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Changeset 1629 for draft-ietf-httpbis
- Timestamp:
- 28/03/12 16:01:47 (9 years ago)
- Location:
- draft-ietf-httpbis/experiment
- Files:
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- 3 edited
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p1-messaging.html (modified) (21 diffs)
-
p2-semantics.html (modified) (105 diffs)
-
p2-semantics.xml (modified) (1 diff)
Legend:
- Unmodified
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- Removed
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draft-ietf-httpbis/experiment/p1-messaging.html
r1628 r1629 757 757 <p id="rfc.section.1.p.1">The Hypertext Transfer Protocol (HTTP) is an application-level request/response protocol that uses extensible semantics and 758 758 MIME-like message payloads for flexible interaction with network-based hypertext information systems. HTTP relies upon the 759 Uniform Resource Identifier (URI) standard <a href="#RFC3986" id="rfc.xref.RFC3986.1"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a> to indicate the target resource (<a href="#target-resource" title="Identifying a Target Resource">Section 5.1</a>) and relationships between resources. Messages are passed in a format similar to that used by Internet mail <a href="#RFC5322" id="rfc.xref.RFC5322.1"><cite title="Internet Message Format">[RFC5322]</cite></a> and the Multipurpose Internet Mail Extensions (MIME) <a href="#RFC2045" id="rfc.xref.RFC2045.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies">[RFC2045]</cite></a> (see <a href="p2-semantics.html#differences.between.http.and.mime" title=" Differences between HTTP and MIME">Appendix A</a> of <a href="#Part2" id="rfc.xref.Part2.1"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a> for the differences between HTTP and MIME messages).759 Uniform Resource Identifier (URI) standard <a href="#RFC3986" id="rfc.xref.RFC3986.1"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a> to indicate the target resource (<a href="#target-resource" title="Identifying a Target Resource">Section 5.1</a>) and relationships between resources. Messages are passed in a format similar to that used by Internet mail <a href="#RFC5322" id="rfc.xref.RFC5322.1"><cite title="Internet Message Format">[RFC5322]</cite></a> and the Multipurpose Internet Mail Extensions (MIME) <a href="#RFC2045" id="rfc.xref.RFC2045.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies">[RFC2045]</cite></a> (see <a href="p2-semantics.html#differences.between.http.and.mime" title="ERROR: Anchor 'differences.between.http.and.mime' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'differences.between.http.and.mime' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.1"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a> for the differences between HTTP and MIME messages). 760 760 </p> 761 761 <p id="rfc.section.1.p.2">HTTP is a generic interface protocol for information systems. It is designed to hide the details of how a service is implemented … … 910 910 or an intranet-to-Internet privacy filter. Such transformations are presumed to be desired by the client (or client organization) 911 911 that selected the proxy and are beyond the scope of this specification. However, when a proxy is not intended to transform 912 a given message, we use the term "<dfn>non-transforming proxy</dfn>" to target requirements that preserve HTTP message semantics. See <a href="p2-semantics.html#status.203" title=" 203 Non-Authoritative Information">Section 4.4.4</a> of <a href="#Part2" id="rfc.xref.Part2.2"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a> and <a href="p6-cache.html#header.warning" title="Warning">Section 3.6</a> of <a href="#Part6" id="rfc.xref.Part6.1"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a> for status and warning codes related to transformations.912 a given message, we use the term "<dfn>non-transforming proxy</dfn>" to target requirements that preserve HTTP message semantics. See <a href="p2-semantics.html#status.203" title="ERROR: Anchor 'status.203' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.203' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.2"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a> and <a href="p6-cache.html#header.warning" title="Warning">Section 3.6</a> of <a href="#Part6" id="rfc.xref.Part6.1"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a> for status and warning codes related to transformations. 