One document matched: draft-ietf-httpbis-p2-semantics-11.xml
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<rfc obsoletes="2616" updates="2817" category="std" ipr="pre5378Trust200902" docName="draft-ietf-httpbis-p2-semantics-11">
<front>
<title abbrev="HTTP/1.1, Part 2">HTTP/1.1, part 2: Message Semantics</title>
<author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
<organization abbrev="Day Software">Day Software</organization>
<address>
<postal>
<street>23 Corporate Plaza DR, Suite 280</street>
<city>Newport Beach</city>
<region>CA</region>
<code>92660</code>
<country>USA</country>
</postal>
<phone>+1-949-706-5300</phone>
<facsimile>+1-949-706-5305</facsimile>
<email>fielding@gbiv.com</email>
<uri>http://roy.gbiv.com/</uri>
</address>
</author>
<author initials="J." surname="Gettys" fullname="Jim Gettys">
<organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
<address>
<postal>
<street>21 Oak Knoll Road</street>
<city>Carlisle</city>
<region>MA</region>
<code>01741</code>
<country>USA</country>
</postal>
<email>jg@freedesktop.org</email>
<uri>http://gettys.wordpress.com/</uri>
</address>
</author>
<author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
<organization abbrev="HP">Hewlett-Packard Company</organization>
<address>
<postal>
<street>HP Labs, Large Scale Systems Group</street>
<street>1501 Page Mill Road, MS 1177</street>
<city>Palo Alto</city>
<region>CA</region>
<code>94304</code>
<country>USA</country>
</postal>
<email>JeffMogul@acm.org</email>
</address>
</author>
<author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address>
<postal>
<street>1 Microsoft Way</street>
<city>Redmond</city>
<region>WA</region>
<code>98052</code>
<country>USA</country>
</postal>
<email>henrikn@microsoft.com</email>
</address>
</author>
<author initials="L." surname="Masinter" fullname="Larry Masinter">
<organization abbrev="Adobe Systems">Adobe Systems, Incorporated</organization>
<address>
<postal>
<street>345 Park Ave</street>
<city>San Jose</city>
<region>CA</region>
<code>95110</code>
<country>USA</country>
</postal>
<email>LMM@acm.org</email>
<uri>http://larry.masinter.net/</uri>
</address>
</author>
<author initials="P." surname="Leach" fullname="Paul J. Leach">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address>
<postal>
<street>1 Microsoft Way</street>
<city>Redmond</city>
<region>WA</region>
<code>98052</code>
</postal>
<email>paulle@microsoft.com</email>
</address>
</author>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
<address>
<postal>
<street>MIT Computer Science and Artificial Intelligence Laboratory</street>
<street>The Stata Center, Building 32</street>
<street>32 Vassar Street</street>
<city>Cambridge</city>
<region>MA</region>
<code>02139</code>
<country>USA</country>
</postal>
<email>timbl@w3.org</email>
<uri>http://www.w3.org/People/Berners-Lee/</uri>
</address>
</author>
<author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
<organization abbrev="W3C">World Wide Web Consortium</organization>
<address>
<postal>
<street>W3C / ERCIM</street>
<street>2004, rte des Lucioles</street>
<city>Sophia-Antipolis</city>
<region>AM</region>
<code>06902</code>
<country>France</country>
</postal>
<email>ylafon@w3.org</email>
<uri>http://www.raubacapeu.net/people/yves/</uri>
</address>
</author>
<author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
<organization abbrev="greenbytes">greenbytes GmbH</organization>
<address>
<postal>
<street>Hafenweg 16</street>
<city>Muenster</city><region>NW</region><code>48155</code>
<country>Germany</country>
</postal>
<phone>+49 251 2807760</phone>
<facsimile>+49 251 2807761</facsimile>
<email>julian.reschke@greenbytes.de</email>
<uri>http://greenbytes.de/tech/webdav/</uri>
</address>
</author>
<date month="August" year="2010" day="4"/>
<workgroup>HTTPbis Working Group</workgroup>
<abstract>
<t>
The Hypertext Transfer Protocol (HTTP) is an application-level
protocol for distributed, collaborative, hypermedia information
systems. HTTP has been in use by the World Wide Web global information
initiative since 1990. This document is Part 2 of the seven-part specification
that defines the protocol referred to as "HTTP/1.1" and, taken together,
obsoletes RFC 2616. Part 2 defines the semantics of HTTP messages
as expressed by request methods, request-header fields, response status codes,
and response-header fields.
</t>
</abstract>
<note title="Editorial Note (To be removed by RFC Editor)">
<t>
Discussion of this draft should take place on the HTTPBIS working group
mailing list (ietf-http-wg@w3.org). The current issues list is
at <eref target="http://tools.ietf.org/wg/httpbis/trac/report/3"/>
and related documents (including fancy diffs) can be found at
<eref target="http://tools.ietf.org/wg/httpbis/"/>.
</t>
<t>
The changes in this draft are summarized in <xref target="changes.since.10"/>.
</t>
</note>
</front>
<middle>
<section title="Introduction" anchor="introduction">
<t>
This document defines HTTP/1.1 request and response semantics. Each HTTP
message, as defined in <xref target="Part1"/>, is in the form of either a request or
a response. An HTTP server listens on a connection for HTTP requests and
responds to each request, in the order received on that connection, with
one or more HTTP response messages. This document defines the commonly
agreed upon semantics of the HTTP uniform interface, the intentions defined
by each request method, and the various response messages that might be
expected as a result of applying that method to the target resource.
</t>
<t>
This document is currently disorganized in order to minimize the changes
between drafts and enable reviewers to see the smaller errata changes.
The next draft will reorganize the sections to better reflect the content.
In particular, the sections will be ordered according to the typical
processing of an HTTP request message (after message parsing): resource
mapping, general header fields, methods, request modifiers, response
status, and resource metadata. The current mess reflects how widely
dispersed these topics and associated requirements had become in
<xref target="RFC2616"/>.
</t>
<section title="Requirements" anchor="intro.requirements">
<t>
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in <xref target="RFC2119"/>.
</t>
<t>
An implementation is not compliant if it fails to satisfy one or more
of the "MUST" or "REQUIRED" level requirements for the protocols it
implements. An implementation that satisfies all the "MUST" or "REQUIRED"
level and all the "SHOULD" level requirements for its protocols is said
to be "unconditionally compliant"; one that satisfies all the "MUST"
level requirements but not all the "SHOULD" level requirements for its
protocols is said to be "conditionally compliant".
</t>
</section>
<section title="Syntax Notation" anchor="notation">
<t>
This specification uses the ABNF syntax defined in Section 1.2 of <xref target="Part1"/> (which
extends the syntax defined in <xref target="RFC5234"/> with a list rule).
<xref target="collected.abnf"/> shows the collected ABNF, with the list
rule expanded.
</t>
<t>
The following core rules are included by
reference, as defined in <xref target="RFC5234"/>, Appendix B.1:
ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls),
DIGIT (decimal 0-9), DQUOTE (double quote),
HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed),
OCTET (any 8-bit sequence of data), SP (space),
VCHAR (any visible USASCII character),
and WSP (whitespace).
</t>
<section title="Core Rules" anchor="core.rules">
<t>
The core rules below are defined in Section 1.2.2 of <xref target="Part1"/>:
</t>
<figure><artwork type="abnf2616"><![CDATA[
quoted-string = <quoted-string, defined in [Part1], Section 1.2.2>
token = <token, defined in [Part1], Section 1.2.2>
OWS = <OWS, defined in [Part1], Section 1.2.2>
RWS = <RWS, defined in [Part1], Section 1.2.2>
obs-text = <obs-text, defined in [Part1], Section 1.2.2>
]]></artwork></figure>
</section>
<section title="ABNF Rules defined in other Parts of the Specification" anchor="abnf.dependencies">
<t>
The ABNF rules below are defined in other parts:
</t>
<figure><artwork type="abnf2616"><![CDATA[
absolute-URI = <absolute-URI, defined in [Part1], Section 2.6>
comment = <comment, defined in [Part1], Section 3.2>
Host = <Host, defined in [Part1], Section 2.6>
HTTP-date = <HTTP-date, defined in [Part1], Section 6.1>
partial-URI = <partial-URI, defined in [Part1], Section 2.6>
product = <product, defined in [Part1], Section 6.3>
TE = <TE, defined in [Part1], Section 9.5>
URI-reference = <URI-reference, defined in [Part1], Section 2.6>
]]></artwork></figure>
<figure><artwork type="abnf2616"><![CDATA[
Accept = <Accept, defined in [Part3], Section 6.1>
Accept-Charset =
<Accept-Charset, defined in [Part3], Section 6.2>
Accept-Encoding =
<Accept-Encoding, defined in [Part3], Section 6.3>
Accept-Language =
<Accept-Language, defined in [Part3], Section 6.4>
]]></artwork></figure>
<figure><artwork type="abnf2616"><![CDATA[
ETag = <ETag, defined in [Part4], Section 6.1>
If-Match = <If-Match, defined in [Part4], Section 6.2>
If-Modified-Since =
<If-Modified-Since, defined in [Part4], Section 6.3>
If-None-Match = <If-None-Match, defined in [Part4], Section 6.4>
If-Unmodified-Since =
<If-Unmodified-Since, defined in [Part4], Section 6.5>
]]></artwork></figure>
<figure><artwork type="abnf2616"><![CDATA[
Accept-Ranges = <Accept-Ranges, defined in [Part5], Section 5.1>
If-Range = <If-Range, defined in [Part5], Section 5.3>
Range = <Range, defined in [Part5], Section 5.4>
]]></artwork></figure>
<figure><artwork type="abnf2616"><![CDATA[
Age = <Age, defined in [Part6], Section 3.1>
Vary = <Vary, defined in [Part6], Section 3.5>
]]></artwork></figure>
<figure><artwork type="abnf2616"><![CDATA[
Authorization = <Authorization, defined in [Part7], Section 3.1>
Proxy-Authenticate =
<Proxy-Authenticate, defined in [Part7], Section 3.2>
Proxy-Authorization =
<Proxy-Authorization, defined in [Part7], Section 3.3>
WWW-Authenticate =
<WWW-Authenticate, defined in [Part7], Section 3.4>
]]></artwork></figure>
</section>
</section>
</section>
<section title="Method" anchor="method">
<t>
The Method token indicates the method to be performed on the target
resource (Section 4.3 of <xref target="Part1"/>). The method is case-sensitive.
</t>
<figure><iref primary="true" item="Grammar" subitem="Method"/><iref primary="true" item="Grammar" subitem="extension-method"/><artwork type="abnf2616"><![CDATA[
Method = %x4F.50.54.49.4F.4E.53 ; "OPTIONS", Section 7.2
/ %x47.45.54 ; "GET", Section 7.3
/ %x48.45.41.44 ; "HEAD", Section 7.4
/ %x50.4F.53.54 ; "POST", Section 7.5
/ %x50.55.54 ; "PUT", Section 7.6
/ %x44.45.4C.45.54.45 ; "DELETE", Section 7.7
/ %x54.52.41.43.45 ; "TRACE", Section 7.8
/ %x43.4F.4E.4E.45.43.54 ; "CONNECT", Section 7.9
/ extension-method
extension-method = token
]]></artwork></figure>
<t>
The list of methods allowed by a resource can be specified in an
Allow header field (<xref target="header.allow"/>). The status code of the response
always notifies the client whether a method is currently allowed on a
resource, since the set of allowed methods can change dynamically. An
origin server SHOULD respond with the status code 405 (Method Not Allowed)
if the method is known by the origin server but not allowed for the
resource, and 501 (Not Implemented) if the method is
unrecognized or not implemented by the origin server. The methods GET
and HEAD MUST be supported by all general-purpose servers. All other
methods are OPTIONAL; however, if the above methods are implemented,
they MUST be implemented with the same semantics as those specified
in <xref target="method.definitions"/>.
</t>
<section title="Method Registry" anchor="method.registry">
<t>
The HTTP Method Registry defines the name space for the Method token in the
Request line of an HTTP request.
</t>
<t>
Registrations MUST include the following fields:
<list style="symbols">
<t>Method Name (see <xref target="method"/>)</t>
<t>Safe ("yes" or "no", see <xref target="safe.methods"/>)</t>
<t>Pointer to specification text</t>
</list>
</t>
<t>
Values to be added to this name space are subject to IETF review
(<xref target="RFC5226"/>, Section 4.1).
</t>
<t>
The registry itself is maintained at <eref target="http://www.iana.org/assignments/http-methods"/>.
</t>
</section>
</section>
<section title="Request Header Fields" anchor="request.header.fields">
<t>
The request-header fields allow the client to pass additional
information about the request, and about the client itself, to the
server. These fields act as request modifiers, with semantics
equivalent to the parameters on a programming language method
invocation.
</t>
<figure><iref primary="true" item="Grammar" subitem="request-header"/><artwork type="abnf2616"><![CDATA[
request-header = Accept ; [Part3], Section 6.1
/ Accept-Charset ; [Part3], Section 6.2
/ Accept-Encoding ; [Part3], Section 6.3
/ Accept-Language ; [Part3], Section 6.4
/ Authorization ; [Part7], Section 3.1
/ Expect ; Section 9.2
/ From ; Section 9.3
/ Host ; [Part1], Section 9.4
/ If-Match ; [Part4], Section 6.2
/ If-Modified-Since ; [Part4], Section 6.3
/ If-None-Match ; [Part4], Section 6.4
/ If-Range ; [Part5], Section 5.3
/ If-Unmodified-Since ; [Part4], Section 6.5
/ Max-Forwards ; Section 9.5
/ Proxy-Authorization ; [Part7], Section 3.3
/ Range ; [Part5], Section 5.4
/ Referer ; Section 9.6
/ TE ; [Part1], Section 9.5
/ User-Agent ; Section 9.9
]]></artwork></figure>
<t>
Request-header field names can be extended reliably only in
combination with a change in the protocol version. However, new or
experimental header fields MAY be given the semantics of request-header
fields if all parties in the communication recognize them to
be request-header fields.
</t>
</section>
<section title="Status Code and Reason Phrase" anchor="status.code.and.reason.phrase">
<t>
The Status-Code element is a 3-digit integer result code of the
attempt to understand and satisfy the request. The status codes listed
below are defined in <xref target="status.codes"/>, Section 3 of <xref target="Part4"/>,
Section 3 of <xref target="Part5"/>, and Section 2 of <xref target="Part7"/>.
</t>
<t>
The Reason-Phrase is intended to give a short
textual description of the Status-Code. The Status-Code is intended
for use by automata and the Reason-Phrase is intended for the human
user. The client is not required to examine or display the Reason-Phrase.
