-http-01 . . . . . . . . . . 13 publication) . . . . . . . . . . . . . . . . . . . . 14
D.3. Since draft-reschke-rfc2183-in-http-02 . . . . . . . . . . 13 E.1. Since draft-reschke-rfc2183-in-http-00 . . . . . . . . . . 14
D.4. Since draft-reschke-rfc2183-in-http-03 . . . . . . . . . . 13 E.2. Since draft-reschke-rfc2183-in-http-01 . . . . . . . . . . 14
D.5. Since draft-ietf-httpbis-content-disp-00 . . . . . . . . . 13 E.3. Since draft-reschke-rfc2183-in-http-02 . . . . . . . . . . 14
D.6. Since draft-ietf-httpbis-content-disp-01 . . . . . . . . . 13 E.4. Since draft-reschke-rfc2183-in-http-03 . . . . . . . . . . 15
D.7. Since draft-ietf-httpbis-content-disp-02 . . . . . . . . . 13 E.5. Since draft-ietf-httpbis-content-disp-00 . . . . . . . . . 15
D.8. Since draft-ietf-httpbis-content-disp-03 . . . . . . . . . 14 E.6. Since draft-ietf-httpbis-content-disp-01 . . . . . . . . . 15
D.9. Since draft-ietf-httpbis-content-disp-04 . . . . . . . . . 14 E.7. Since draft-ietf-httpbis-content-disp-02 . . . . . . . . . 15
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 E.8. Since draft-ietf-httpbis-content-disp-03 . . . . . . . . . 15
E.9. Since draft-ietf-httpbis-content-disp-04 . . . . . . . . . 16
E.10. Since draft-ietf-httpbis-content-disp-05 . . . . . . . . . 16
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction 1. Introduction
HTTP/1.1 defines the Content-Disposition response header field in RFC 2616 defines the Content-Disposition response header field in
Section 19.5.1 of [RFC2616], but points out that it is not part of Section 19.5.1 of [RFC2616], but points out that it is not part of
the HTTP/1.1 Standard (Section 15.5): the HTTP/1.1 Standard (Section 15.5):
Content-Disposition is not part of the HTTP standard, but since it Content-Disposition is not part of the HTTP standard, but since it
is widely implemented, we are documenting its use and risks for is widely implemented, we are documenting its use and risks for
implementers. implementers.
This specification takes over the definition and registration of This specification takes over the definition and registration of
Content-Disposition, as used in HTTP. Based on interoperability Content-Disposition, as used in HTTP. Based on interoperability
testing with existing User Agents, it fully defines a profile of the testing with existing User Agents, it fully defines a profile of the
features defined in the Multipurpose Internet Mail Extensions (MIME) features defined in the Multipurpose Internet Mail Extensions (MIME)
variant ([RFC2183]) of the header field, and also clarifies variant ([RFC2183]) of the header field, and also clarifies
internationalization aspects. internationalization aspects.
Note: this document does not apply to Content-Disposition header Note: this document does not apply to Content-Disposition header
fields appearing in message payloads transmitted over HTTP, such fields appearing in payload bodies transmitted over HTTP, such as
as when using the media type "multipart/form-data" ([RFC2388]). when using the media type "multipart/form-data" ([RFC2388]).
2. Notational Conventions 2. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
This specification uses the augmented BNF notation defined in Section This specification uses the augmented BNF notation defined in Section
2.1 of [RFC2616], including its rules for implied linear whitespace 2.1 of [RFC2616], including its rules for implied linear whitespace
(LWS). (LWS).
3. Conformance and Error Handling 3. Conformance and Error Handling
This specification defines conformance criteria for both senders This specification defines conformance criteria for both senders
(usually, HTTP origin servers) and recipients (usually, HTTP user (usually, HTTP origin servers) and recipients (usually, HTTP user
agents) of the Content-Location header field. An implementation is agents) of the Content-Disposition header field. An implementation
considered conformant if it complies with all of the requirements is considered conformant if it complies with all of the requirements
associated with its role. associated with its role.