913 913 </p> 914 914 <p id="rfc.section.2.3.p.7"><span id="rfc.iref.g.13"></span><span id="rfc.iref.r.4"></span> <span id="rfc.iref.a.1"></span> A "<dfn>gateway</dfn>" (a.k.a., "<dfn>reverse proxy</dfn>") is a receiving agent that acts as a layer above some other server(s) and translates the received requests to the underlying … … 1078 1078 </p> 1079 1079 <p id="rfc.section.2.7.1.p.6">When an "http" URI is used within a context that calls for access to the indicated resource, a client <em class="bcp14">MAY</em> attempt access by resolving the host to an IP address, establishing a TCP connection to that address on the indicated port, 1080 and sending an HTTP request message (<a href="#http.message" title="Message Format">Section 3</a>) containing the URI's identifying data (<a href="#message.routing" title="Message Routing">Section 5</a>) to the server. If the server responds to that request with a non-interim HTTP response message, as described in <a href="p2-semantics.html#status.code.and.reason.phrase" title=" Status Code and Reason Phrase">Section 4</a> of <a href="#Part2" id="rfc.xref.Part2.3"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>, then that response is considered an authoritative answer to the client's request.1080 and sending an HTTP request message (<a href="#http.message" title="Message Format">Section 3</a>) containing the URI's identifying data (<a href="#message.routing" title="Message Routing">Section 5</a>) to the server. If the server responds to that request with a non-interim HTTP response message, as described in <a href="p2-semantics.html#status.code.and.reason.phrase" title="ERROR: Anchor 'status.code.and.reason.phrase' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.code.and.reason.phrase' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.3"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>, then that response is considered an authoritative answer to the client's request. 1081 1081 </p> 1082 1082 <p id="rfc.section.2.7.1.p.7">Although HTTP is independent of the transport protocol, the "http" scheme is specific to TCP-based services because the name … … 1174 1174 </div> 1175 1175 <div id="rfc.figure.u.14"></div><pre class="inline"><span id="rfc.iref.g.28"></span> <a href="#method" class="smpl">method</a> = <a href="#rule.token.separators" class="smpl">token</a> 1176 </pre><p id="rfc.section.3.1.1.p.5">The methods defined by this specification can be found in <a href="p2-semantics.html#methods" title=" Methods">Section 2</a> of <a href="#Part2" id="rfc.xref.Part2.4"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>, along with information regarding the HTTP method registry and considerations for defining new methods.1176 </pre><p id="rfc.section.3.1.1.p.5">The methods defined by this specification can be found in <a href="p2-semantics.html#methods" title="ERROR: Anchor 'methods' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'methods' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.4"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>, along with information regarding the HTTP method registry and considerations for defining new methods. 1177 1177 </p> 1178 1178 <div id="rfc.iref.r.6"></div> … … 1189 1189 <p id="rfc.section.3.1.1.p.9">HTTP does not place a pre-defined limit on the length of a request-line. A server that receives a method longer than any that 1190 1190 it implements <em class="bcp14">SHOULD</em> respond with either a 405 (Not Allowed), if it is an origin server, or a 501 (Not Implemented) status code. A server <em class="bcp14">MUST</em> be prepared to receive URIs of unbounded length and respond with the 414 (URI Too Long) status code if the received request-target 1191 would be longer than the server wishes to handle (see <a href="p2-semantics.html#status.414" title=" 414 URI Too Long">Section 4.6.12</a> of <a href="#Part2" id="rfc.xref.Part2.5"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>).1191 would be longer than the server wishes to handle (see <a href="p2-semantics.html#status.414" title="ERROR: Anchor 'status.414' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.414' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.5"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). 