</t>
<t>
The individual values of the numeric status codes defined for
HTTP/1.1, and an example set of corresponding Reason-Phrase values, are
presented below. The reason phrases listed here are only
recommendations -- they MAY be replaced by local equivalents without
affecting the protocol.
</t>
<figure><iref primary="true" item="Grammar" subitem="Status-Code"/><iref primary="true" item="Grammar" subitem="extension-code"/><iref primary="true" item="Grammar" subitem="Reason-Phrase"/><artwork type="abnf2616"><![CDATA[
Status-Code =
"100" ; Section 8.1.1: Continue
/ "101" ; Section 8.1.2: Switching Protocols
/ "200" ; Section 8.2.1: OK
/ "201" ; Section 8.2.2: Created
/ "202" ; Section 8.2.3: Accepted
/ "203" ; Section 8.2.4: Non-Authoritative Information
/ "204" ; Section 8.2.5: No Content
/ "205" ; Section 8.2.6: Reset Content
/ "206" ; [Part5], Section 3.1: Partial Content
/ "300" ; Section 8.3.1: Multiple Choices
/ "301" ; Section 8.3.2: Moved Permanently
/ "302" ; Section 8.3.3: Found
/ "303" ; Section 8.3.4: See Other
/ "304" ; [Part4], Section 3.1: Not Modified
/ "305" ; Section 8.3.6: Use Proxy
/ "307" ; Section 8.3.8: Temporary Redirect
/ "400" ; Section 8.4.1: Bad Request
/ "401" ; [Part7], Section 2.1: Unauthorized
/ "402" ; Section 8.4.3: Payment Required
/ "403" ; Section 8.4.4: Forbidden
/ "404" ; Section 8.4.5: Not Found
/ "405" ; Section 8.4.6: Method Not Allowed
/ "406" ; Section 8.4.7: Not Acceptable
/ "407" ; [Part7], Section 2.2: Proxy Authentication Required
/ "408" ; Section 8.4.9: Request Time-out
/ "409" ; Section 8.4.10: Conflict
/ "410" ; Section 8.4.11: Gone
/ "411" ; Section 8.4.12: Length Required
/ "412" ; [Part4], Section 3.2: Precondition Failed
/ "413" ; Section 8.4.14: Request Entity Too Large
/ "414" ; Section 8.4.15: URI Too Long
/ "415" ; Section 8.4.16: Unsupported Media Type
/ "416" ; [Part5], Section 3.2: Requested range not satisfiable
/ "417" ; Section 8.4.18: Expectation Failed
/ "500" ; Section 8.5.1: Internal Server Error
/ "501" ; Section 8.5.2: Not Implemented
/ "502" ; Section 8.5.3: Bad Gateway
/ "503" ; Section 8.5.4: Service Unavailable
/ "504" ; Section 8.5.5: Gateway Time-out
/ "505" ; Section 8.5.6: HTTP Version not supported
/ extension-code
extension-code = 3DIGIT
Reason-Phrase = *( WSP / VCHAR / obs-text )
]]></artwork></figure>
<t>
HTTP status codes are extensible. HTTP applications are not required
to understand the meaning of all registered status codes, though such
understanding is obviously desirable. However, applications MUST
understand the class of any status code, as indicated by the first
digit, and treat any unrecognized response as being equivalent to the
x00 status code of that class, with the exception that an
unrecognized response MUST NOT be cached. For example, if an
unrecognized status code of 431 is received by the client, it can
safely assume that there was something wrong with its request and
treat the response as if it had received a 400 status code. In such
cases, user agents SHOULD present to the user the representation enclosed
with the response, since that representation is likely to include human-readable
information which will explain the unusual status.
</t>
<section title="Status Code Registry" anchor="status.code.registry">
<t>
The HTTP Status Code Registry defines the name space for the Status-Code
token in the Status-Line of an HTTP response.
</t>
<t>
Values to be added to this name space are subject to IETF review
(<xref target="RFC5226"/>, Section 4.1).
</t>
<t>
The registry itself is maintained at <eref target="http://www.iana.org/assignments/http-status-codes"/>.
</t>
</section>
</section>
<section title="Response Header Fields" anchor="response.header.fields">
<t>
The response-header fields allow the server to pass additional
information about the response which cannot be placed in the Status-Line.
These header fields give information about the server and about
further access to the target resource (Section 4.3 of <xref target="Part1"/>).
</t>
<figure><iref primary="true" item="Grammar" subitem="response-header"/><artwork type="abnf2616"><![CDATA[
response-header = Accept-Ranges ; [Part5], Section 5.1
/ Age ; [Part6], Section 3.1
/ Allow ; Section 9.1
/ ETag ; [Part4], Section 6.1
/ Location ; Section 9.4
/ Proxy-Authenticate ; [Part7], Section 3.2
/ Retry-After ; Section 9.7
/ Server ; Section 9.8
/ Vary ; [Part6], Section 3.5
/ WWW-Authenticate ; [Part7], Section 3.4
]]></artwork></figure>
<t>
Response-header field names can be extended reliably only in
combination with a change in the protocol version. However, new or
experimental header fields MAY be given the semantics of response-header
fields if all parties in the communication recognize them to
be response-header fields.
</t>
</section>
<section title="Representation" anchor="representation">
<t>
Request and Response messages MAY transfer a representation if not otherwise
restricted by the request method or response status code. A representation
consists of metadata (representation header fields) and data (representation
body). When a complete or partial representation is enclosed in an HTTP message,
it is referred to as the payload of the message. HTTP representations
are defined in <xref target="Part3"/>.
</t>
<t>
A representation body is only present in a message when a message-body is
present, as described in Section 3.3 of <xref target="Part1"/>. The representation body is obtained
from the message-body by decoding any Transfer-Encoding that might
have been applied to ensure safe and proper transfer of the message.
</t>
<section title="Identifying the Resource Associated with a Representation" anchor="identifying.response.associated.with.representation">
<t>
It is sometimes necessary to determine an identifier for the resource
associated with a representation.
</t>
<t>
An HTTP request representation, when present, is always associated with an
anonymous (i.e., unidentified) resource.
</t>
<t>
In the common case, an HTTP response is a representation of the target
resource (see Section 4.3 of <xref target="Part1"/>). However, this is not always the
case. To determine the URI of the resource a response is associated with,
the following rules are used (with the first applicable one being selected):
</t>
<t><list style="numbers">
<t>If the response status code is 200 or 203 and the request method was GET,
the response payload is a representation of the target resource.</t>
<t>If the response status code is 204, 206, or 304 and the request method was GET
or HEAD, the response payload is a partial representation of the target
(see Section 2.8 of <xref target="Part6"/>).</t>
<t>If the response has a Content-Location header, and that URI is the same
as the effective request URI, the response payload is a representation of the
target resource.</t>
<t>If the response has a Content-Location header, and that URI is not the
same as the effective request URI, then the response asserts that its
payload is a representation of the resource identified by the
Content-Location URI. However, such an assertion cannot be trusted unless
it can be verified by other means (not defined by HTTP).</t>
<t>Otherwise, the response is a representation of an anonymous (i.e.,
unidentified) resource.</t>
</list></t>
<t>
<cref anchor="TODO-req-uri">
The comparison function is going to have to be defined somewhere,
because we already need to compare URIs for things like cache invalidation.</cref>
</t>
</section>
</section>
<section title="Method Definitions" anchor="method.definitions">
<t>
The set of common methods for HTTP/1.1 is defined below. Although
this set can be expanded, additional methods cannot be assumed to
share the same semantics for separately extended clients and servers.
</t>
<section title="Safe and Idempotent Methods" anchor="safe.and.idempotent">
<section title="Safe Methods" anchor="safe.methods">
<iref item="Safe Methods" primary="true"/>
<t>
Implementors need to be aware that the software represents the user in
their interactions over the Internet, and need to allow
the user to be aware of any actions they take which might have an
unexpected significance to themselves or others.
</t>
<t>
In particular, the convention has been established that the GET, HEAD,
OPTIONS, and TRACE methods SHOULD NOT have the significance of taking an action
other than retrieval. These methods ought to be considered "safe".
This allows user agents to represent other methods, such as POST, PUT
and DELETE, in a special way, so that the user is made aware of the
fact that a possibly unsafe action is being requested.
</t>
<t>
Naturally, it is not possible to ensure that the server does not
generate side-effects as a result of performing a GET request; in
fact, some dynamic resources consider that a feature. The important
distinction here is that the user did not request the side-effects,
so therefore cannot be held accountable for them.
</t>
</section>
<section title="Idempotent Methods" anchor="idempotent.methods">
<iref item="Idempotent Methods" primary="true"/>
<t>
Methods can also have the property of "idempotence" in that, aside
from error or expiration issues, the intended effect of multiple
identical requests is the same as for a single request.
The methods PUT, DELETE, and all safe methods are idempotent.
It is important to note that idempotence refers only to changes
requested by the client: a server is free to change its state due
to multiple requests for the purpose of tracking those requests,
versioning of results, etc.
</t>
</section>
</section>
<section title="OPTIONS" anchor="OPTIONS">
<iref primary="true" item="OPTIONS method"/>
<iref primary="true" item="Methods" subitem="OPTIONS"/>
<t>
The OPTIONS method represents a request for information about the
communication options available on the request/response chain
identified by the effective request URI. This method allows the client to
determine the options and/or requirements associated with a resource,
or the capabilities of a server, without implying a resource action
or initiating a resource retrieval.
</t>
<t>
Responses to this method are not cacheable.
</t>
<t>
If the OPTIONS request includes a message-body (as indicated by the
presence of Content-Length or Transfer-Encoding), then the media type
MUST be indicated by a Content-Type field. Although this
specification does not define any use for such a body, future
extensions to HTTP might use the OPTIONS body to make more detailed
queries on the server.
</t>
<t>
If the request-target is an asterisk ("*"), the OPTIONS request is
intended to apply to the server in general rather than to a specific
resource. Since a server's communication options typically depend on
the resource, the "*" request is only useful as a "ping" or "no-op"
type of method; it does nothing beyond allowing the client to test
the capabilities of the server. For example, this can be used to test
a proxy for HTTP/1.1 compliance (or lack thereof).
</t>
<t>
If the request-target is not an asterisk, the OPTIONS request applies
only to the options that are available when communicating with that
resource.
</t>
<t>
A 200 response SHOULD include any header fields that indicate
optional features implemented by the server and applicable to that
resource (e.g., Allow), possibly including extensions not defined by
this specification. The response body, if any, SHOULD also include
information about the communication options. The format for such a
body is not defined by this specification, but might be defined by
future extensions to HTTP. Content negotiation MAY be used to select
the appropriate response format. If no response body is included, the
response MUST include a Content-Length field with a field-value of
"0".
</t>
<t>
The Max-Forwards request-header field MAY be used to target a
specific proxy in the request chain (see <xref target="header.max-forwards"/>).
If no Max-Forwards field is present in the request, then the forwarded
request MUST NOT include a Max-Forwards field.
</t>
</section>
<section title="GET" anchor="GET">
<iref primary="true" item="GET method"/>
<iref primary="true" item="Methods" subitem="GET"/>
<t>
The GET method means retrieve whatever information (in the form of a
representation) currently corresponds to the target resource.
</t>
<t>
If the target resource is a data-producing process, it is the
produced data which shall be returned as the representation in the response and not
the source text of the process, unless that text happens to be the output of
the process.
</t>
<t>
The semantics of the GET method change to a "conditional GET" if the
request message includes an If-Modified-Since, If-Unmodified-Since,
If-Match, If-None-Match, or If-Range header field. A conditional GET
method requests that the representation be transferred only under the
circumstances described by the conditional header field(s). The
conditional GET method is intended to reduce unnecessary network
usage by allowing cached representations to be refreshed without requiring
multiple requests or transferring data already held by the client.
</t>
<t>
The semantics of the GET method change to a "partial GET" if the
request message includes a Range header field. A partial GET requests
that only part of the representation be transferred, as described in Section 5.4 of <xref target="Part5"/>.
The partial GET method is intended to reduce unnecessary
network usage by allowing partially-retrieved representations to be
completed without transferring data already held by the client.
</t>
<t>
The response to a GET request is cacheable and MAY be used to satisfy
subsequent GET and HEAD requests (see <xref target="Part6"/>).
</t>
<t>
See <xref target="encoding.sensitive.information.in.uris"/> for security considerations when used for forms.
</t>
</section>
<section title="HEAD" anchor="HEAD">
<iref primary="true" item="HEAD method"/>
<iref primary="true" item="Methods" subitem="HEAD"/>
<t>
The HEAD method is identical to GET except that the server MUST NOT
return a message-body in the response. The metadata contained
in the HTTP headers in response to a HEAD request SHOULD be identical
to the information sent in response to a GET request. This method can
be used for obtaining metadata about the representation implied by the
request without transferring the representation body. This method is
often used for testing hypertext links for validity, accessibility,
and recent modification.
</t>
<t>
The response to a HEAD request is cacheable and MAY be used to satisfy
a subsequent HEAD request; see <xref target="Part6"/>. It also MAY be used to update a previously cached
representation from that resource; if the new field values
indicate that the cached representation differs from the current representation (as
would be indicated by a change in Content-Length, Content-MD5, ETag
or Last-Modified), then the cache MUST treat the cache entry as
stale.
</t>
</section>
<section title="POST" anchor="POST">
<iref primary="true" item="POST method"/>
<iref primary="true" item="Methods" subitem="POST"/>
<t>
The POST method is used to request that the origin server accept the
representation enclosed in the request as data to be processed by the
target resource. POST is designed to allow a uniform method to cover the
following functions:
<list style="symbols">
<t>
Annotation of existing resources;
</t>
<t>
Posting a message to a bulletin board, newsgroup, mailing list,
or similar group of articles;
</t>
<t>
Providing a block of data, such as the result of submitting a
form, to a data-handling process;
</t>
<t>
Extending a database through an append operation.
</t>
</list>
</t>
<t>
The actual function performed by the POST method is determined by the
server and is usually dependent on the effective request URI.
</t>
<t>
The action performed by the POST method might not result in a
resource that can be identified by a URI. In this case, either 200
(OK) or 204 (No Content) is the appropriate response status code,
depending on whether or not the response includes a representation that
describes the result.
</t>
<t>
If a resource has been created on the origin server, the response
SHOULD be 201 (Created) and contain a representation which describes the
status of the request and refers to the new resource, and a Location
header (see <xref target="header.location"/>).
</t>
<t>
Responses to POST requests are only cacheable when they
include explicit freshness information (see Section 2.3.1 of <xref target="Part6"/>). A
cached POST response with a Content-Location header
(see Section 6.7 of <xref target="Part3"/>) whose value is the effective
Request URI MAY be used to satisfy subsequent GET and HEAD requests.