This specification also defines certain forms of the header field- This specification also defines certain forms of the header field-
value to be invalid, using both ABNF and prose requirements, but it value to be invalid, using both ABNF and prose requirements, but it
does not define special handling of these invalid field-values. does not define special handling of these invalid field-values.
Sending implementations MUST NOT generate Content-Location header Senders MUST NOT generate Content-Disposition header fields that are
fields that are invalid. invalid.
Consuming implementations MAY take steps to recover a usable field- Recipients MAY take steps to recover a usable field-value from an
value from an invalid header field, but SHOULD NOT reject the message invalid header field, but SHOULD NOT reject the message outright,
outright, unless this is explicitly desirable behaviour (e.g., the unless this is explicitly desirable behaviour (e.g., the
implementation is a validator). As such, the default handling of implementation is a validator). As such, the default handling of
invalid fields is to ignore them. invalid fields is to ignore them.
4. Header Field Definition 4. Header Field Definition
The Content-Disposition response header field is used to convey The Content-Disposition response header field is used to convey
additional information about how to process the response payload, and additional information about how to process the response payload, and
also can be used to attach additional metadata, such as the filename also can be used to attach additional metadata, such as the filename
to use when saving the response payload locally. to use when saving the response payload locally.
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of [RFC2616]), OPTIONAL whitespace can appear between words (token or of [RFC2616]), OPTIONAL whitespace can appear between words (token or
quoted-string) and separator characters. quoted-string) and separator characters.
Furthermore note that the format used for ext-value allows specifying Furthermore note that the format used for ext-value allows specifying
a natural language; this is of limited use for filenames and is a natural language; this is of limited use for filenames and is
likely to be ignored by recipients. likely to be ignored by recipients.
4.2. Disposition Type 4.2. Disposition Type
If the disposition type matches "attachment" (case-insensitively), If the disposition type matches "attachment" (case-insensitively),
this indicates that the user agent should prompt the user to save the this indicates that the recipient should prompt the user to save the
response locally, rather than process it normally (as per its media response locally, rather than process it normally (as per its media
type). type).
On the other hand, if it matches "inline" (case-insensitively), this On the other hand, if it matches "inline" (case-insensitively), this
implies default processing. implies default processing. Therefore, the disposition type "inline"
is only useful when it is augmented with additional parameters, such
as the filename (see below).
Unknown or unhandled disposition types SHOULD be handled by Unknown or unhandled disposition types SHOULD be handled by
recipients the same way as "attachment" (see also [RFC2183], Section recipients the same way as "attachment" (see also [RFC2183], Section
2.8). 2.8).
4.3. Disposition Parameter: 'Filename' 4.3. Disposition Parameter: 'Filename'
The parameters "filename" and "filename*", to be matched case- The parameters "filename" and "filename*", to be matched case-
insensitively, provide information on how to construct a filename for insensitively, provide information on how to construct a filename for
storing the message payload. storing the message payload.
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Many user agent implementations predating this specification do not Many user agent implementations predating this specification do not
understand the "filename*" parameter. Therefore, when both understand the "filename*" parameter. Therefore, when both
"filename" and "filename*" are present in a single header field "filename" and "filename*" are present in a single header field
value, recipients SHOULD pick "filename*" and ignore "filename". value, recipients SHOULD pick "filename*" and ignore "filename".
This way, senders can avoid special-casing specific user agents by This way, senders can avoid special-casing specific user agents by
sending both the more expressive "filename*" parameter, and the sending both the more expressive "filename*" parameter, and the
"filename" parameter as fallback for legacy recipients (see Section 5 "filename" parameter as fallback for legacy recipients (see Section 5
for an example). for an example).