1192 1192 </p> 1193 1193 <p id="rfc.section.3.1.1.p.10">Various ad-hoc limitations on request-line length are found in practice. It is <em class="bcp14">RECOMMENDED</em> that all HTTP senders and recipients support, at a minimum, request-line lengths of up to 8000 octets. … … 1199 1199 <div id="rfc.figure.u.15"></div><pre class="inline"><span id="rfc.iref.g.29"></span> <a href="#status.line" class="smpl">status-line</a> = <a href="#http.version" class="smpl">HTTP-version</a> <a href="#core.rules" class="smpl">SP</a> <a href="#status-code" class="smpl">status-code</a> <a href="#core.rules" class="smpl">SP</a> <a href="#reason-phrase" class="smpl">reason-phrase</a> <a href="#core.rules" class="smpl">CRLF</a> 1200 1200 </pre><div id="status-code"> 1201 <p id="rfc.section.3.1.2.p.3">The status-code element is a 3-digit integer result code of the attempt to understand and satisfy the request. See <a href="p2-semantics.html#status.code.and.reason.phrase" title=" Status Code and Reason Phrase">Section 4</a> of <a href="#Part2" id="rfc.xref.Part2.6"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a> for further information, such as the list of status codes defined by this specification, the IANA registry, and considerations1201 <p id="rfc.section.3.1.2.p.3">The status-code element is a 3-digit integer result code of the attempt to understand and satisfy the request. See <a href="p2-semantics.html#status.code.and.reason.phrase" title="ERROR: Anchor 'status.code.and.reason.phrase' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.code.and.reason.phrase' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.6"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a> for further information, such as the list of status codes defined by this specification, the IANA registry, and considerations 1202 1202 for new status codes. 1203 1203 </p> … … 1223 1223 ; see <a href="#field.parsing" title="Field Parsing">Section 3.2.2</a> 1224 1224 </pre><p id="rfc.section.3.2.p.3">The field-name token labels the corresponding field-value as having the semantics defined by that header field. For example, 1225 the Date header field is defined in <a href="p2-semantics.html#header.date" title=" Date">Section 11.2</a> of <a href="#Part2" id="rfc.xref.Part2.7"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a> as containing the origination timestamp for the message in which it appears.1225 the Date header field is defined in <a href="p2-semantics.html#header.date" title="ERROR: Anchor 'header.date' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'header.date' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.7"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a> as containing the origination timestamp for the message in which it appears. 1226 1226 </p> 1227 1227 <p id="rfc.section.3.2.p.4">HTTP header fields are fully extensible: there is no limit on the introduction of new field names, each presumably defining … … 1231 1231 them. 1232 1232 </p> 1233 <p id="rfc.section.3.2.p.5">New HTTP header fields <em class="bcp14">SHOULD</em> be registered with IANA according to the procedures in <a href="p2-semantics.html#considerations.for.creating.header.fields" title=" Considerations for Creating Header Fields">Section 3.1</a> of <a href="#Part2" id="rfc.xref.Part2.8"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>. Unrecognized header fields <em class="bcp14">MUST</em> be forwarded by a proxy unless the field-name is listed in the Connection header field (<a href="#header.connection" id="rfc.xref.header.connection.3" title="Connection">Section 6.1</a>) or the proxy is specifically configured to block or otherwise transform such fields. Unrecognized header fields <em class="bcp14">SHOULD</em> be ignored by other recipients.1233 <p id="rfc.section.3.2.p.5">New HTTP header fields <em class="bcp14">SHOULD</em> be registered with IANA according to the procedures in <a href="p2-semantics.html#considerations.for.creating.header.fields" title="ERROR: Anchor 'considerations.for.creating.header.fields' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'considerations.for.creating.header.fields' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.8"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>. Unrecognized header fields <em class="bcp14">MUST</em> be forwarded by a proxy unless the field-name is listed in the Connection header field (<a href="#header.connection" id="rfc.xref.header.connection.3" title="Connection">Section 6.1</a>) or the proxy is specifically configured to block or otherwise transform such fields. Unrecognized header fields <em class="bcp14">SHOULD</em> be ignored by other recipients. 