</t>
<t>
Note that POST caching is not widely implemented.
However, the 303 (See Other) response can be used to direct the
user agent to retrieve a cacheable resource.
</t>
</section>
<section title="PUT" anchor="PUT">
<iref primary="true" item="PUT method"/>
<iref primary="true" item="Methods" subitem="PUT"/>
<t>
The PUT method requests that the enclosed representation be stored at the
effective request URI. If the effective request URI refers to an already
existing resource, the enclosed representation SHOULD be considered a
modified version of the one residing on the origin server. Otherwise, if the
effective request URI does not point to an existing resource, and that URI is
capable of being defined as a new resource by the requesting user
agent, the origin server can create the resource with that URI.
</t>
<t>
If a new resource is created at the effective request URI, the origin
server MUST inform the user agent
via the 201 (Created) response. If an existing resource is modified,
either the 200 (OK) or 204 (No Content) response codes SHOULD be sent
to indicate successful completion of the request.
</t>
<t>
If the target resource could not be created or modified, an appropriate
error response SHOULD be given that reflects the nature of the problem.
The recipient of the representation MUST NOT ignore any Content-*
headers (headers starting with the prefix "Content-") that it does
not understand or implement
and MUST return a 501 (Not Implemented) response in such cases.
</t>
<t>
If the request passes through a cache that has one or more stored
responses for the effective request URI, those stored responses
SHOULD be marked as stale if the response to the PUT request
has a success status code. Responses to the PUT method are
not cacheable.
</t>
<t>
The fundamental difference between the POST and PUT requests is
reflected in the different meaning of the effective request URI. The URI in a
POST request identifies the resource that will handle the enclosed
representation. That resource might be a data-accepting process, a gateway to
some other protocol, or a document that accepts annotations.
In contrast, the URI in a PUT request identifies the resource for
which enclosed representation is a new or replacement value; the
user agent knows what URI is intended and the server MUST NOT attempt
to apply the request to some other resource.
If the server desires that the request be applied to a different URI,
it MUST send a 301 (Moved Permanently) response; the user agent MAY
then make its own decision regarding whether or not to redirect the
request.
</t>
<t>
A single resource MAY be identified by many different URIs. For
example, an article might have a URI for identifying "the current
version" which is separate from the URI identifying each particular
version. In this case, a PUT request on a general URI might result in
several other URIs being defined by the origin server.
</t>
<t>
HTTP/1.1 does not define how a PUT method affects the state of an
origin server.
</t>
<t>
Header fields in a PUT request that are recognized as representation
metadata SHOULD be applied to the resource created or modified by
the PUT. Unrecognized header fields SHOULD be ignored.
</t>
</section>
<section title="DELETE" anchor="DELETE">
<iref primary="true" item="DELETE method"/>
<iref primary="true" item="Methods" subitem="DELETE"/>
<t>
The DELETE method requests that the origin server delete the target
resource. This method MAY be overridden by
human intervention (or other means) on the origin server. The client cannot
be guaranteed that the operation has been carried out, even if the
status code returned from the origin server indicates that the action
has been completed successfully. However, the server SHOULD NOT
indicate success unless, at the time the response is given, it
intends to delete the resource or move it to an inaccessible
location.
</t>
<t>
A successful response SHOULD be 200 (OK) if the response includes an
representation describing the status, 202 (Accepted) if the action has not
yet been enacted, or 204 (No Content) if the action has been enacted
but the response does not include a representation.
</t>
<t>
If the request passes through a cache and the effective request URI
identifies one or more currently cached representations, those entries SHOULD be
treated as stale. Responses to the DELETE method are not cacheable.
</t>
</section>
<section title="TRACE" anchor="TRACE">
<iref primary="true" item="TRACE method"/>
<iref primary="true" item="Methods" subitem="TRACE"/>
<t>
The TRACE method is used to invoke a remote, application-layer loop-back
of the request message. The final recipient of the request
SHOULD reflect the message received back to the client as the
message-body of a 200 (OK) response. The final recipient is either the
origin server or the first proxy or gateway to receive a Max-Forwards
value of zero (0) in the request (see <xref target="header.max-forwards"/>).
A TRACE request MUST NOT include a message-body.
</t>
<t>
TRACE allows the client to see what is being received at the other
end of the request chain and use that data for testing or diagnostic
information. The value of the Via header field (Section 9.9 of <xref target="Part1"/>) is of
particular interest, since it acts as a trace of the request chain.
Use of the Max-Forwards header field allows the client to limit the
length of the request chain, which is useful for testing a chain of
proxies forwarding messages in an infinite loop.
</t>
<t>
If the request is valid, the response SHOULD have a Content-Type of
"message/http" (see Section 10.3.1 of <xref target="Part1"/>) and contain a message-body
that encloses a copy of the entire request message.
Responses to the TRACE method are not cacheable.
</t>
</section>
<section title="CONNECT" anchor="CONNECT">
<iref primary="true" item="CONNECT method"/>
<iref primary="true" item="Methods" subitem="CONNECT"/>
<t>
This specification reserves the method name CONNECT for use with a
proxy that can dynamically switch to being a tunnel (e.g., SSL
tunneling <xref target="RFC2817"/>).
</t>
</section>
</section>
<section title="Status Code Definitions" anchor="status.codes">
<t>
Each Status-Code is described below, including any metadata required
in the response.
</t>
<section title="Informational 1xx" anchor="status.1xx">
<t>
This class of status code indicates a provisional response,
consisting only of the Status-Line and optional headers, and is
terminated by an empty line. There are no required headers for this
class of status code. Since HTTP/1.0 did not define any 1xx status
codes, servers MUST NOT send a 1xx response to an HTTP/1.0 client
except under experimental conditions.
</t>
<t>
A client MUST be prepared to accept one or more 1xx status responses
prior to a regular response, even if the client does not expect a 100
(Continue) status message. Unexpected 1xx status responses MAY be
ignored by a user agent.
</t>
<t>
Proxies MUST forward 1xx responses, unless the connection between the
proxy and its client has been closed, or unless the proxy itself
requested the generation of the 1xx response. (For example, if a
proxy adds a "Expect: 100-continue" field when it forwards a request,
then it need not forward the corresponding 100 (Continue)
response(s).)
</t>
<section title="100 Continue" anchor="status.100">
<iref primary="true" item="100 Continue (status code)"/>
<iref primary="true" item="Status Codes" subitem="100 Continue"/>
<t>
The client SHOULD continue with its request. This interim response is
used to inform the client that the initial part of the request has
been received and has not yet been rejected by the server. The client
SHOULD continue by sending the remainder of the request or, if the
request has already been completed, ignore this response. The server
MUST send a final response after the request has been completed. See
Section 7.2.3 of <xref target="Part1"/> for detailed discussion of the use and handling of this
status code.
</t>
</section>
<section title="101 Switching Protocols" anchor="status.101">
<iref primary="true" item="101 Switching Protocols (status code)"/>
<iref primary="true" item="Status Codes" subitem="101 Switching Protocols"/>
<t>
The server understands and is willing to comply with the client's
request, via the Upgrade message header field (Section 9.8 of <xref target="Part1"/>), for a
change in the application protocol being used on this connection. The
server will switch protocols to those defined by the response's
Upgrade header field immediately after the empty line which
terminates the 101 response.
</t>
<t>
The protocol SHOULD be switched only when it is advantageous to do
so. For example, switching to a newer version of HTTP is advantageous
over older versions, and switching to a real-time, synchronous
protocol might be advantageous when delivering resources that use
such features.
</t>
</section>
</section>
<section title="Successful 2xx" anchor="status.2xx">
<t>
This class of status code indicates that the client's request was
successfully received, understood, and accepted.
</t>
<section title="200 OK" anchor="status.200">
<iref primary="true" item="200 OK (status code)"/>
<iref primary="true" item="Status Codes" subitem="200 OK"/>
<t>
The request has succeeded. The payload returned with the response
is dependent on the method used in the request, for example:
<list style="hanging">
<t hangText="GET">
a representation of the target resource is sent in the response;
</t>
<t hangText="HEAD">
the same representation as GET, except without the message-body;
</t>
<t hangText="POST">
a representation describing or containing the result of the action;
</t>
<t hangText="TRACE">
a representation containing the request message as received by the
end server.
</t>
</list>
</t>
<t>
Caches MAY use a heuristic (see Section 2.3.1.1 of <xref target="Part6"/>) to determine
freshness for 200 responses.
</t>
</section>
<section title="201 Created" anchor="status.201">
<iref primary="true" item="201 Created (status code)"/>
<iref primary="true" item="Status Codes" subitem="201 Created"/>
<t>
The request has been fulfilled and has resulted in a new resource being
created. The newly created resource can be referenced by the URI(s)
returned in the payload of the response, with the most specific URI
for the resource given by a Location header field. The response
SHOULD include a payload containing a list of resource
characteristics and location(s) from which the user or user agent can
choose the one most appropriate. The payload format is specified by
the media type given in the Content-Type header field. The origin
server MUST create the resource before returning the 201 status code.
If the action cannot be carried out immediately, the server SHOULD
respond with 202 (Accepted) response instead.
</t>
<t>
A 201 response MAY contain an ETag response header field indicating
the current value of the entity-tag for the representation of the resource
just created (see Section 6.1 of <xref target="Part4"/>).
</t>
</section>
<section title="202 Accepted" anchor="status.202">
<iref primary="true" item="202 Accepted (status code)"/>
<iref primary="true" item="Status Codes" subitem="202 Accepted"/>
<t>
The request has been accepted for processing, but the processing has
not been completed. The request might or might not eventually be
acted upon, as it might be disallowed when processing actually takes
place. There is no facility for re-sending a status code from an
asynchronous operation such as this.
</t>
<t>
The 202 response is intentionally non-committal. Its purpose is to
allow a server to accept a request for some other process (perhaps a
batch-oriented process that is only run once per day) without
requiring that the user agent's connection to the server persist
until the process is completed. The representation returned with this
response SHOULD include an indication of the request's current status
and either a pointer to a status monitor or some estimate of when the
user can expect the request to be fulfilled.
</t>
</section>
<section title="203 Non-Authoritative Information" anchor="status.203">
<iref primary="true" item="203 Non-Authoritative Information (status code)"/>
<iref primary="true" item="Status Codes" subitem="203 Non-Authoritative Information"/>
<t>
The returned metadata in the header fields is not the
definitive set as available from the origin server, but is gathered
from a local or a third-party copy. The set presented MAY be a subset
or superset of the original version. For example, including local
annotation information about the resource might result in a superset
of the metadata known by the origin server. Use of this
response code is not required and is only appropriate when the
response would otherwise be 200 (OK).
</t>
<t>
Caches MAY use a heuristic (see Section 2.3.1.1 of <xref target="Part6"/>) to determine
freshness for 203 responses.
</t>
</section>
<section title="204 No Content" anchor="status.204">
<iref primary="true" item="204 No Content (status code)"/>
<iref primary="true" item="Status Codes" subitem="204 No Content"/>
<t>
The server has successfully fulfilled the request, but there is no
additional content to return in the response payload body. The
resource metadata and representation metadata in the response message's
header fields refer to the target resource
and its current representation, respectively, after the requested action.
For example, if a 204 status code is received in response to a PUT
and the response contains an ETag header field, then the value of
that field is the current entity-tag for the representation that
was successfully PUT.
</t>
<t>
If the client is a user agent, it SHOULD NOT change its document view
from that which caused the request to be sent. This response is
primarily intended to allow input for actions to take place without
causing a change to the user agent's active document view, although
any new or updated metadata SHOULD be applied to the document
currently in the user agent's active view.
</t>
<t>
The 204 response MUST NOT include a message-body, and thus is always
terminated by the first empty line after the header fields.
</t>
</section>
<section title="205 Reset Content" anchor="status.205">
<iref primary="true" item="205 Reset Content (status code)"/>
<iref primary="true" item="Status Codes" subitem="205 Reset Content"/>
<t>
The server has fulfilled the request and the user agent SHOULD reset
the document view which caused the request to be sent. This response
is primarily intended to allow input for actions to take place via
user input, followed by a clearing of the form in which the input is
given so that the user can easily initiate another input action. The
response MUST NOT include a message-body.
</t>
</section>
<section title="206 Partial Content" anchor="status.206">
<iref primary="true" item="206 Partial Content (status code)"/>
<iref primary="true" item="Status Codes" subitem="206 Partial Content"/>
<t>
The server has fulfilled the partial GET request for the resource
and the enclosed payload is a partial representation as defined in Section 3.1 of <xref target="Part5"/>.
</t>
<t>
Caches MAY use a heuristic (see Section 2.3.1.1 of <xref target="Part6"/>) to determine
freshness for 206 responses.
</t>
</section>
</section>
<section title="Redirection 3xx" anchor="status.3xx">
<t>
This class of status code indicates that further action needs to be
taken by the user agent in order to fulfill the request. The action
required MAY be carried out by the user agent without interaction
with the user if and only if the method used in the second request is
known to be "safe", as defined in <xref target="safe.methods"/>.
A client SHOULD detect infinite redirection loops, since such loops
generate network traffic for each redirection.
</t>
<t><list>
<t>
Note: An earlier version of this specification recommended a
maximum of five redirections (<xref target="RFC2068"/>, Section 10.3).
Content developers need to be aware that some clients might
implement such a fixed limitation.
</t>
</list></t>
<section title="300 Multiple Choices" anchor="status.300">
<iref primary="true" item="300 Multiple Choices (status code)"/>
<iref primary="true" item="Status Codes" subitem="300 Multiple Choices"/>
<t>
The target resource more than one
representation, each with its own specific location, and agent-driven
negotiation information (Section 5 of <xref target="Part3"/>) is being provided so that
the user (or user agent) can select a preferred representation by
redirecting its request to that location.
</t>
<t>
Unless it was a HEAD request, the response SHOULD include a representation
containing a list of representation metadata and location(s) from
which the user or user agent can choose the one most appropriate. The
data format is specified by the media type given in the Content-Type
header field. Depending upon the format and the capabilities of
the user agent, selection of the most appropriate choice MAY be
performed automatically. However, this specification does not define
any standard for such automatic selection.
</t>
<t>
If the server has a preferred choice of representation, it SHOULD
include the specific URI for that representation in the Location
field; user agents MAY use the Location field value for automatic
redirection.
</t>
<t>
Caches MAY use a heuristic (see Section 2.3.1.1 of <xref target="Part6"/>) to determine
freshness for 300 responses.