It is essential that user agents treat the specified filename as It is essential that recipients treat the specified filename as
advisory only, thus be very careful in extracting the desired advisory only, thus be very careful in extracting the desired
information. In particular: information. In particular:
o When the value contains path separator characters ("\" or "/"), o When the value contains path separator characters ("\" or "/"),
recipients SHOULD ignore all but the last path segment. This recipients SHOULD ignore all but the last path segment. This
prevents unintentional overwriting of well-known file system prevents unintentional overwriting of well-known file system
locations (such as "/etc/passwd"). locations (such as "/etc/passwd").
o Many platforms do not use Internet Media Types ([RFC2046]) to hold o Many platforms do not use Internet Media Types ([RFC2046]) to hold
type information in the file system, but rely on filename type information in the file system, but rely on filename
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o Recipients are advised to strip or replace character sequences o Recipients are advised to strip or replace character sequences
that are known to cause confusion both in user interfaces and in that are known to cause confusion both in user interfaces and in
filenames, such as control characters and leading and trailing filenames, such as control characters and leading and trailing
whitespace. whitespace.
o Other aspects recipients need to be aware of are names that have a o Other aspects recipients need to be aware of are names that have a
special meaning in the file system or in shell commands, such as special meaning in the file system or in shell commands, such as
"." and "..", "~", "|", and also device names. "." and "..", "~", "|", and also device names.
Note: Many user agents do not properly handle escape characters Note: Many user agents do not properly handle the escape character
when using the quoted-string form. Furthermore, some user agents "\" when using the quoted-string form. Furthermore, some user
erroneously try to perform unescaping of "percent" escapes (see agents erroneously try to perform unescaping of "percent" escapes
Appendix C.2), and thus might misinterpret filenames containing (see Appendix C.2), and thus might misinterpret filenames
the percent character followed by two hex digits. containing the percent character followed by two hex digits.
4.4. Disposition Parameter: Extensions 4.4. Disposition Parameter: Extensions
To enable future extensions, recipients SHOULD ignore unrecognized To enable future extensions, recipients SHOULD ignore unrecognized
parameters (see also [RFC2183], Section 2.8). parameters (see also [RFC2183], Section 2.8).
4.5. Extensibility 4.5. Extensibility
Note that Section 9 of [RFC2183] defines IANA registries both for Note that Section 9 of [RFC2183] defines IANA registries both for
disposition types and disposition parameters. This registry is disposition types and disposition parameters. This registry is
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Here, the encoding defined in [RFC5987] is also used to encode the Here, the encoding defined in [RFC5987] is also used to encode the
non-ISO-8859-1 character. non-ISO-8859-1 character.
Same as above, but adding the "filename" parameter for compatibility Same as above, but adding the "filename" parameter for compatibility
with user agents not implementing RFC 5987: with user agents not implementing RFC 5987:
Content-Disposition: attachment; Content-Disposition: attachment;
filename="EURO rates"; filename="EURO rates";
filename*=utf-8''%e2%82%ac%20rates filename*=utf-8''%e2%82%ac%20rates
Note: as of February 2011, those user agents that do not support the Note: those user agents that do not support the RFC 5987 encoding
RFC 5987 encoding ignore "filename*" when it occurs after "filename". ignore "filename*" when it occurs after "filename".
Unfortunately, some user agents that do support RFC 5987 do pick the
"filename" rather than the "filename*" parameter when it occurs
first; it is expected that this situation is going to improve soon.
6. Internationalization Considerations 6. Internationalization Considerations
The "filename*" parameter (Section 4.3), using the encoding defined The "filename*" parameter (Section 4.3), using the encoding defined
in [RFC5987], allows the server to transmit characters outside the in [RFC5987], allows the server to transmit characters outside the
ISO-8859-1 character set, and also to optionally specify the language ISO-8859-1 character set, and also to optionally specify the language
in use. in use.
Future parameters might also require internationalization, in which Future parameters might also require internationalization, in which
case the same encoding can be used. case the same encoding can be used.