1234 1234 </p> 1235 1235 <p id="rfc.section.3.2.p.6">The order in which header fields with differing field names are received is not significant. However, it is "good practice" … … 1418 1418 <p id="rfc.section.3.3.1.p.6">If more than one Transfer-Encoding header field is present in a message, the multiple field-values <em class="bcp14">MUST</em> be combined into one field-value, according to the algorithm defined in <a href="#header.fields" title="Header Fields">Section 3.2</a>, before determining the message body length. 1419 1419 </p> 1420 <p id="rfc.section.3.3.1.p.7">Unlike Content-Encoding (<a href="p2-semantics.html#content.codings" title=" Content Codings">Section 7.2</a> of <a href="#Part2" id="rfc.xref.Part2.9"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>), Transfer-Encoding is a property of the message, not of the payload, and thus <em class="bcp14">MAY</em> be added or removed by any implementation along the request/response chain. Additional information about the encoding parameters <em class="bcp14">MAY</em> be provided by other header fields not defined by this specification.1420 <p id="rfc.section.3.3.1.p.7">Unlike Content-Encoding (<a href="p2-semantics.html#content.codings" title="ERROR: Anchor 'content.codings' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'content.codings' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.9"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>), Transfer-Encoding is a property of the message, not of the payload, and thus <em class="bcp14">MAY</em> be added or removed by any implementation along the request/response chain. Additional information about the encoding parameters <em class="bcp14">MAY</em> be provided by other header fields not defined by this specification. 1421 1421 </p> 1422 1422 <p id="rfc.section.3.3.1.p.8">Transfer-Encoding <em class="bcp14">MAY</em> be sent in a response to a HEAD request or in a 304 response to a GET request, neither of which includes a message body, to … … 1725 1725 </p> 1726 1726 <h3 id="rfc.section.4.3.1"><a href="#rfc.section.4.3.1">4.3.1</a> <a id="quality.values" href="#quality.values">Quality Values</a></h3> 1727 <p id="rfc.section.4.3.1.p.1">Both transfer codings (TE request header field, <a href="#header.te" id="rfc.xref.header.te.3" title="TE">Section 4.3</a>) and content negotiation (<a href="p2-semantics.html#content.negotiation" title=" Content Negotiation">Section 10</a> of <a href="#Part2" id="rfc.xref.Part2.10"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) use short "floating point" numbers to indicate the relative importance ("weight") of various negotiable parameters. A weight1727 <p id="rfc.section.4.3.1.p.1">Both transfer codings (TE request header field, <a href="#header.te" id="rfc.xref.header.te.3" title="TE">Section 4.3</a>) and content negotiation (<a href="p2-semantics.html#content.negotiation" title="ERROR: Anchor 'content.negotiation' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'content.negotiation' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.10"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) use short "floating point" numbers to indicate the relative importance ("weight") of various negotiable parameters. A weight 1728 1728 is normalized to a real number in the range 0 through 1, where 0 is the minimum and 1 the maximum value. If a parameter has 1729 1729 a quality value of 0, then content with this parameter is "not acceptable" for the client. HTTP/1.1 applications <em class="bcp14">MUST NOT</em> generate more than three digits after the decimal point. User configuration of these values <em class="bcp14">SHOULD</em> also be limited in this fashion. … … 1826 1826 </p> 1827 1827 <div id="authority-form"> 1828 <p id="rfc.section.5.3.p.13"><span id="rfc.iref.a.3"></span> The authority-form of request-target is only used for CONNECT requests (<a href="p2-semantics.html#CONNECT" title=" CONNECT">Section 2.3.8</a> of <a href="#Part2" id="rfc.xref.Part2.12"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). When making a CONNECT request to establish a tunnel through one or more proxies, a client <em class="bcp14">MUST</em> send only the target URI's authority component (excluding any userinfo) as the request-target. For example,1828 <p id="rfc.section.5.3.p.13"><span id="rfc.iref.a.3"></span> The authority-form of request-target is only used for CONNECT requests (<a href="p2-semantics.html#CONNECT" title="ERROR: Anchor 'CONNECT' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'CONNECT' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.12"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). When making a CONNECT request to establish a tunnel through one or more proxies, a client <em class="bcp14">MUST</em> send only the target URI's authority component (excluding any userinfo) as the request-target. For example, 1829 1829 </p> 1830 1830 </div> 1831 1831 <div id="rfc.figure.u.49"></div><pre class="text2">CONNECT www.example.com:80 HTTP/1.1 1832 1832 </pre><div id="asterisk-form"> 1833 <p id="rfc.section.5.3.p.15"><span id="rfc.iref.a.4"></span> The asterisk-form of request-target is only used for a server-wide OPTIONS request (<a href="p2-semantics.html#OPTIONS" title=" OPTIONS">Section 2.3.1</a> of <a href="#Part2" id="rfc.xref.Part2.13"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). When a client wishes to request OPTIONS for the server as a whole, as opposed to a specific named resource of that server,1833 <p id="rfc.section.5.3.p.15"><span id="rfc.iref.a.4"></span> The asterisk-form of request-target is only used for a server-wide OPTIONS request (<a href="p2-semantics.html#OPTIONS" title="ERROR: Anchor 'OPTIONS' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'OPTIONS' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.13"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). When a client wishes to request OPTIONS for the server as a whole, as opposed to a specific named resource of that server, 1834 1834 the client <em class="bcp14">MUST</em> send only "*" (%x2A) as the request-target. For example, 1835 1835 </p> … … 1992 1992 messages. Hence, it relies on the order of response arrival to correspond exactly to the order in which requests are made 1993 1993 on the same connection. More than one response message per request only occurs when one or more informational responses (1xx, 1994 see <a href="p2-semantics.html#status.1xx" title=" Informational 1xx">Section 4.3</a> of <a href="#Part2" id="rfc.xref.Part2.15"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) precede a final response to the same request.1994 see <a href="p2-semantics.html#status.1xx" title="ERROR: Anchor 'status.1xx' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.1xx' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.15"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) precede a final response to the same request. 1995 1995 </p> 1996 1996 <p id="rfc.section.5.7.p.2">A client that uses persistent connections and sends more than one request per connection <em class="bcp14">MUST</em> maintain a list of outstanding requests in the order sent on that connection and <em class="bcp14">MUST</em> associate each received response message to the highest ordered request that has not yet received a final (non-1xx) response. … … 2137 2137 <p id="rfc.section.6.3.2.2.p.2">Clients which assume persistent connections and pipeline immediately after connection establishment <em class="bcp14">SHOULD</em> be prepared to retry their connection if the first pipelined attempt fails. If a client does such a retry, it <em class="bcp14">MUST NOT</em> pipeline before it knows the connection is persistent. Clients <em class="bcp14">MUST</em> also be prepared to resend their requests if the server closes the connection before sending all of the corresponding responses. 2138 2138 </p> 2139 <p id="rfc.section.6.3.2.2.p.3">Clients <em class="bcp14">SHOULD NOT</em> pipeline requests using non-idempotent request methods or non-idempotent sequences of request methods (see <a href="p2-semantics.html#idempotent.methods" title=" Idempotent Methods">Section 2.1.2</a> of <a href="#Part2" id="rfc.xref.Part2.16"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). Otherwise, a premature termination of the transport connection could lead to indeterminate results. A client wishing to2139 <p id="rfc.section.6.3.2.2.p.3">Clients <em class="bcp14">SHOULD NOT</em> pipeline requests using non-idempotent request methods or non-idempotent sequences of request methods (see <a href="p2-semantics.html#idempotent.methods" title="ERROR: Anchor 'idempotent.methods' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'idempotent.methods' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.16"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). Otherwise, a premature termination of the transport connection could lead to indeterminate results. A client wishing to 2140 2140 send a non-idempotent request <em class="bcp14">SHOULD</em> wait to send that request until it has received the response status line for the previous request. 