</t>
</section>
<section title="301 Moved Permanently" anchor="status.301">
<iref primary="true" item="301 Moved Permanently (status code)"/>
<iref primary="true" item="Status Codes" subitem="301 Moved Permanently"/>
<t>
The target resource has been assigned a new permanent URI and any
future references to this resource SHOULD use one of the returned
URIs. Clients with link editing capabilities ought to automatically
re-link references to the effective request URI to one or more of the new
references returned by the server, where possible.
</t>
<t>
Caches MAY use a heuristic (see Section 2.3.1.1 of <xref target="Part6"/>) to determine
freshness for 301 responses.
</t>
<t>
The new permanent URI SHOULD be given by the Location field in the
response. Unless the request method was HEAD, the representation of the
response SHOULD contain a short hypertext note with a hyperlink to
the new URI(s).
</t>
<t>
If the 301 status code is received in response to a request method
that is known to be "safe", as defined in <xref target="safe.methods"/>,
then the request MAY be automatically redirected by the user agent without
confirmation. Otherwise, the user agent MUST NOT automatically redirect the
request unless it can be confirmed by the user, since this might
change the conditions under which the request was issued.
</t>
<t><list>
<t>
Note: When automatically redirecting a POST request after
receiving a 301 status code, some existing HTTP/1.0 user agents
will erroneously change it into a GET request.
</t>
</list></t>
</section>
<section title="302 Found" anchor="status.302">
<iref primary="true" item="302 Found (status code)"/>
<iref primary="true" item="Status Codes" subitem="302 Found"/>
<t>
The target resource resides temporarily under a different URI.
Since the redirection might be altered on occasion, the client SHOULD
continue to use the effective request URI for future requests.
</t>
<t>
The temporary URI SHOULD be given by the Location field in the
response. Unless the request method was HEAD, the representation of the
response SHOULD contain a short hypertext note with a hyperlink to
the new URI(s).
</t>
<t>
If the 302 status code is received in response to a request method
that is known to be "safe", as defined in <xref target="safe.methods"/>,
then the request MAY be automatically redirected by the user agent without
confirmation. Otherwise, the user agent MUST NOT automatically redirect the
request unless it can be confirmed by the user, since this might
change the conditions under which the request was issued.
</t>
<t><list>
<t>
Note: HTTP/1.0 (<xref target="RFC1945"/>, Section 9.3)
and the first version of HTTP/1.1 (<xref target="RFC2068"/>, Section 10.3.3)
specify that the client is not allowed to change the method on the
redirected request. However, most existing user agent implementations
treat 302 as if it were a 303 response, performing a GET on the Location
field-value regardless of the original request method. Therefore, a
previous version of this specification
(<xref target="RFC2616"/>, Section 10.3.3) has added the
status codes
<xref target="status.303" format="none">303</xref> and
<xref target="status.307" format="none">307</xref> for servers that wish
to make unambiguously clear which kind of reaction is expected of the
client.
</t>
</list></t>
</section>
<section title="303 See Other" anchor="status.303">
<iref primary="true" item="303 See Other (status code)"/>
<iref primary="true" item="Status Codes" subitem="303 See Other"/>
<t>
The server directs the user agent to a different resource, indicated
by a URI in the Location header field, that provides an indirect
response to the original request. The user agent MAY perform a GET
request on the URI in the Location field in order to obtain a
representation corresponding to the response, be redirected again,
or end with an error status. The Location URI is not a substitute
reference for the effective request URI.
</t>
<t>
The 303 status code is generally applicable to any HTTP method. It is
primarily used to allow the output of a POST action to redirect
the user agent to a selected resource, since doing so provides the
information corresponding to the POST response in a form that
can be separately identified, bookmarked, and cached independent
of the original request.
</t>
<t>
A 303 response to a GET request indicates that the requested
resource does not have a representation of its own that can be
transferred by the server over HTTP. The Location URI indicates a
resource that is descriptive of the target resource, such that the
follow-on representation might be useful to recipients without
implying that it adequately represents the target resource.
Note that answers to the questions of what can be represented, what
representations are adequate, and what might be a useful description
are outside the scope of HTTP and thus entirely determined by the
URI owner(s).
</t>
<t>
Except for responses to a HEAD request, the representation of a 303
response SHOULD contain a short hypertext note with a hyperlink
to the Location URI.
</t>
</section>
<section title="304 Not Modified" anchor="status.304">
<iref primary="true" item="304 Not Modified (status code)"/>
<iref primary="true" item="Status Codes" subitem="304 Not Modified"/>
<t>
The response to the request has not been modified since the conditions
indicated by the client's conditional GET request, as defined in Section 3.1 of <xref target="Part4"/>.
</t>
</section>
<section title="305 Use Proxy" anchor="status.305">
<iref primary="true" item="305 Use Proxy (status code)"/>
<iref primary="true" item="Status Codes" subitem="305 Use Proxy"/>
<t>
The 305 status code was defined in a previous version of this specification
(see <xref target="changes.from.rfc.2616"/>), and is now deprecated.
</t>
</section>
<section title="306 (Unused)" anchor="status.306">
<iref primary="true" item="306 (Unused) (status code)"/>
<iref primary="true" item="Status Codes" subitem="306 (Unused)"/>
<t>
The 306 status code was used in a previous version of the
specification, is no longer used, and the code is reserved.
</t>
</section>
<section title="307 Temporary Redirect" anchor="status.307">
<iref primary="true" item="307 Temporary Redirect (status code)"/>
<iref primary="true" item="Status Codes" subitem="307 Temporary Redirect"/>
<t>
The target resource resides temporarily under a different URI.
Since the redirection can change over time, the client SHOULD
continue to use the effective request URI for future requests.
</t>
<t>
The temporary URI SHOULD be given by the Location field in the
response. Unless the request method was HEAD, the representation of the
response SHOULD contain a short hypertext note with a hyperlink to
the new URI(s) , since many pre-HTTP/1.1 user agents do not
understand the 307 status code. Therefore, the note SHOULD contain the
information necessary for a user to repeat the original request on
the new URI.
</t>
<t>
If the 307 status code is received in response to a request method
that is known to be "safe", as defined in <xref target="safe.methods"/>,
then the request MAY be automatically redirected by the user agent without
confirmation. Otherwise, the user agent MUST NOT automatically redirect the
request unless it can be confirmed by the user, since this might
change the conditions under which the request was issued.
</t>
</section>
</section>
<section title="Client Error 4xx" anchor="status.4xx">
<t>
The 4xx class of status code is intended for cases in which the
client seems to have erred. Except when responding to a HEAD request,
the server SHOULD include a representation containing an explanation of the
error situation, and whether it is a temporary or permanent
condition. These status codes are applicable to any request method.
User agents SHOULD display any included representation to the user.
</t>
<t>
If the client is sending data, a server implementation using TCP
SHOULD be careful to ensure that the client acknowledges receipt of
the packet(s) containing the response, before the server closes the
input connection. If the client continues sending data to the server
after the close, the server's TCP stack will send a reset packet to
the client, which might erase the client's unacknowledged input buffers
before they can be read and interpreted by the HTTP application.
</t>
<section title="400 Bad Request" anchor="status.400">
<iref primary="true" item="400 Bad Request (status code)"/>
<iref primary="true" item="Status Codes" subitem="400 Bad Request"/>
<t>
The request could not be understood by the server due to malformed
syntax. The client SHOULD NOT repeat the request without
modifications.
</t>
</section>
<section title="401 Unauthorized" anchor="status.401">
<iref primary="true" item="401 Unauthorized (status code)"/>
<iref primary="true" item="Status Codes" subitem="401 Unauthorized"/>
<t>
The request requires user authentication (see Section 2.1 of <xref target="Part7"/>).
</t>
</section>
<section title="402 Payment Required" anchor="status.402">
<iref primary="true" item="402 Payment Required (status code)"/>
<iref primary="true" item="Status Codes" subitem="402 Payment Required"/>
<t>
This code is reserved for future use.
</t>
</section>
<section title="403 Forbidden" anchor="status.403">
<iref primary="true" item="403 Forbidden (status code)"/>
<iref primary="true" item="Status Codes" subitem="403 Forbidden"/>
<t>
The server understood the request, but is refusing to fulfill it.
Authorization will not help and the request SHOULD NOT be repeated.
If the request method was not HEAD and the server wishes to make
public why the request has not been fulfilled, it SHOULD describe the
reason for the refusal in the representation. If the server does not wish to
make this information available to the client, the status code 404
(Not Found) can be used instead.
</t>
</section>
<section title="404 Not Found" anchor="status.404">
<iref primary="true" item="404 Not Found (status code)"/>
<iref primary="true" item="Status Codes" subitem="404 Not Found"/>
<t>
The server has not found anything matching the effective request URI. No
indication is given of whether the condition is temporary or
permanent. The 410 (Gone) status code SHOULD be used if the server
knows, through some internally configurable mechanism, that an old
resource is permanently unavailable and has no forwarding address.
This status code is commonly used when the server does not wish to
reveal exactly why the request has been refused, or when no other
response is applicable.
</t>
</section>
<section title="405 Method Not Allowed" anchor="status.405">
<iref primary="true" item="405 Method Not Allowed (status code)"/>
<iref primary="true" item="Status Codes" subitem="405 Method Not Allowed"/>
<t>
The method specified in the Request-Line is not allowed for the target
resource. The response MUST include an
Allow header containing a list of valid methods for the requested
resource.
</t>
</section>
<section title="406 Not Acceptable" anchor="status.406">
<iref primary="true" item="406 Not Acceptable (status code)"/>
<iref primary="true" item="Status Codes" subitem="406 Not Acceptable"/>
<t>
The resource identified by the request is only capable of generating
response representations which have content characteristics not acceptable
according to the accept headers sent in the request.
</t>
<t>
Unless it was a HEAD request, the response SHOULD include a representation
containing a list of available representation characteristics and location(s)
from which the user or user agent can choose the one most
appropriate. The data format is specified by the media type given
in the Content-Type header field. Depending upon the format and the
capabilities of the user agent, selection of the most appropriate
choice MAY be performed automatically. However, this specification
does not define any standard for such automatic selection.
</t>
<t><list>
<t>
Note: HTTP/1.1 servers are allowed to return responses which are
not acceptable according to the accept headers sent in the
request. In some cases, this might even be preferable to sending a
406 response. User agents are encouraged to inspect the headers of
an incoming response to determine if it is acceptable.
</t>
</list></t>
<t>
If the response could be unacceptable, a user agent SHOULD
temporarily stop receipt of more data and query the user for a
decision on further actions.
</t>
</section>
<section title="407 Proxy Authentication Required" anchor="status.407">
<iref primary="true" item="407 Proxy Authentication Required (status code)"/>
<iref primary="true" item="Status Codes" subitem="407 Proxy Authentication Required"/>
<t>
This code is similar to 401 (Unauthorized), but indicates that the
client must first authenticate itself with the proxy (see Section 2.2 of <xref target="Part7"/>).
</t>
</section>
<section title="408 Request Timeout" anchor="status.408">
<iref primary="true" item="408 Request Timeout (status code)"/>
<iref primary="true" item="Status Codes" subitem="408 Request Timeout"/>
<t>
The client did not produce a request within the time that the server
was prepared to wait. The client MAY repeat the request without
modifications at any later time.
</t>
</section>
<section title="409 Conflict" anchor="status.409">
<iref primary="true" item="409 Conflict (status code)"/>
<iref primary="true" item="Status Codes" subitem="409 Conflict"/>
<t>
The request could not be completed due to a conflict with the current
state of the resource. This code is only allowed in situations where
it is expected that the user might be able to resolve the conflict
and resubmit the request. The response body SHOULD include enough
information for the user to recognize the source of the conflict.
Ideally, the response representation would include enough information for the
user or user agent to fix the problem; however, that might not be
possible and is not required.
</t>
<t>
Conflicts are most likely to occur in response to a PUT request. For
example, if versioning were being used and the representation being PUT
included changes to a resource which conflict with those made by an
earlier (third-party) request, the server might use the 409 response
to indicate that it can't complete the request. In this case, the
response representation would likely contain a list of the differences
between the two versions in a format defined by the response
Content-Type.
</t>
</section>
<section title="410 Gone" anchor="status.410">
<iref primary="true" item="410 Gone (status code)"/>
<iref primary="true" item="Status Codes" subitem="410 Gone"/>
<t>
The target resource is no longer available at the server and no
forwarding address is known. This condition is expected to be
considered permanent. Clients with link editing capabilities SHOULD
delete references to the effective request URI after user approval. If the
server does not know, or has no facility to determine, whether or not
the condition is permanent, the status code 404 (Not Found) SHOULD be
used instead.
</t>
<t>
The 410 response is primarily intended to assist the task of web
maintenance by notifying the recipient that the resource is
intentionally unavailable and that the server owners desire that
remote links to that resource be removed. Such an event is common for
limited-time, promotional services and for resources belonging to
individuals no longer working at the server's site. It is not
necessary to mark all permanently unavailable resources as "gone" or
to keep the mark for any length of time -- that is left to the
discretion of the server owner.
</t>
<t>
Caches MAY use a heuristic (see Section 2.3.1.1 of <xref target="Part6"/>) to determine freshness
for 410 responses.
</t>
</section>
<section title="411 Length Required" anchor="status.411">
<iref primary="true" item="411 Length Required (status code)"/>
<iref primary="true" item="Status Codes" subitem="411 Length Required"/>
<t>
The server refuses to accept the request without a defined Content-Length.
The client MAY repeat the request if it adds a valid
Content-Length header field containing the length of the message-body
in the request message.
</t>
</section>
<section title="412 Precondition Failed" anchor="status.412">
<iref primary="true" item="412 Precondition Failed (status code)"/>
<iref primary="true" item="Status Codes" subitem="412 Precondition Failed"/>
<t>
The precondition given in one or more of the request-header fields
evaluated to false when it was tested on the server, as defined in
Section 3.2 of <xref target="Part4"/>.
</t>
</section>
<section title="413 Request Entity Too Large" anchor="status.413">
<iref primary="true" item="413 Request Entity Too Large (status code)"/>
<iref primary="true" item="Status Codes" subitem="413 Request Entity Too Large"/>
<t>
The server is refusing to process a request because the request
representation is larger than the server is willing or able to process. The
server MAY close the connection to prevent the client from continuing
the request.
</t>
<t>
If the condition is temporary, the server SHOULD include a Retry-After
header field to indicate that it is temporary and after what
time the client MAY try again.
</t>
</section>
<section title="414 URI Too Long" anchor="status.414">
<iref primary="true" item="414 URI Too Long (status code)"/>
<iref primary="true" item="Status Codes" subitem="414 URI Too Long"/>
<t>
The server is refusing to service the request because the effective request URI
is longer than the server is willing to interpret. This rare
condition is only likely to occur when a client has improperly
converted a POST request to a GET request with long query
information, when the client has descended into a URI "black hole" of
redirection (e.g., a redirected URI prefix that points to a suffix of
itself), or when the server is under attack by a client attempting to
exploit security holes present in some servers using fixed-length
buffers for reading or manipulating the effective request URI.