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"Uniform Resource Identifier (URI): Generic Syntax", "Uniform Resource Identifier (URI): Generic Syntax",
STD 66, RFC 3986, January 2005. STD 66, RFC 3986, January 2005.
Appendix A. Changes from the RFC 2616 Definition Appendix A. Changes from the RFC 2616 Definition
Compared to Section 19.5.1 of [RFC2616], the following normative Compared to Section 19.5.1 of [RFC2616], the following normative
changes reflecting actual implementations have been made: changes reflecting actual implementations have been made:
o According to RFC 2616, the disposition type "attachment" only o According to RFC 2616, the disposition type "attachment" only
applies to content of type "application/octet-stream". This applies to content of type "application/octet-stream". This
restriction has been removed, because user agents in practice do restriction has been removed, because recipients in practice do
not check the content type, and it also discourages properly not check the content type, and it also discourages properly
declaring the media type. declaring the media type.
o RFC 2616 only allows "quoted-string" for the filename parameter. o RFC 2616 only allows "quoted-string" for the filename parameter.
This would be an exceptional parameter syntax, and also doesn't This would be an exceptional parameter syntax, and also doesn't
reflect actual use. reflect actual use.
o The definition for the disposition type "inline" ([RFC2183], o The definition for the disposition type "inline" ([RFC2183],
Section 2.1) has been re-added with a suggestion for its Section 2.1) has been re-added with a suggestion for its
processing. processing.
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| Chrome | yes | yes | yes | yes | | Chrome | yes | yes | yes | yes |
| Firefox | yes (*) | yes | no | yes | | Firefox | yes (*) | yes | no | yes |
| Internet | yes (**) | no | yes | no | | Internet | yes (**) | no | yes | no |
| Explorer | | | | | | Explorer | | | | |
| Konqueror | yes | no | no | no | | Konqueror | yes | no | no | no |
| Opera | yes | no | no | no | | Opera | yes | no | no | no |
| Safari | no | no | no | yes | | Safari | no | no | no | yes |
+---------------+------------+--------+--------------+--------------+ +---------------+------------+--------+--------------+--------------+
(*) Does not implement the fallback behavior to "filename" described (*) Does not implement the fallback behavior to "filename" described
in Section 4.3. in Section 4.3; a fix is planned for Firefox 5.
(**) Starting with IE9RC, but only implements UTF-8. (**) Starting with IE9RC, but only implements UTF-8.
Appendix D. Change Log (to be removed by RFC Editor before publication) Appendix D. Advice on Generating Content-Disposition Header Fields
To successfully interoperate with existing and future user agents,
senders of the Content-Disposition header field are advised to:
o Include a "filename" parameter when US-ASCII is sufficiently
expressive.
o Use the 'token' form of the filename parameter only when it does
not contain disallowed characters (e.g., spaces); in such cases,
the quoted-string form should be used.
o Avoid including the percent character followed by two hexadecimal
characters (e.g., %A9) in the filename parameter, since some
existing implementations consider it to be an escape character,
while others will pass it through unchanged.
o Avoid including the "\" character in the quoted-string form of the
filename parameter, as escaping is not implemented by some user
agents, and can be considered as an illegal path character.
o Avoid using non-ASCII characters in the filename parameter.
Although most existing implementations will decode them as ISO-
8859-1, some will apply heuristics to detect UTF-8, and thus might
fail on certain names.
o Include a "filename*" parameter where the desired filename cannot
be expressed faithfully using the "filename" form. Note that
legacy user agents will not process this, and will fall back to
using the "filename" parameter's content.
o When a "filename*" parameter is sent, to also generate a
"filename" parameter as a fallback for user agents that do not
support the "filename*" form, if possible. This can be done by
substituting characters with US-ASCII sequences (e.g., Unicode
character point U+00E4 (LATIN SMALL LETTER A WITH DIARESIS) by
"ae"). Note that this may not be possible in some locales.
o When a "filename" parameter is included as a fallback (as per
above), "filename" should occur first, due to parsing problems in
some existing implementations. [[fallbackbug: Firefox is known to
pick the wrong parameter; a bug fix is scheduled for Firefox 5.