2141 2141 </p> … … 2167 2167 <h3 id="rfc.section.6.3.4"><a href="#rfc.section.6.3.4">6.3.4</a> <a id="persistent.retrying.requests" href="#persistent.retrying.requests">Retrying Requests</a></h3> 2168 2168 <p id="rfc.section.6.3.4.p.1">Senders can close the transport connection at any time. Therefore, clients, servers, and proxies <em class="bcp14">MUST</em> be able to recover from asynchronous close events. Client software <em class="bcp14">MAY</em> reopen the transport connection and retransmit the aborted sequence of requests without user interaction so long as the request 2169 sequence is idempotent (see <a href="p2-semantics.html#idempotent.methods" title=" Idempotent Methods">Section 2.1.2</a> of <a href="#Part2" id="rfc.xref.Part2.17"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). Non-idempotent request methods or sequences <em class="bcp14">MUST NOT</em> be automatically retried, although user agents <em class="bcp14">MAY</em> offer a human operator the choice of retrying the request(s). Confirmation by user-agent software with semantic understanding2169 sequence is idempotent (see <a href="p2-semantics.html#idempotent.methods" title="ERROR: Anchor 'idempotent.methods' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'idempotent.methods' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.17"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). Non-idempotent request methods or sequences <em class="bcp14">MUST NOT</em> be automatically retried, although user agents <em class="bcp14">MAY</em> offer a human operator the choice of retrying the request(s). Confirmation by user-agent software with semantic understanding 2170 2170 of the application <em class="bcp14">MAY</em> substitute for user confirmation. The automatic retry <em class="bcp14">SHOULD NOT</em> be repeated if the second sequence of requests fails. 2171 2171 </p> … … 2180 2180 </p> 2181 2181 <h3 id="rfc.section.6.4.3"><a href="#rfc.section.6.4.3">6.4.3</a> <a id="use.of.the.100.status" href="#use.of.the.100.status">Use of the 100 (Continue) Status</a></h3> 2182 <p id="rfc.section.6.4.3.p.1">The purpose of the 100 (Continue) status code (see <a href="p2-semantics.html#status.100" title=" 100 Continue">Section 4.3.1</a> of <a href="#Part2" id="rfc.xref.Part2.18"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) is to allow a client that is sending a request message with a request body to determine if the origin server is willing2182 <p id="rfc.section.6.4.3.p.1">The purpose of the 100 (Continue) status code (see <a href="p2-semantics.html#status.100" title="ERROR: Anchor 'status.100' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.100' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.18"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) is to allow a client that is sending a request message with a request body to determine if the origin server is willing 2183 2183 to accept the request (based on the request header fields) before the client sends the request body. In some cases, it might 2184 2184 either be inappropriate or highly inefficient for the client to send the body if the server will reject the message without … … 2187 2187 <p id="rfc.section.6.4.3.p.2">Requirements for HTTP/1.1 clients: </p> 2188 2188 <ul> 2189 <li>If a client will wait for a 100 (Continue) response before sending the request body, it <em class="bcp14">MUST</em> send an Expect header field (<a href="p2-semantics.html#header.expect" title="E xpect">Section 11.3</a> of <a href="#Part2" id="rfc.xref.Part2.19"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) with the "100-continue" expectation.2190 </li> 2191 <li>A client <em class="bcp14">MUST NOT</em> send an Expect header field (<a href="p2-semantics.html#header.expect" title="E xpect">Section 11.3</a> of <a href="#Part2" id="rfc.xref.Part2.20"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) with the "100-continue" expectation if it does not intend to send a request body.2189 <li>If a client will wait for a 100 (Continue) response before sending the request body, it <em class="bcp14">MUST</em> send an Expect header field (<a href="p2-semantics.html#header.expect" title="ERROR: Anchor 'header.expect' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'header.expect' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.19"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) with the "100-continue" expectation. 