</t>
</section>
<section title="415 Unsupported Media Type" anchor="status.415">
<iref primary="true" item="415 Unsupported Media Type (status code)"/>
<iref primary="true" item="Status Codes" subitem="415 Unsupported Media Type"/>
<t>
The server is refusing to service the request because the representation of
the request is in a format not supported by the target resource
for the requested method.
</t>
</section>
<section title="416 Requested Range Not Satisfiable" anchor="status.416">
<iref primary="true" item="416 Requested Range Not Satisfiable (status code)"/>
<iref primary="true" item="Status Codes" subitem="416 Requested Range Not Satisfiable"/>
<t>
The request included a Range request-header field (Section 5.4 of <xref target="Part5"/>) and none of
the range-specifier values in this field overlap the current extent
of the selected resource. See Section 3.2 of <xref target="Part5"/>.
</t>
</section>
<section title="417 Expectation Failed" anchor="status.417">
<iref primary="true" item="417 Expectation Failed (status code)"/>
<iref primary="true" item="Status Codes" subitem="417 Expectation Failed"/>
<t>
The expectation given in an Expect request-header field (see <xref target="header.expect"/>)
could not be met by this server, or, if the server is a proxy,
the server has unambiguous evidence that the request could not be met
by the next-hop server.
</t>
</section>
</section>
<section title="Server Error 5xx" anchor="status.5xx">
<t>
Response status codes beginning with the digit "5" indicate cases in
which the server is aware that it has erred or is incapable of
performing the request. Except when responding to a HEAD request, the
server SHOULD include a representation containing an explanation of the
error situation, and whether it is a temporary or permanent
condition. User agents SHOULD display any included representation to the
user. These response codes are applicable to any request method.
</t>
<section title="500 Internal Server Error" anchor="status.500">
<iref primary="true" item="500 Internal Server Error (status code)"/>
<iref primary="true" item="Status Codes" subitem="500 Internal Server Error"/>
<t>
The server encountered an unexpected condition which prevented it
from fulfilling the request.
</t>
</section>
<section title="501 Not Implemented" anchor="status.501">
<iref primary="true" item="501 Not Implemented (status code)"/>
<iref primary="true" item="Status Codes" subitem="501 Not Implemented"/>
<t>
The server does not support the functionality required to fulfill the
request. This is the appropriate response when the server does not
recognize the request method and is not capable of supporting it for
any resource.
</t>
</section>
<section title="502 Bad Gateway" anchor="status.502">
<iref primary="true" item="502 Bad Gateway (status code)"/>
<iref primary="true" item="Status Codes" subitem="502 Bad Gateway"/>
<t>
The server, while acting as a gateway or proxy, received an invalid
response from the upstream server it accessed in attempting to
fulfill the request.
</t>
</section>
<section title="503 Service Unavailable" anchor="status.503">
<iref primary="true" item="503 Service Unavailable (status code)"/>
<iref primary="true" item="Status Codes" subitem="503 Service Unavailable"/>
<t>
The server is currently unable to handle the request due to a
temporary overloading or maintenance of the server. The implication
is that this is a temporary condition which will be alleviated after
some delay. If known, the length of the delay MAY be indicated in a
Retry-After header. If no Retry-After is given, the client SHOULD
handle the response as it would for a 500 response.
</t>
<t><list>
<t>
Note: The existence of the 503 status code does not imply that a
server must use it when becoming overloaded. Some servers might wish
to simply refuse the connection.
</t>
</list></t>
</section>
<section title="504 Gateway Timeout" anchor="status.504">
<iref primary="true" item="504 Gateway Timeout (status code)"/>
<iref primary="true" item="Status Codes" subitem="504 Gateway Timeout"/>
<t>
The server, while acting as a gateway or proxy, did not receive a
timely response from the upstream server specified by the URI (e.g.,
HTTP, FTP, LDAP) or some other auxiliary server (e.g., DNS) it needed
to access in attempting to complete the request.
</t>
<t><list>
<t>
Note to implementors: some deployed proxies are known to
return 400 or 500 when DNS lookups time out.
</t>
</list></t>
</section>
<section title="505 HTTP Version Not Supported" anchor="status.505">
<iref primary="true" item="505 HTTP Version Not Supported (status code)"/>
<iref primary="true" item="Status Codes" subitem="505 HTTP Version Not Supported"/>
<t>
The server does not support, or refuses to support, the protocol
version that was used in the request message. The server is
indicating that it is unable or unwilling to complete the request
using the same major version as the client, as described in Section 2.5 of <xref target="Part1"/>,
other than with this error message. The response SHOULD contain
a representation describing why that version is not supported and what other
protocols are supported by that server.
</t>
</section>
</section>
</section>
<section title="Header Field Definitions" anchor="header.fields">
<t>
This section defines the syntax and semantics of HTTP/1.1 header fields
related to request and response semantics.
</t>
<section title="Allow" anchor="header.allow">
<iref primary="true" item="Allow header"/>
<iref primary="true" item="Headers" subitem="Allow"/>
<t>
The "Allow" response-header field lists the set of methods advertised as
supported by the target resource. The purpose of
this field is strictly to inform the recipient of valid methods
associated with the resource.
</t>
<figure><iref primary="true" item="Grammar" subitem="Allow"/><iref primary="true" item="Grammar" subitem="Allow-v"/><artwork type="abnf2616"><![CDATA[
Allow = "Allow" ":" OWS Allow-v
Allow-v = #Method
]]></artwork></figure>
<t>
Example of use:
</t>
<figure><artwork type="example"><![CDATA[
Allow: GET, HEAD, PUT
]]></artwork></figure>
<t>
The actual set of allowed methods is defined
by the origin server at the time of each request.
</t>
<t>
A proxy MUST NOT modify the Allow header field even if it does not
understand all the methods specified, since the user agent might
have other means of communicating with the origin server.
</t>
</section>
<section title="Expect" anchor="header.expect">
<iref primary="true" item="Expect header"/>
<iref primary="true" item="Headers" subitem="Expect"/>
<t>
The "Expect" request-header field is used to indicate that particular
server behaviors are required by the client.
</t>
<figure><iref primary="true" item="Grammar" subitem="Expect"/><iref primary="true" item="Grammar" subitem="Expect-v"/><iref primary="true" item="Grammar" subitem="expectation"/><iref primary="true" item="Grammar" subitem="expectation-extension"/><iref primary="true" item="Grammar" subitem="expect-params"/><artwork type="abnf2616"><![CDATA[
Expect = "Expect" ":" OWS Expect-v
Expect-v = 1#expectation
expectation = "100-continue" / expectation-extension
expectation-extension = token [ "=" ( token / quoted-string )
*expect-params ]
expect-params = ";" token [ "=" ( token / quoted-string ) ]
]]></artwork></figure>
<t>
A server that does not understand or is unable to comply with any of
the expectation values in the Expect field of a request MUST respond
with appropriate error status code. The server MUST respond with a 417
(Expectation Failed) status code if any of the expectations cannot be met
or, if there are other problems with the request, some other 4xx
status code.
</t>
<t>
This header field is defined with extensible syntax to allow for
future extensions. If a server receives a request containing an
Expect field that includes an expectation-extension that it does not
support, it MUST respond with a 417 (Expectation Failed) status code.
</t>
<t>
Comparison of expectation values is case-insensitive for unquoted
tokens (including the 100-continue token), and is case-sensitive for
quoted-string expectation-extensions.
</t>
<t>
The Expect mechanism is hop-by-hop: that is, an HTTP/1.1 proxy MUST
return a 417 (Expectation Failed) status code if it receives a request
with an expectation that it cannot meet. However, the Expect
request-header itself is end-to-end; it MUST be forwarded if the
request is forwarded.
</t>
<t>
Many older HTTP/1.0 and HTTP/1.1 applications do not understand the
Expect header.
</t>
<t>
See Section 7.2.3 of <xref target="Part1"/> for the use of the 100 (Continue) status code.
</t>
</section>
<section title="From" anchor="header.from">
<iref primary="true" item="From header"/>
<iref primary="true" item="Headers" subitem="From"/>
<t>
The "From" request-header field, if given, SHOULD contain an Internet
e-mail address for the human user who controls the requesting user
agent. The address SHOULD be machine-usable, as defined by "mailbox"
in Section 3.4 of <xref target="RFC5322"/>:
</t>
<figure><iref primary="true" item="Grammar" subitem="From"/><iref primary="true" item="Grammar" subitem="From-v"/><artwork type="abnf2616"><![CDATA[
From = "From" ":" OWS From-v
From-v = mailbox
mailbox = <mailbox, defined in [RFC5322], Section 3.4>
]]></artwork></figure>
<t>
An example is:
</t>
<figure><artwork type="example"><![CDATA[
From: webmaster@example.org
]]></artwork></figure>
<t>
This header field MAY be used for logging purposes and as a means for
identifying the source of invalid or unwanted requests. It SHOULD NOT
be used as an insecure form of access protection. The interpretation
of this field is that the request is being performed on behalf of the
person given, who accepts responsibility for the method performed. In
particular, robot agents SHOULD include this header so that the
person responsible for running the robot can be contacted if problems
occur on the receiving end.
</t>
<t>
The Internet e-mail address in this field MAY be separate from the
Internet host which issued the request. For example, when a request
is passed through a proxy the original issuer's address SHOULD be
used.
</t>
<t>
The client SHOULD NOT send the From header field without the user's
approval, as it might conflict with the user's privacy interests or
their site's security policy. It is strongly recommended that the
user be able to disable, enable, and modify the value of this field
at any time prior to a request.
</t>
</section>
<section title="Location" anchor="header.location">
<iref primary="true" item="Location header"/>
<iref primary="true" item="Headers" subitem="Location"/>
<t>
The "Location" response-header field is used to identify a newly created
resource, or to redirect the recipient to a different location for
completion of the request.
</t>
<t>
For 201 (Created) responses, the Location is the URI of the new resource
which was created by the request. For 3xx responses, the location SHOULD
indicate the server's preferred URI for automatic redirection to the
resource.
</t>
<t>
The field value consists of a single URI-reference. When it has the form
of a relative reference (<xref target="RFC3986"/>, Section 4.2),
the final value is computed by resolving it against the effective request
URI (<xref target="RFC3986"/>, Section 5).
</t>
<figure><iref primary="true" item="Grammar" subitem="Location"/><iref primary="true" item="Grammar" subitem="Location-v"/><artwork type="abnf2616"><![CDATA[
Location = "Location" ":" OWS Location-v
Location-v = URI-reference
]]></artwork></figure>
<figure>
<preamble>Examples are:</preamble><!--DO NOT DARE changing the vertical WSP below, it's necessary this way for xml2rfc-->
<artwork type="example"><![CDATA[
Location: http://www.example.org/pub/WWW/People.html#tim
]]></artwork></figure><figure><artwork type="example"><![CDATA[ Location: /index.html
]]></artwork></figure>
<t>
There are circumstances in which a fragment identifier in a Location URI
would not be appropriate:
<list style="symbols">
<t>With a 201 Created response, because in this usage the Location header
specifies the URI for the entire created resource.</t>
<t>With 305 Use Proxy.</t>
</list>
</t>
<t><list>
<t>
Note: This specification does not define precedence rules
for the case where the original URI, as navigated to by the user
agent, and the Location header field value both contain fragment
identifiers.
</t>
</list></t>
<t><list>
<t>
Note: The Content-Location header field (Section 6.7 of <xref target="Part3"/>) differs
from Location in that the Content-Location identifies the most specific
resource corresponding to the enclosed representation.
It is therefore possible for a response to contain header fields for
both Location and Content-Location.
</t>
</list></t>
</section>
<section title="Max-Forwards" anchor="header.max-forwards">
<iref primary="true" item="Max-Forwards header"/>
<iref primary="true" item="Headers" subitem="Max-Forwards"/>
<t>
The "Max-Forwards" request-header field provides a mechanism with the
TRACE (<xref target="TRACE"/>) and OPTIONS (<xref target="OPTIONS"/>)
methods to limit the number of times that the request is forwarded by
proxies or gateways. This can be useful when the client is attempting to
trace a request which appears to be failing or looping in mid-chain.
</t>
<figure><iref primary="true" item="Grammar" subitem="Max-Forwards"/><iref primary="true" item="Grammar" subitem="Max-Forwards-v"/><artwork type="abnf2616"><![CDATA[
Max-Forwards = "Max-Forwards" ":" OWS Max-Forwards-v
Max-Forwards-v = 1*DIGIT
]]></artwork></figure>
<t>
The Max-Forwards value is a decimal integer indicating the remaining
number of times this request message can be forwarded.
</t>
<t>
Each proxy or gateway recipient of a TRACE or OPTIONS request
containing a Max-Forwards header field MUST check and update its
value prior to forwarding the request. If the received value is zero
(0), the recipient MUST NOT forward the request; instead, it MUST
respond as the final recipient. If the received Max-Forwards value is
greater than zero, then the forwarded message MUST contain an updated
Max-Forwards field with a value decremented by one (1).
</t>
<t>
The Max-Forwards header field MAY be ignored for all other methods
defined by this specification and for any extension methods for which
it is not explicitly referred to as part of that method definition.
</t>
</section>
<section title="Referer" anchor="header.referer">
<iref primary="true" item="Referer header"/>
<iref primary="true" item="Headers" subitem="Referer"/>
<t>
The "Referer" [sic] request-header field allows the client to specify the
URI of the resource from which the effective request URI was obtained (the
"referrer", although the header field is misspelled.).
</t>
<t>
The Referer header allows servers to generate lists of back-links to
resources for interest, logging, optimized caching, etc. It also allows
obsolete or mistyped links to be traced for maintenance. Some servers use
Referer as a means of controlling where they allow links from (so-called
"deep linking"), but legitimate requests do not always
contain a Referer header field.
</t>
<t>
If the effective request URI was obtained from a source that does not have its own
URI (e.g., input from the user keyboard), the Referer field MUST either be
sent with the value "about:blank", or not be sent at all. Note that this
requirement does not apply to sources with non-HTTP URIs (e.g., FTP).
</t>
<figure><iref primary="true" item="Grammar" subitem="Referer"/><iref primary="true" item="Grammar" subitem="Referer-v"/><artwork type="abnf2616"><![CDATA[
Referer = "Referer" ":" OWS Referer-v
Referer-v = absolute-URI / partial-URI
]]></artwork></figure>
<t>
Example:
</t>
<figure><artwork type="example"><![CDATA[
Referer: http://www.example.org/hypertext/Overview.html
]]></artwork></figure>
<t>
If the field value is a relative URI, it SHOULD be interpreted
relative to the effective request URI. The URI MUST NOT include a fragment. See
<xref target="encoding.sensitive.information.in.uris"/> for security considerations.