--jre]]
o Use UTF-8 as the encoding of the "filename*" parameter, when
present, because at least one existing implementation only
implements that encoding.
Note that this advice is based upon UA behaviour at the time of
writing, and might be superseded.
<http://purl.org/NET/http/content-disposition-tests> provides an
overview of current levels of support in various implementations.
Appendix E. Change Log (to be removed by RFC Editor before publication)
Note: the issues names in the change log entries for Note: the issues names in the change log entries for
draft-reschke-rfc2183-in-http refer to <http://greenbytes.de/tech/ draft-reschke-rfc2183-in-http refer to <http://greenbytes.de/tech/
webdav/draft-reschke-rfc2183-in-http-issues.html>. webdav/draft-reschke-rfc2183-in-http-issues.html>.
D.1. Since draft-reschke-rfc2183-in-http-00 E.1. Since draft-reschke-rfc2183-in-http-00
Adjust terminology ("header" -> "header field"). Update rfc2231-in- Adjust terminology ("header" -> "header field"). Update rfc2231-in-
http reference. http reference.
D.2. Since draft-reschke-rfc2183-in-http-01 E.2. Since draft-reschke-rfc2183-in-http-01
Update rfc2231-in-http reference. Actually define the "filename" Update rfc2231-in-http reference. Actually define the "filename"
parameter. Add internationalization considerations. Add examples parameter. Add internationalization considerations. Add examples
using the RFC 5987 encoding. Add overview over other approaches, using the RFC 5987 encoding. Add overview over other approaches,
plus a table reporting implementation status. Add and resolve issue plus a table reporting implementation status. Add and resolve issue
"nodep2183". Add issues "asciivsiso", "deplboth", "quoted", and "nodep2183". Add issues "asciivsiso", "deplboth", "quoted", and
"registry". "registry".
D.3. Since draft-reschke-rfc2183-in-http-02 E.3. Since draft-reschke-rfc2183-in-http-02
Add and close issue "docfallback". Close issues "asciivsiso", Add and close issue "docfallback". Close issues "asciivsiso",
"deplboth", "quoted", and "registry". "deplboth", "quoted", and "registry".
D.4. Since draft-reschke-rfc2183-in-http-03 E.4. Since draft-reschke-rfc2183-in-http-03
Updated to be a Working Draft of the IETF HTTPbis Working Group. Updated to be a Working Draft of the IETF HTTPbis Working Group.
D.5. Since draft-ietf-httpbis-content-disp-00 E.5. Since draft-ietf-httpbis-content-disp-00
Closed issues: Closed issues:
o <http://tools.ietf.org/wg/httpbis/trac/ticket/242>: "handling of o <http://tools.ietf.org/wg/httpbis/trac/ticket/242>: "handling of
unknown disposition types" unknown disposition types"
Slightly updated the notes about the proposed fallback behavior. Slightly updated the notes about the proposed fallback behavior.
D.6. Since draft-ietf-httpbis-content-disp-01 E.6. Since draft-ietf-httpbis-content-disp-01
Various editorial improvements. Various editorial improvements.
D.7. Since draft-ietf-httpbis-content-disp-02 E.7. Since draft-ietf-httpbis-content-disp-02
Closed issues: Closed issues:
o <http://tools.ietf.org/wg/httpbis/trac/ticket/244>: "state that o <http://tools.ietf.org/wg/httpbis/trac/ticket/244>: "state that
repeating parameters are invalid" repeating parameters are invalid"
o <http://tools.ietf.org/wg/httpbis/trac/ticket/245>: "warn about o <http://tools.ietf.org/wg/httpbis/trac/ticket/245>: "warn about
%xx in filenames being misinterpreted" %xx in filenames being misinterpreted"
o <http://tools.ietf.org/wg/httpbis/trac/ticket/246>: "mention o <http://tools.ietf.org/wg/httpbis/trac/ticket/246>: "mention
control chars when talking about postprecessing the filename control chars when talking about postprecessing the filename
parameter" parameter"
Update Appendix C.4; Opera 10.63 RC implements the recommended Update Appendix C.4; Opera 10.63 RC implements the recommended
fallback behavior. fallback behavior.