2190 </li> 2191 <li>A client <em class="bcp14">MUST NOT</em> send an Expect header field (<a href="p2-semantics.html#header.expect" title="ERROR: Anchor 'header.expect' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'header.expect' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.20"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) with the "100-continue" expectation if it does not intend to send a request body. 2192 2192 </li> 2193 2193 </ul> … … 2233 2233 <li>A proxy <em class="bcp14">MUST NOT</em> forward a 100 (Continue) response if the request message was received from an HTTP/1.0 (or earlier) client and did not include 2234 2234 an Expect header field with the "100-continue" expectation. This requirement overrides the general rule for forwarding of 2235 1xx responses (see <a href="p2-semantics.html#status.1xx" title=" Informational 1xx">Section 4.3</a> of <a href="#Part2" id="rfc.xref.Part2.21"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>).2235 1xx responses (see <a href="p2-semantics.html#status.1xx" title="ERROR: Anchor 'status.1xx' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.1xx' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.21"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). 2236 2236 </li> 2237 2237 </ul> … … 2270 2270 </p> 2271 2271 <p id="rfc.section.6.5.p.8">The Upgrade header field cannot be used to indicate a switch to a protocol on a different connection. For that purpose, it 2272 is more appropriate to use a 3xx redirection response (<a href="p2-semantics.html#status.3xx" title=" Redirection 3xx">Section 4.5</a> of <a href="#Part2" id="rfc.xref.Part2.22"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>).2272 is more appropriate to use a 3xx redirection response (<a href="p2-semantics.html#status.3xx" title="ERROR: Anchor 'status.3xx' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.3xx' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.22"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). 2273 2273 </p> 2274 2274 <p id="rfc.section.6.5.p.9">Servers <em class="bcp14">MUST</em> include the "Upgrade" header field in 101 (Switching Protocols) responses to indicate which protocol(s) are being switched … … 2534 2534 <li>Pointer to specification text</li> 2535 2535 </ul> 2536 <p id="rfc.section.7.4.p.3">Names of transfer codings <em class="bcp14">MUST NOT</em> overlap with names of content codings (<a href="p2-semantics.html#content.codings" title=" Content Codings">Section 7.2</a> of <a href="#Part2" id="rfc.xref.Part2.23"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) unless the encoding transformation is identical, as it is the case for the compression codings defined in <a href="#compression.codings" title="Compression Codings">Section 4.2</a>.2536 <p id="rfc.section.7.4.p.3">Names of transfer codings <em class="bcp14">MUST NOT</em> overlap with names of content codings (<a href="p2-semantics.html#content.codings" title="ERROR: Anchor 'content.codings' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'content.codings' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.23"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) unless the encoding transformation is identical, as it is the case for the compression codings defined in <a href="#compression.codings" title="Compression Codings">Section 4.2</a>. 2537 2537 </p> 2538 2538 <p id="rfc.section.7.4.p.4">Values to be added to this name space require IETF Review (see <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a> of <a href="#RFC5226" id="rfc.xref.RFC5226.1"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>), and <em class="bcp14">MUST</em> conform to the purpose of transfer coding defined in this section. … … 2694 2694 that most implementations will choose substantially higher limits. 2695 2695 </p> 2696 <p id="rfc.section.8.6.p.3">This specification also provides a way for servers to reject messages that have request-targets that are too long (<a href="p2-semantics.html#status.414" title=" 414 URI Too Long">Section 4.6.12</a> of <a href="#Part2" id="rfc.xref.Part2.24"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) or request entities that are too large (<a href="p2-semantics.html#status.4xx" title="Client Error 4xx">Section 4.6</a> of <a href="#Part2" id="rfc.xref.Part2.25"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>).2696 <p id="rfc.section.8.6.p.3">This specification also provides a way for servers to reject messages that have request-targets that are too long (<a href="p2-semantics.html#status.414" title="ERROR: Anchor 'status.414' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.414' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.24"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) or request entities that are too large (<a href="p2-semantics.html#status.4xx" title="ERROR: Anchor 'status.4xx' not found in p2-semantics.xml.">Appendix ERROR: Anchor 'status.4xx' in Part2 not found in source file 'p2-semantics.xml'.