</t>
</section>
<section title="Retry-After" anchor="header.retry-after">
<iref primary="true" item="Retry-After header"/>
<iref primary="true" item="Headers" subitem="Retry-After"/>
<t>
The response-header "Retry-After" field can be used with a 503 (Service
Unavailable) response to indicate how long the service is expected to
be unavailable to the requesting client. This field MAY also be used
with any 3xx (Redirection) response to indicate the minimum time the
user-agent is asked wait before issuing the redirected request.
</t>
<t>
The value of this field can be either an HTTP-date or an integer number
of seconds (in decimal) after the time of the response.
</t>
<figure><iref primary="true" item="Grammar" subitem="Retry-After"/><iref primary="true" item="Grammar" subitem="Retry-After-v"/><artwork type="abnf2616"><![CDATA[
Retry-After = "Retry-After" ":" OWS Retry-After-v
Retry-After-v = HTTP-date / delta-seconds
]]></artwork></figure>
<t anchor="rule.delta-seconds">
Time spans are non-negative decimal integers, representing time in
seconds.
</t>
<figure><iref primary="true" item="Grammar" subitem="delta-seconds"/><artwork type="abnf2616"><![CDATA[
delta-seconds = 1*DIGIT
]]></artwork></figure>
<t>
Two examples of its use are
</t>
<figure><artwork type="example"><![CDATA[
Retry-After: Fri, 31 Dec 1999 23:59:59 GMT
Retry-After: 120
]]></artwork></figure>
<t>
In the latter example, the delay is 2 minutes.
</t>
</section>
<section title="Server" anchor="header.server">
<iref primary="true" item="Server header"/>
<iref primary="true" item="Headers" subitem="Server"/>
<t>
The "Server" response-header field contains information about the
software used by the origin server to handle the request.
</t>
<t>
The field can contain multiple product tokens (Section 6.3 of <xref target="Part1"/>) and
comments (Section 3.2 of <xref target="Part1"/>) identifying the server and any significant
subproducts. The product tokens are listed in order of their significance
for identifying the application.
</t>
<figure><iref primary="true" item="Grammar" subitem="Server"/><iref primary="true" item="Grammar" subitem="Server-v"/><artwork type="abnf2616"><![CDATA[
Server = "Server" ":" OWS Server-v
Server-v = product
*( RWS ( product / comment ) )
]]></artwork></figure>
<t>
Example:
</t>
<figure><artwork type="example"><![CDATA[
Server: CERN/3.0 libwww/2.17
]]></artwork></figure>
<t>
If the response is being forwarded through a proxy, the proxy
application MUST NOT modify the Server response-header. Instead, it
MUST include a Via field (as described in Section 9.9 of <xref target="Part1"/>).
</t>
<t><list>
<t>
Note: Revealing the specific software version of the server might
allow the server machine to become more vulnerable to attacks
against software that is known to contain security holes. Server
implementors are encouraged to make this field a configurable
option.
</t>
</list></t>
</section>
<section title="User-Agent" anchor="header.user-agent">
<iref primary="true" item="User-Agent header"/>
<iref primary="true" item="Headers" subitem="User-Agent"/>
<t>
The "User-Agent" request-header field contains information about the
user agent originating the request. This is for statistical purposes,
the tracing of protocol violations, and automated recognition of user
agents for the sake of tailoring responses to avoid particular user
agent limitations.
</t>
<t>
User agents SHOULD include this field with requests. The field can contain
multiple product tokens (Section 6.3 of <xref target="Part1"/>) and comments (Section 3.2 of <xref target="Part1"/>)
identifying the agent and any subproducts which form a significant part of
the user agent. By convention, the product tokens are listed in order of
their significance for identifying the application.
</t>
<figure><iref primary="true" item="Grammar" subitem="User-Agent"/><iref primary="true" item="Grammar" subitem="User-Agent-v"/><artwork type="abnf2616"><![CDATA[
User-Agent = "User-Agent" ":" OWS User-Agent-v
User-Agent-v = product
*( RWS ( product / comment ) )
]]></artwork></figure>
<t>
Example:
</t>
<figure><artwork type="example"><![CDATA[
User-Agent: CERN-LineMode/2.15 libwww/2.17b3
]]></artwork></figure>
</section>
</section>
<section title="IANA Considerations" anchor="IANA.considerations">
<section title="Method Registry" anchor="method.registration">
<t>
The registration procedure for HTTP Methods is defined by
<xref target="method.registry"/> of this document.
</t>
<t>
The HTTP Method Registry shall be created at <eref target="http://www.iana.org/assignments/http-methods"/>
and be populated with the registrations below:
</t>
<!--AUTOGENERATED FROM extract-method-defs.xslt, do not edit manually-->
<texttable align="left" suppress-title="true" anchor="iana.method.registration.table">
<ttcol>Method</ttcol>
<ttcol>Safe</ttcol>
<ttcol>Reference</ttcol>
<c>CONNECT</c>
<c>no</c>
<c>
<xref target="CONNECT"/>
</c>
<c>DELETE</c>
<c>no</c>
<c>
<xref target="DELETE"/>
</c>
<c>GET</c>
<c>yes</c>
<c>
<xref target="GET"/>
</c>
<c>HEAD</c>
<c>yes</c>
<c>
<xref target="HEAD"/>
</c>
<c>OPTIONS</c>
<c>yes</c>
<c>
<xref target="OPTIONS"/>
</c>
<c>POST</c>
<c>no</c>
<c>
<xref target="POST"/>
</c>
<c>PUT</c>
<c>no</c>
<c>
<xref target="PUT"/>
</c>
<c>TRACE</c>
<c>yes</c>
<c>
<xref target="TRACE"/>
</c>
</texttable>
<!--(END)-->
</section>
<section title="Status Code Registry" anchor="status.code.registration">
<t>
The registration procedure for HTTP Status Codes -- previously defined
in Section 7.1 of <xref target="RFC2817"/> -- is now defined
by <xref target="status.code.registry"/> of this document.
</t>
<t>
The HTTP Status Code Registry located at <eref target="http://www.iana.org/assignments/http-status-codes"/>
shall be updated with the registrations below:
</t>
<!--AUTOGENERATED FROM extract-status-code-defs.xslt, do not edit manually-->
<texttable align="left" suppress-title="true" anchor="iana.status.code.registration.table">
<ttcol>Value</ttcol>
<ttcol>Description</ttcol>
<ttcol>Reference</ttcol>
<c>100</c>
<c>Continue</c>
<c>
<xref target="status.100"/>
</c>
<c>101</c>
<c>Switching Protocols</c>
<c>
<xref target="status.101"/>
</c>
<c>200</c>
<c>OK</c>
<c>
<xref target="status.200"/>
</c>
<c>201</c>
<c>Created</c>
<c>
<xref target="status.201"/>
</c>
<c>202</c>
<c>Accepted</c>
<c>
<xref target="status.202"/>
</c>
<c>203</c>
<c>Non-Authoritative Information</c>
<c>
<xref target="status.203"/>
</c>
<c>204</c>
<c>No Content</c>
<c>
<xref target="status.204"/>
</c>
<c>205</c>
<c>Reset Content</c>
<c>
<xref target="status.205"/>
</c>
<c>300</c>
<c>Multiple Choices</c>
<c>
<xref target="status.300"/>
</c>
<c>301</c>
<c>Moved Permanently</c>
<c>
<xref target="status.301"/>
</c>
<c>302</c>
<c>Found</c>
<c>
<xref target="status.302"/>
</c>
<c>303</c>
<c>See Other</c>
<c>
<xref target="status.303"/>
</c>
<c>305</c>
<c>Use Proxy</c>
<c>
<xref target="status.305"/>
</c>
<c>306</c>
<c>(Unused)</c>
<c>
<xref target="status.306"/>
</c>
<c>307</c>
<c>Temporary Redirect</c>
<c>
<xref target="status.307"/>
</c>
<c>400</c>
<c>Bad Request</c>
<c>
<xref target="status.400"/>
</c>
<c>402</c>
<c>Payment Required</c>
<c>
<xref target="status.402"/>
</c>
<c>403</c>
<c>Forbidden</c>
<c>
<xref target="status.403"/>
</c>
<c>404</c>
<c>Not Found</c>
<c>
<xref target="status.404"/>
</c>
<c>405</c>
<c>Method Not Allowed</c>
<c>
<xref target="status.405"/>
</c>
<c>406</c>
<c>Not Acceptable</c>
<c>
<xref target="status.406"/>
</c>
<c>407</c>
<c>Proxy Authentication Required</c>
<c>
<xref target="status.407"/>
</c>
<c>408</c>
<c>Request Timeout</c>
<c>
<xref target="status.408"/>
</c>
<c>409</c>
<c>Conflict</c>
<c>
<xref target="status.409"/>
</c>
<c>410</c>
<c>Gone</c>
<c>
<xref target="status.410"/>
</c>
<c>411</c>
<c>Length Required</c>
<c>
<xref target="status.411"/>
</c>
<c>413</c>
<c>Request Entity Too Large</c>
<c>
<xref target="status.413"/>
</c>
<c>414</c>
<c>URI Too Long</c>
<c>
<xref target="status.414"/>
</c>
<c>415</c>
<c>Unsupported Media Type</c>
<c>
<xref target="status.415"/>
</c>
<c>417</c>
<c>Expectation Failed</c>
<c>
<xref target="status.417"/>
</c>
<c>500</c>
<c>Internal Server Error</c>
<c>
<xref target="status.500"/>
</c>
<c>501</c>
<c>Not Implemented</c>
<c>
<xref target="status.501"/>
</c>
<c>502</c>
<c>Bad Gateway</c>
<c>
<xref target="status.502"/>
</c>
<c>503</c>
<c>Service Unavailable</c>
<c>
<xref target="status.503"/>
</c>
<c>504</c>
<c>Gateway Timeout</c>
<c>
<xref target="status.504"/>
</c>
<c>505</c>
<c>HTTP Version Not Supported</c>
<c>
<xref target="status.505"/>
</c>
</texttable>
<!--(END)-->
</section>
<section title="Header Field Registration" anchor="header.field.registration">
<t>
The Message Header Field Registry located at <eref target="http://www.iana.org/assignments/message-headers/message-header-index.html"/> shall be updated
with the permanent registrations below (see <xref target="RFC3864"/>):
</t>
<!--AUTOGENERATED FROM extract-header-defs.xslt, do not edit manually-->
<texttable align="left" suppress-title="true" anchor="iana.header.registration.table">
<ttcol>Header Field Name</ttcol>
<ttcol>Protocol</ttcol>
<ttcol>Status</ttcol>
<ttcol>Reference</ttcol>
<c>Allow</c>
<c>http</c>
<c>standard</c>
<c>
<xref target="header.allow"/>
</c>
<c>Expect</c>
<c>http</c>
<c>standard</c>
<c>
<xref target="header.expect"/>
</c>
<c>From</c>
<c>http</c>
<c>standard</c>
<c>
<xref target="header.from"/>
</c>
<c>Location</c>
<c>http</c>
<c>standard</c>
<c>
<xref target="header.location"/>
</c>
<c>Max-Forwards</c>
<c>http</c>
<c>standard</c>
<c>
<xref target="header.max-forwards"/>
</c>
<c>Referer</c>
<c>http</c>
<c>standard</c>
<c>
<xref target="header.referer"/>
</c>
<c>Retry-After</c>
<c>http</c>
<c>standard</c>
<c>
<xref target="header.retry-after"/>
</c>
<c>Server</c>
<c>http</c>
<c>standard</c>
<c>
<xref target="header.server"/>
</c>
<c>User-Agent</c>
<c>http</c>
<c>standard</c>
<c>
<xref target="header.user-agent"/>
</c>
</texttable>
<!--(END)-->
<t>
The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".
</t>
</section>
</section>
<section title="Security Considerations" anchor="security.considerations">
<t>
This section is meant to inform application developers, information
providers, and users of the security limitations in HTTP/1.1 as
described by this document. The discussion does not include
definitive solutions to the problems revealed, though it does make
some suggestions for reducing security risks.
</t>
<section title="Transfer of Sensitive Information" anchor="security.sensitive">
<t>
Like any generic data transfer protocol, HTTP cannot regulate the
content of the data that is transferred, nor is there any a priori
method of determining the sensitivity of any particular piece of
information within the context of any given request. Therefore,
applications SHOULD supply as much control over this information as
possible to the provider of that information. Four header fields are
worth special mention in this context: Server, Via, Referer and From.
</t>
<t>
Revealing the specific software version of the server might allow the
server machine to become more vulnerable to attacks against software
that is known to contain security holes. Implementors SHOULD make the
Server header field a configurable option.
</t>
<t>
Proxies which serve as a portal through a network firewall SHOULD
take special precautions regarding the transfer of header information
that identifies the hosts behind the firewall. In particular, they
SHOULD remove, or replace with sanitized versions, any Via fields
generated behind the firewall.
</t>
<t>
The Referer header allows reading patterns to be studied and reverse
links drawn. Although it can be very useful, its power can be abused
if user details are not separated from the information contained in
the Referer. Even when the personal information has been removed, the
Referer header might indicate a private document's URI whose
publication would be inappropriate.
</t>
<t>
The information sent in the From field might conflict with the user's
privacy interests or their site's security policy, and hence it
SHOULD NOT be transmitted without the user being able to disable,
enable, and modify the contents of the field. The user MUST be able
to set the contents of this field within a user preference or
application defaults configuration.
</t>
<t>
We suggest, though do not require, that a convenient toggle interface
be provided for the user to enable or disable the sending of From and
Referer information.
</t>
<t>
The User-Agent (<xref target="header.user-agent"/>) or Server (<xref target="header.server"/>) header
fields can sometimes be used to determine that a specific client or
server have a particular security hole which might be exploited.
Unfortunately, this same information is often used for other valuable
purposes for which HTTP currently has no better mechanism.
</t>
<t>
Some methods, like TRACE (<xref target="TRACE"/>), expose information
that was sent in request headers within the body of their response.
Clients SHOULD be careful with sensitive information, like Cookies,
Authorization credentials and other headers that might be used to
collect data from the client.
</t>
</section>
<section title="Encoding Sensitive Information in URIs" anchor="encoding.sensitive.information.in.uris">
<t>
Because the source of a link might be private information or might
reveal an otherwise private information source, it is strongly
recommended that the user be able to select whether or not the
Referer field is sent. For example, a browser client could have a
toggle switch for browsing openly/anonymously, which would
respectively enable/disable the sending of Referer and From
information.