D.8. Since draft-ietf-httpbis-content-disp-03 E.8. Since draft-ietf-httpbis-content-disp-03
Closed issues: Closed issues:
o <http://tools.ietf.org/wg/httpbis/trac/ticket/252>: o <http://tools.ietf.org/wg/httpbis/trac/ticket/252>:
"'modification-date' *is* implemented in Konq 4.5" "'modification-date' *is* implemented in Konq 4.5"
o <http://tools.ietf.org/wg/httpbis/trac/ticket/253>: "clarify what o <http://tools.ietf.org/wg/httpbis/trac/ticket/253>: "clarify what
LWS means for the Content-Disp grammar" LWS means for the Content-Disp grammar"
o <http://tools.ietf.org/wg/httpbis/trac/ticket/258>: "Avoid passive o <http://tools.ietf.org/wg/httpbis/trac/ticket/258>: "Avoid passive
skipping to change at page 14, line 40 skipping to change at page 16, line 14
o <http://tools.ietf.org/wg/httpbis/trac/ticket/263>: "text about o <http://tools.ietf.org/wg/httpbis/trac/ticket/263>: "text about
historical percent-decoding unclear" historical percent-decoding unclear"
o <http://tools.ietf.org/wg/httpbis/trac/ticket/264>: "add o <http://tools.ietf.org/wg/httpbis/trac/ticket/264>: "add
explanation of language tagging" explanation of language tagging"
o <http://tools.ietf.org/wg/httpbis/trac/ticket/265>: "Clarify that o <http://tools.ietf.org/wg/httpbis/trac/ticket/265>: "Clarify that
C-D spec does not apply to multipart upload" C-D spec does not apply to multipart upload"
D.9. Since draft-ietf-httpbis-content-disp-04 E.9. Since draft-ietf-httpbis-content-disp-04
Updated implementation information (Chrome 9 implements RFC 5987, IE Updated implementation information (Chrome 9 implements RFC 5987, IE
9 RC implements it for UTF-8 only). 9 RC implements it for UTF-8 only).
Clarify who requirements are on, add a section discussing conformance Clarify who requirements are on, add a section discussing conformance
and handling of invalid field values in general. and handling of invalid field values in general.
Closed issues: Closed issues:
o <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/243>: "avoid
stating ISO-8859-1 default for header param" (the default is still
mentioned, but it was clarified what it applies to).
o <http://tools.ietf.org/wg/httpbis/trac/ticket/272>: "Path o <http://tools.ietf.org/wg/httpbis/trac/ticket/272>: "Path
Separator Characters" Separator Characters"
E.10. Since draft-ietf-httpbis-content-disp-05
Editorial changes: Fixed two typos where the new Conformance section
said "Content-Location" instead of "Content-Disposition". Cleaned up
terminology ("user agent", "recipient", "sender", "message body",
...). Stated what the escape character for quoted-string is.
Explained a use case for "inline" disposition type. Updated
implementation notes with respect to the fallback behavior.
Added appendix "Advice on Generating Content-Disposition Header
Fields".
Index Index
C C
Content-Disposition header 5 Content-Disposition header field 5
H H
Headers Header Fields
Content-Disposition 5 Content-Disposition 5
Author's Address Author's Address
Julian F. Reschke Julian F. Reschke
greenbytes GmbH greenbytes GmbH
Hafenweg 16 Hafenweg 16
Muenster, NW 48155 Muenster, NW 48155
Germany Germany
 End of changes. 35 change blocks. 
57 lines changed or deleted 128 lines changed or added

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