</t>
<t>
Clients SHOULD NOT include a Referer header field in a (non-secure)
HTTP request if the referring page was transferred with a secure
protocol.
</t>
<t>
Authors of services SHOULD NOT use GET-based forms for the submission of
sensitive data because that data will be placed in the request-target. Many
existing servers, proxies, and user agents log or display the request-target
in places where it might be visible to third parties. Such services can
use POST-based form submission instead.
</t>
</section>
<section title="Location Headers and Spoofing" anchor="location.spoofing">
<t>
If a single server supports multiple organizations that do not trust
one another, then it MUST check the values of Location and Content-Location
headers in responses that are generated under control of
said organizations to make sure that they do not attempt to
invalidate resources over which they have no authority.
</t>
</section>
</section>
<section title="Acknowledgments" anchor="ack">
</section>
</middle>
<back>
<references title="Normative References">
<reference anchor="Part1">
<front>
<title abbrev="HTTP/1.1">HTTP/1.1, part 1: URIs, Connections, and Message Parsing</title>
<author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
<organization abbrev="Day Software">Day Software</organization>
<address><email>fielding@gbiv.com</email></address>
</author>
<author initials="J." surname="Gettys" fullname="Jim Gettys">
<organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
<address><email>jg@freedesktop.org</email></address>
</author>
<author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
<organization abbrev="HP">Hewlett-Packard Company</organization>
<address><email>JeffMogul@acm.org</email></address>
</author>
<author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>henrikn@microsoft.com</email></address>
</author>
<author initials="L." surname="Masinter" fullname="Larry Masinter">
<organization abbrev="Adobe Systems">Adobe Systems, Incorporated</organization>
<address><email>LMM@acm.org</email></address>
</author>
<author initials="P." surname="Leach" fullname="Paul J. Leach">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>paulle@microsoft.com</email></address>
</author>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
<address><email>timbl@w3.org</email></address>
</author>
<author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
<organization abbrev="W3C">World Wide Web Consortium</organization>
<address><email>ylafon@w3.org</email></address>
</author>
<author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
<organization abbrev="greenbytes">greenbytes GmbH</organization>
<address><email>julian.reschke@greenbytes.de</email></address>
</author>
<date month="August" year="2010"/>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p1-messaging-11"/>
</reference>
<reference anchor="Part3">
<front>
<title abbrev="HTTP/1.1">HTTP/1.1, part 3: Message Payload and Content Negotiation</title>
<author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
<organization abbrev="Day Software">Day Software</organization>
<address><email>fielding@gbiv.com</email></address>
</author>
<author initials="J." surname="Gettys" fullname="Jim Gettys">
<organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
<address><email>jg@freedesktop.org</email></address>
</author>
<author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
<organization abbrev="HP">Hewlett-Packard Company</organization>
<address><email>JeffMogul@acm.org</email></address>
</author>
<author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>henrikn@microsoft.com</email></address>
</author>
<author initials="L." surname="Masinter" fullname="Larry Masinter">
<organization abbrev="Adobe Systems">Adobe Systems, Incorporated</organization>
<address><email>LMM@acm.org</email></address>
</author>
<author initials="P." surname="Leach" fullname="Paul J. Leach">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>paulle@microsoft.com</email></address>
</author>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
<address><email>timbl@w3.org</email></address>
</author>
<author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
<organization abbrev="W3C">World Wide Web Consortium</organization>
<address><email>ylafon@w3.org</email></address>
</author>
<author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
<organization abbrev="greenbytes">greenbytes GmbH</organization>
<address><email>julian.reschke@greenbytes.de</email></address>
</author>
<date month="August" year="2010"/>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p3-payload-11"/>
</reference>
<reference anchor="Part4">
<front>
<title abbrev="HTTP/1.1">HTTP/1.1, part 4: Conditional Requests</title>
<author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
<organization abbrev="Day Software">Day Software</organization>
<address><email>fielding@gbiv.com</email></address>
</author>
<author initials="J." surname="Gettys" fullname="Jim Gettys">
<organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
<address><email>jg@freedesktop.org</email></address>
</author>
<author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
<organization abbrev="HP">Hewlett-Packard Company</organization>
<address><email>JeffMogul@acm.org</email></address>
</author>
<author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>henrikn@microsoft.com</email></address>
</author>
<author initials="L." surname="Masinter" fullname="Larry Masinter">
<organization abbrev="Adobe Systems">Adobe Systems, Incorporated</organization>
<address><email>LMM@acm.org</email></address>
</author>
<author initials="P." surname="Leach" fullname="Paul J. Leach">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>paulle@microsoft.com</email></address>
</author>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
<address><email>timbl@w3.org</email></address>
</author>
<author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
<organization abbrev="W3C">World Wide Web Consortium</organization>
<address><email>ylafon@w3.org</email></address>
</author>
<author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
<organization abbrev="greenbytes">greenbytes GmbH</organization>
<address><email>julian.reschke@greenbytes.de</email></address>
</author>
<date month="August" year="2010"/>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p4-conditional-11"/>
</reference>
<reference anchor="Part5">
<front>
<title abbrev="HTTP/1.1">HTTP/1.1, part 5: Range Requests and Partial Responses</title>
<author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
<organization abbrev="Day Software">Day Software</organization>
<address><email>fielding@gbiv.com</email></address>
</author>
<author initials="J." surname="Gettys" fullname="Jim Gettys">
<organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
<address><email>jg@freedesktop.org</email></address>
</author>
<author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
<organization abbrev="HP">Hewlett-Packard Company</organization>
<address><email>JeffMogul@acm.org</email></address>
</author>
<author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>henrikn@microsoft.com</email></address>
</author>
<author initials="L." surname="Masinter" fullname="Larry Masinter">
<organization abbrev="Adobe Systems">Adobe Systems, Incorporated</organization>
<address><email>LMM@acm.org</email></address>
</author>
<author initials="P." surname="Leach" fullname="Paul J. Leach">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>paulle@microsoft.com</email></address>
</author>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
<address><email>timbl@w3.org</email></address>
</author>
<author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
<organization abbrev="W3C">World Wide Web Consortium</organization>
<address><email>ylafon@w3.org</email></address>
</author>
<author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
<organization abbrev="greenbytes">greenbytes GmbH</organization>
<address><email>julian.reschke@greenbytes.de</email></address>
</author>
<date month="August" year="2010"/>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p5-range-11"/>
</reference>
<reference anchor="Part6">
<front>
<title abbrev="HTTP/1.1">HTTP/1.1, part 6: Caching</title>
<author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
<organization abbrev="Day Software">Day Software</organization>
<address><email>fielding@gbiv.com</email></address>
</author>
<author initials="J." surname="Gettys" fullname="Jim Gettys">
<organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
<address><email>jg@freedesktop.org</email></address>
</author>
<author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
<organization abbrev="HP">Hewlett-Packard Company</organization>
<address><email>JeffMogul@acm.org</email></address>
</author>
<author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>henrikn@microsoft.com</email></address>
</author>
<author initials="L." surname="Masinter" fullname="Larry Masinter">
<organization abbrev="Adobe Systems">Adobe Systems, Incorporated</organization>
<address><email>LMM@acm.org</email></address>
</author>
<author initials="P." surname="Leach" fullname="Paul J. Leach">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>paulle@microsoft.com</email></address>
</author>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
<address><email>timbl@w3.org</email></address>
</author>
<author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
<organization abbrev="W3C">World Wide Web Consortium</organization>
<address><email>ylafon@w3.org</email></address>
</author>
<author initials="M." surname="Nottingham" fullname="Mark Nottingham" role="editor">
<address><email>mnot@mnot.net</email></address>
</author>
<author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
<organization abbrev="greenbytes">greenbytes GmbH</organization>
<address><email>julian.reschke@greenbytes.de</email></address>
</author>
<date month="August" year="2010"/>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p6-cache-11"/>
</reference>
<reference anchor="Part7">
<front>
<title abbrev="HTTP/1.1">HTTP/1.1, part 7: Authentication</title>
<author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
<organization abbrev="Day Software">Day Software</organization>
<address><email>fielding@gbiv.com</email></address>
</author>
<author initials="J." surname="Gettys" fullname="Jim Gettys">
<organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
<address><email>jg@freedesktop.org</email></address>
</author>
<author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
<organization abbrev="HP">Hewlett-Packard Company</organization>
<address><email>JeffMogul@acm.org</email></address>
</author>
<author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>henrikn@microsoft.com</email></address>
</author>
<author initials="L." surname="Masinter" fullname="Larry Masinter">
<organization abbrev="Adobe Systems">Adobe Systems, Incorporated</organization>
<address><email>LMM@acm.org</email></address>
</author>
<author initials="P." surname="Leach" fullname="Paul J. Leach">
<organization abbrev="Microsoft">Microsoft Corporation</organization>
<address><email>paulle@microsoft.com</email></address>
</author>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
<address><email>timbl@w3.org</email></address>
</author>
<author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
<organization abbrev="W3C">World Wide Web Consortium</organization>
<address><email>ylafon@w3.org</email></address>
</author>
<author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
<organization abbrev="greenbytes">greenbytes GmbH</organization>
<address><email>julian.reschke@greenbytes.de</email></address>
</author>
<date month="August" year="2010"/>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p7-auth-11"/>
</reference>
<reference anchor="RFC2119">
<front>
<title>Key words for use in RFCs to Indicate Requirement Levels</title>
<author initials="S." surname="Bradner" fullname="Scott Bradner">
<organization>Harvard University</organization>
<address><email>sob@harvard.edu</email></address>
</author>
<date month="March" year="1997"/>
</front>
<seriesInfo name="BCP" value="14"/>
<seriesInfo name="RFC" value="2119"/>
</reference>
<reference anchor="RFC3986">
<front>
<title abbrev="URI Generic Syntax">Uniform Resource Identifier (URI): Generic Syntax</title>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
<address>
<email>timbl@w3.org</email>
<uri>http://www.w3.org/People/Berners-Lee/</uri>
</address>
</author>
<author initials="R." surname="Fielding" fullname="Roy T. Fielding">
<organization abbrev="Day Software">Day Software</organization>
<address>
<email>fielding@gbiv.com</email>
<uri>http://roy.gbiv.com/</uri>
</address>
</author>
<author initials="L." surname="Masinter" fullname="Larry Masinter">
<organization abbrev="Adobe Systems">Adobe Systems Incorporated</organization>
<address>
<email>LMM@acm.org</email>
<uri>http://larry.masinter.net/</uri>
</address>
</author>
<date month="January" year="2005"/>
</front>
<seriesInfo name="RFC" value="3986"/>
<seriesInfo name="STD" value="66"/>
</reference>
<reference anchor="RFC5234">
<front>
<title abbrev="ABNF for Syntax Specifications">Augmented BNF for Syntax Specifications: ABNF</title>
<author initials="D." surname="Crocker" fullname="Dave Crocker" role="editor">
<organization>Brandenburg InternetWorking</organization>
<address>
<email>dcrocker@bbiw.net</email>
</address>
</author>
<author initials="P." surname="Overell" fullname="Paul Overell">
<organization>THUS plc.</organization>
<address>
<email>paul.overell@thus.net</email>
</address>
</author>
<date month="January" year="2008"/>
</front>
<seriesInfo name="STD" value="68"/>
<seriesInfo name="RFC" value="5234"/>
</reference>
</references>
<references title="Informative References">
<reference anchor="RFC1945">
<front>
<title abbrev="HTTP/1.0">Hypertext Transfer Protocol -- HTTP/1.0</title>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization>MIT, Laboratory for Computer Science</organization>
<address><email>timbl@w3.org</email></address>
</author>
<author initials="R.T." surname="Fielding" fullname="Roy T. Fielding">
<organization>University of California, Irvine, Department of Information and Computer Science</organization>
<address><email>fielding@ics.uci.edu</email></address>
</author>
<author initials="H.F." surname="Nielsen" fullname="Henrik Frystyk Nielsen">
<organization>W3 Consortium, MIT Laboratory for Computer Science</organization>
<address><email>frystyk@w3.org</email></address>
</author>
<date month="May" year="1996"/>
</front>
<seriesInfo name="RFC" value="1945"/>
</reference>
<reference anchor="RFC2068">
<front>
<title abbrev="HTTP/1.1">Hypertext Transfer Protocol -- HTTP/1.1</title>
<author initials="R." surname="Fielding" fullname="Roy T. Fielding">
<organization>University of California, Irvine, Department of Information and Computer Science</organization>
<address><email>fielding@ics.uci.edu</email></address>
</author>
<author initials="J." surname="Gettys" fullname="Jim Gettys">
<organization>MIT Laboratory for Computer Science</organization>
<address><email>jg@w3.org</email></address>
</author>
<author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
<organization>Digital Equipment Corporation, Western Research Laboratory</organization>
<address><email>mogul@wrl.dec.com</email></address>
</author>
<author initials="H." surname="Nielsen" fullname="Henrik Frystyk Nielsen">
<organization>MIT Laboratory for Computer Science</organization>
<address><email>frystyk@w3.org</email></address>
</author>
<author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
<organization>MIT Laboratory for Computer Science</organization>
<address><email>timbl@w3.org</email></address>
</author>
<date month="January" year="1997"/>
</front>
<seriesInfo name="RFC" value="2068"/>
</reference>
<reference anchor="RFC2616">
<front>
<title>Hypertext Transfer Protocol -- HTTP/1.1</title>
<author initials="R." surname="Fielding" fullname="R. Fielding">
<organization>University of California, Irvine</organization>
<address><email>fielding@ics.uci.edu</email></address>
</author>
<author initials="J." surname="Gettys" fullname="J. Gettys">
<organization>W3C</organization>
<address><email>jg@w3.org</email></address>
</author>
<author initials="J." surname="Mogul" fullname="J. Mogul">
<organization>Compaq Computer Corporation</organization>
<address><email>mogul@wrl.dec.com</email></address>
</author>
<author initials="H." surname="Frystyk" fullname="H. Frystyk">
<organization>MIT Laboratory for Computer Science</organization>
<address><email>frystyk@w3.org</email></address>
</author>
<author initials="L." surname="Masinter" fullname="L. Masinter">
<organization>Xerox Corporation</organization>
<address><email>masinter@parc.xerox.com</email></address>
</author>
<author initials="P." surname="Leach" fullname="P. Leach">
<organization>Microsoft Corporation</organization>
<address><email>paulle@microsoft.com</email></address>
</author>
<author initials="T." surname="Berners-Lee" fullname="T. Berners-Lee">
<organization>W3C</organization>
<address><email>timbl@w3.org</email></address>
</author>
<date month="June" year="1999"/>
</front>
<seriesInfo name="RFC" value="2616"/>
</reference>
<reference anchor="RFC2817">
<front>
<title>Upgrading to TLS Within HTTP/1.1</title>
<author initials="R." surname="Khare" fullname="R. Khare">
<organization>4K Associates / UC Irvine</organization>
<address><email>rohit@4K-associates.com</email></address>
</author>
<author initials="S." surname="Lawrence" fullname="S. Lawrence">
<organization>Agranat Systems, Inc.</organization>
<address><email>lawrence@agranat.com</email></address>
</author>
<date year="2000" month="May"/>
</front>
<seriesInfo name="RFC" value="2817"/>
</reference>
<reference anchor="RFC3864">
<front>
<title>Registration Procedures for Message Header Fields</title>
<author initials="G." surname="Klyne" fullname="G. Klyne">
<organization>Nine by Nine</organization>
<address><email>GK-IETF@ninebynine.org</email></address>
</author>
<author initials="M." surname="Nottingham" fullname="M. Nottingham">
<organization>BEA Systems</organization>
<address><email>mnot@pobox.com</email></address>
</author>
<author initials="J." surname="Mogul" fullname="J. Mogul">
<organization>HP Labs</organization>
<address><email>JeffMogul@acm.org</email></address>
</author>
<date year="2004" month="September"/>
</front>
<seriesInfo name="BCP" value="90"/>
<seriesInfo name="RFC" value="3864"/>
</reference>
<reference anchor="RFC5226">
<front>
<title>Guidelines for Writing an IANA Considerations Section in RFCs</title>
<author initials="T." surname="Narten" fullname="T. Narten">
<organization>IBM</organization>
<address><email>narten@us.ibm.com</email></address>
</author>
<author initials="H." surname="Alvestrand" fullname="H. Alvestrand">
<organization>Google</organization>
<address><email>Harald@Alvestrand.no</email></address>
</author>
<date year="2008" month="May"/>
</front>
<seriesInfo name="BCP" value="26"/>
<seriesInfo name="RFC" value="5226"/>
</reference>
<reference anchor="RFC5322">
<front>
<title>Internet Message Format</title>
<author initials="P." surname="Resnick" fullname="P. Resnick">
<organization>Qualcomm Incorporated</organization>
</author>
<date year="2008" month="October"/>
</front>
<seriesInfo name="RFC" value="5322"/>
</reference>
</references>
<section title="Changes from RFC 2616" anchor="changes.from.rfc.2616">
<t>
This document takes over the Status Code Registry, previously defined
in Section 7.1 of <xref target="RFC2817"/>.
(<xref target="status.code.registry"/>)
</t>
<t>
Clarify definition of POST.
(<xref target="POST"/>)
</t>
<t>
Failed to consider that there are
many other request methods that are safe to automatically redirect,
and further that the user agent is able to make that determination
based on the request method semantics.
(Sections <xref format="counter" target="status.301"/>,
<xref format="counter" target="status.302"/> and
<xref format="counter" target="status.307"/>)
</t>
<t>
Deprecate 305 Use Proxy status code, because user agents did not implement it.
It used to indicate that the target resource must be accessed through the
proxy given by the Location field. The Location field gave the URI of the
proxy. The recipient was expected to repeat this single request via the proxy.
(<xref target="status.305"/>)
</t>
<t>
Reclassify Allow header as response header, removing the option to
specify it in a PUT request.
Relax the server requirement on the contents of the Allow header and
remove requirement on clients to always trust the header value.
(<xref target="header.allow"/>)
</t>
<t>
Correct syntax of Location header to allow URI references (including
relative references and fragments), as referred symbol "absoluteURI" wasn't
what was expected, and add some clarifications as to when use of fragments
would not be appropriate.
(<xref target="header.location"/>)
</t>
<t>
Allow Referer value of "about:blank" as alternative to not specifying it.
(<xref target="header.referer"/>)
</t>
<t>
In the description of the Server header, the Via field
was described as a SHOULD. The requirement was and is stated
correctly in the description of the Via header in Section 9.9 of <xref target="Part1"/>.
(<xref target="header.server"/>)
</t>
</section>
<section title="Collected ABNF" anchor="collected.abnf">
<figure>
<artwork type="abnf" name="p2-semantics.parsed-abnf"><![CDATA[
Accept = <Accept, defined in [Part3], Section 6.1>
Accept-Charset = <Accept-Charset, defined in [Part3], Section 6.2>
Accept-Encoding = <Accept-Encoding, defined in [Part3], Section 6.3>
Accept-Language = <Accept-Language, defined in [Part3], Section 6.4>
Accept-Ranges = <Accept-Ranges, defined in [Part5], Section 5.1>
Age = <Age, defined in [Part6], Section 3.1>
Allow = "Allow:" OWS Allow-v
Allow-v = [ ( "," / Method ) *( OWS "," [ OWS Method ] ) ]
Authorization = <Authorization, defined in [Part7], Section 3.1>
ETag = <ETag, defined in [Part4], Section 6.1>
Expect = "Expect:" OWS Expect-v
Expect-v = *( "," OWS ) expectation *( OWS "," [ OWS expectation ] )
From = "From:" OWS From-v
From-v = mailbox
HTTP-date = <HTTP-date, defined in [Part1], Section 6.1>
Host = <Host, defined in [Part1], Section 2.6>
If-Match = <If-Match, defined in [Part4], Section 6.2>
If-Modified-Since =
<If-Modified-Since, defined in [Part4], Section 6.3>
If-None-Match = <If-None-Match, defined in [Part4], Section 6.4>
If-Range = <If-Range, defined in [Part5], Section 5.3>
If-Unmodified-Since =
<If-Unmodified-Since, defined in [Part4], Section 6.5>
Location = "Location:" OWS Location-v
Location-v = URI-reference
Max-Forwards = "Max-Forwards:" OWS Max-Forwards-v
Max-Forwards-v = 1*DIGIT
Method = %x4F.50.54.49.4F.4E.53 ; OPTIONS
/ %x47.45.54 ; GET
/ %x48.45.41.44 ; HEAD
/ %x50.4F.53.54 ; POST
/ %x50.55.54 ; PUT
/ %x44.45.4C.45.54.45 ; DELETE
/ %x54.52.41.43.45 ; TRACE
/ %x43.4F.4E.4E.45.43.54 ; CONNECT
/ extension-method
OWS = <OWS, defined in [Part1], Section 1.2.2>
Proxy-Authenticate =
<Proxy-Authenticate, defined in [Part7], Section 3.2>
Proxy-Authorization =
<Proxy-Authorization, defined in [Part7], Section 3.3>
RWS = <RWS, defined in [Part1], Section 1.2.2>
Range = <Range, defined in [Part5], Section 5.4>
Reason-Phrase = *( WSP / VCHAR / obs-text )
Referer = "Referer:" OWS Referer-v
Referer-v = absolute-URI / partial-URI
Retry-After = "Retry-After:" OWS Retry-After-v
Retry-After-v = HTTP-date / delta-seconds
Server = "Server:" OWS Server-v
Server-v = product *( RWS ( product / comment ) )
Status-Code = "100" / "101" / "200" / "201" / "202" / "203" / "204" /
"205" / "206" / "300" / "301" / "302" / "303" / "304" / "305" /
"307" / "400" / "401" / "402" / "403" / "404" / "405" / "406" /
"407" / "408" / "409" / "410" / "411" / "412" / "413" / "414" /
"415" / "416" / "417" / "500" / "501" / "502" / "503" / "504" /
"505" / extension-code
TE = <TE, defined in [Part1], Section 9.5>
URI-reference = <URI-reference, defined in [Part1], Section 2.6>
User-Agent = "User-Agent:" OWS User-Agent-v
User-Agent-v = product *( RWS ( product / comment ) )
Vary = <Vary, defined in [Part6], Section 3.5>
WWW-Authenticate =
<WWW-Authenticate, defined in [Part7], Section 3.4>
absolute-URI = <absolute-URI, defined in [Part1], Section 2.6>
comment = <comment, defined in [Part1], Section 3.2>
delta-seconds = 1*DIGIT
expect-params = ";" token [ "=" ( token / quoted-string ) ]
expectation = "100-continue" / expectation-extension
expectation-extension = token [ "=" ( token / quoted-string )
*expect-params ]
extension-code = 3DIGIT
extension-method = token
mailbox = <mailbox, defined in [RFC5322], Section 3.4>
obs-text = <obs-text, defined in [Part1], Section 1.2.2>
partial-URI = <partial-URI, defined in [Part1], Section 2.6>
product = <product, defined in [Part1], Section 6.3>
quoted-string = <quoted-string, defined in [Part1], Section 1.2.2>
request-header = Accept / Accept-Charset / Accept-Encoding /
Accept-Language / Authorization / Expect / From / Host / If-Match /
If-Modified-Since / If-None-Match / If-Range / If-Unmodified-Since /
Max-Forwards / Proxy-Authorization / Range / Referer / TE /
User-Agent
response-header = Accept-Ranges / Age / Allow / ETag / Location /
Proxy-Authenticate / Retry-After / Server / Vary / WWW-Authenticate
token = <token, defined in [Part1], Section 1.2.2>
]]></artwork>
</figure>
<figure><preamble>ABNF diagnostics:</preamble><artwork type="inline"><![CDATA[
; Reason-Phrase defined but not used
; Status-Code defined but not used
; request-header defined but not used
; response-header defined but not used
]]></artwork></figure></section>
<section title="Change Log (to be removed by RFC Editor before publication)" anchor="change.log">
<section title="Since RFC2616">
<t>
Extracted relevant partitions from <xref target="RFC2616"/>.
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-00">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/5"/>:
"Via is a MUST"
(<eref target="http://purl.org/NET/http-errata#via-must"/>)
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/6"/>:
"Fragments allowed in Location"
(<eref target="http://purl.org/NET/http-errata#location-fragments"/>)
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/10"/>:
"Safe Methods vs Redirection"
(<eref target="http://purl.org/NET/http-errata#saferedirect"/>)
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/17"/>:
"Revise description of the POST method"
(<eref target="http://purl.org/NET/http-errata#post"/>)
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/35"/>:
"Normative and Informative references"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/42"/>:
"RFC2606 Compliance"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/65"/>:
"Informative references"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/84"/>:
"Redundant cross-references"
</t>
</list>
</t>
<t>
Other changes:
<list style="symbols">
<t>
Move definitions of 304 and 412 condition codes to <xref target="Part4"/>
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-01">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/21"/>:
"PUT side effects"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/91"/>:
"Duplicate Host header requirements"
</t>
</list>
</t>
<t>
Ongoing work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
<list style="symbols">
<t>
Move "Product Tokens" section (back) into Part 1, as "token" is used
in the definition of the Upgrade header.
</t>
<t>
Add explicit references to BNF syntax and rules imported from other parts of the specification.
</t>
<t>
Copy definition of delta-seconds from Part6 instead of referencing it.
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-02" anchor="changes.since.02">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/24"/>:
"Requiring Allow in 405 responses"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/59"/>:
"Status Code Registry"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/61"/>:
"Redirection vs. Location"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/70"/>:
"Cacheability of 303 response"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/76"/>:
"305 Use Proxy"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/105"/>:
"Classification for Allow header"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/112"/>:
"PUT - 'store under' vs 'store at'"
</t>
</list>
</t>
<t>
Ongoing work on IANA Message Header Registration (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/40"/>):
<list style="symbols">
<t>
Reference RFC 3984, and update header registrations for headers defined
in this document.
</t>
</list>
</t>
<t>
Ongoing work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
<list style="symbols">
<t>
Replace string literals when the string really is case-sensitive (method).
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-03" anchor="changes.since.03">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/98"/>:
"OPTIONS request bodies"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/119"/>:
"Description of CONNECT should refer to RFC2817"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/125"/>:
"Location Content-Location reference request/response mixup"
</t>
</list>
</t>
<t>
Ongoing work on Method Registry (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/72"/>):
<list style="symbols">
<t>
Added initial proposal for registration process, plus initial
content (non-HTTP/1.1 methods to be added by a separate specification).
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-04" anchor="changes.since.04">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/103"/>:
"Content-*"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/132"/>:
"RFC 2822 is updated by RFC 5322"
</t>
</list>
</t>
<t>
Ongoing work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
<list style="symbols">
<t>
Use "/" instead of "|" for alternatives.
</t>
<t>
Introduce new ABNF rules for "bad" whitespace ("BWS"), optional
whitespace ("OWS") and required whitespace ("RWS").
</t>
<t>
Rewrite ABNFs to spell out whitespace rules, factor out
header value format definitions.
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-05" anchor="changes.since.05">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/94"/>:
"Reason-Phrase BNF"
</t>
</list>
</t>
<t>
Final work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
<list style="symbols">
<t>
Add appendix containing collected and expanded ABNF, reorganize ABNF introduction.
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-06" anchor="changes.since.06">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/144"/>:
"Clarify when Referer is sent"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/164"/>:
"status codes vs methods"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/170"/>:
"Do not require "updates" relation for specs that register status codes or method names"
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-07" anchor="changes.since.07">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/27"/>:
"Idempotency"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/33"/>:
"TRACE security considerations"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/110"/>:
"Clarify rules for determining what entities a response carries"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/140"/>:
"update note citing RFC 1945 and 2068"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/182"/>:
"update note about redirect limit"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/191"/>:
"Location header ABNF should use 'URI'"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/192"/>:
"fragments in Location vs status 303"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/198"/>:
"move IANA registrations for optional status codes"
</t>
</list>
</t>
<t>
Partly resolved issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/171"/>:
"Are OPTIONS and TRACE safe?"
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-08" anchor="changes.since.08">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/10"/>:
"Safe Methods vs Redirection" (we missed the introduction to the 3xx
status codes when fixing this previously)
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-09" anchor="changes.since.09">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/43"/>:
"Fragment combination / precedence during redirects"
</t>
</list>
</t>
<t>
Partly resolved issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/185"/>:
"Location header payload handling"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/196"/>:
"Term for the requested resource's URI"
</t>
</list>
</t>
</section>
<section title="Since draft-ietf-httpbis-p2-semantics-10" anchor="changes.since.10">
<t>
Closed issues:
<list style="symbols">
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/69"/>:
"Clarify 'Requested Variant'"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/109"/>:
"Clarify entity / representation / variant terminology"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/139"/>:
"Methods and Caching"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/190"/>:
"OPTIONS vs Max-Forwards"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/199"/>:
"Status codes and caching"
</t>
<t>
<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/220"/>:
"consider removing the 'changes from 2068' sections"
</t>
</list>
</t>
</section>
</section>
</back>
</rfc>| PAFTECH AB 2003-2026 | 2026-04-24 00:50:11 |