</a> of <a href="#Part2" id="rfc.xref.Part2.25"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). 2697 2697 </p> 2698 2698 <p id="rfc.section.8.6.p.4">Other fields (including but not limited to request methods, response status phrases, header field-names, and body chunks) <em class="bcp14">SHOULD</em> be limited by implementations carefully, so as to not impede interoperability. … … 3746 3746 <li><em>Pad1995</em> <a href="#rfc.xref.Pad1995.1">6.3.1</a>, <a href="#Pad1995"><b>10.2</b></a></li> 3747 3747 <li><em>Part2</em> <a href="#rfc.xref.Part2.1">1</a>, <a href="#rfc.xref.Part2.2">2.3</a>, <a href="#rfc.xref.Part2.3">2.7.1</a>, <a href="#rfc.xref.Part2.4">3.1.1</a>, <a href="#rfc.xref.Part2.5">3.1.1</a>, <a href="#rfc.xref.Part2.6">3.1.2</a>, <a href="#rfc.xref.Part2.7">3.2</a>, <a href="#rfc.xref.Part2.8">3.2</a>, <a href="#rfc.xref.Part2.9">3.3.1</a>, <a href="#rfc.xref.Part2.10">4.3.1</a>, <a href="#rfc.xref.Part2.11">5.1</a>, <a href="#rfc.xref.Part2.12">5.3</a>, <a href="#rfc.xref.Part2.13">5.3</a>, <a href="#rfc.xref.Part2.14">5.6.2</a>, <a href="#rfc.xref.Part2.15">5.7</a>, <a href="#rfc.xref.Part2.16">6.3.2.2</a>, <a href="#rfc.xref.Part2.17">6.3.4</a>, <a href="#rfc.xref.Part2.18">6.4.3</a>, <a href="#rfc.xref.Part2.19">6.4.3</a>, <a href="#rfc.xref.Part2.20">6.4.3</a>, <a href="#rfc.xref.Part2.21">6.4.3</a>, <a href="#rfc.xref.Part2.22">6.5</a>, <a href="#rfc.xref.Part2.23">7.4</a>, <a href="#rfc.xref.Part2.24">8.6</a>, <a href="#rfc.xref.Part2.25">8.6</a>, <a href="#Part2"><b>10.1</b></a><ul> 3748 <li><em> Section 2</em> <a href="#rfc.xref.Part2.4">3.1.1</a></li>3749 <li><em> Section 2.1.2</em> <a href="#rfc.xref.Part2.16">6.3.2.2</a>, <a href="#rfc.xref.Part2.17">6.3.4</a></li>3750 <li><em> Section 2.3.1</em> <a href="#rfc.xref.Part2.13">5.3</a></li>3751 <li><em> Section 2.3.8</em> <a href="#rfc.xref.Part2.12">5.3</a></li>3752 <li><em> Section 3.1</em> <a href="#rfc.xref.Part2.8">3.2</a></li>3753 <li><em> Section 4</em> <a href="#rfc.xref.Part2.3">2.7.1</a>, <a href="#rfc.xref.Part2.6">3.1.2</a></li>3754 <li><em> Section 4.3</em> <a href="#rfc.xref.Part2.15">5.7</a>, <a href="#rfc.xref.Part2.21">6.4.3</a></li>3755 <li><em> Section 4.3.1</em> <a href="#rfc.xref.Part2.18">6.4.3</a></li>3756 <li><em> Section 4.4.4</em> <a href="#rfc.xref.Part2.2">2.3</a></li>3757 <li><em> Section 4.5</em> <a href="#rfc.xref.Part2.22">6.5</a></li>3758 <li><em> Section 4.6</em> <a href="#rfc.xref.Part2.25">8.6</a></li>3759 <li><em> Section 4.6.12</em> <a href="#rfc.xref.Part2.5">3.1.1</a>, <a href="#rfc.xref.Part2.24">8.6</a></li>3760 <li><em> Section 7.2</em> <a href="#rfc.xref.Part2.9">3.3.1</a>, <a href="#rfc.xref.Part2.23">7.4</a></li>3761 <li><em> Section 10</em> <a href="#rfc.xref.Part2.10">4.3.1</a></li>3762 <li><em> Section 11.2</em> <a href="#rfc.xref.Part2.7">3.2</a></li>3763 <li><em> Section 11.3</em> <a href="#rfc.xref.Part2.19">6.4.3</a>, <a href="#rfc.xref.Part2.20">6.4.3</a></li>3764 <li><em>Appendix A</em> <a href="#rfc.xref.Part2.1">1</a></li>3748 <li><em>Appendix </em> <a href="#rfc.xref.Part2.1">1</a></li> 3749 <li><em>Appendix </em> <a href="#rfc.xref.Part2.2">2.3</a></li> 3750 <li><em>Appendix </em> <a href="#rfc.xref.Part2.3">2.7.1</a>, <a href="#rfc.xref.Part2.6">3.1.2</a></li> 3751 <li><em>Appendix </em> <a href="#rfc.xref.Part2.4">3.1.1</a></li> 3752 <li><em>Appendix </em> <a href="#rfc.xref.Part2.5">3.1.1</a>, <a href="#rfc.xref.Part2.24">8.6</a></li> 3753 <li><em>Appendix </em> <a href="#rfc.xref.Part2.7">3.2</a></li> 3754 <li><em>Appendix </em> <a href="#rfc.xref.Part2.8">3.2</a></li> 3755 <li><em>Appendix </em> <a href="#rfc.xref.Part2.9">3.3.1</a>, <a href="#rfc.xref.Part2.23">7.4</a></li> 3756 <li><em>Appendix </em> <a href="#rfc.xref.Part2.10">4.3.1</a></li> 3757 <li><em>Appendix </em> <a href="#rfc.xref.Part2.12">5.3</a></li> 3758 <li><em>Appendix </em> <a href="#rfc.xref.Part2.13">5.3</a></li> 3759 <li><em>Appendix </em> <a href="#rfc.xref.Part2.15">5.7</a>, <a href="#rfc.xref.Part2.21">6.4.3</a></li> 3760 <li><em>Appendix </em> <a href="#rfc.xref.Part2.16">6.3.2.2</a>, <a href="#rfc.xref.Part2.17">6.3.4</a></li> 3761 <li><em>Appendix </em> <a href="#rfc.xref.Part2.18">6.4.3</a></li> 3762 <li><em>Appendix </em> <a href="#rfc.xref.Part2.19">6.4.3</a>, <a href="#rfc.xref.Part2.20">6.4.3</a></li> 3763 <li><em>Appendix </em> <a href="#rfc.xref.Part2.22">6.5</a></li> 3764 <li><em>Appendix </em> <a href="#rfc.xref.Part2.25">8.6</a></li> 3765 3765 </ul> 3766 3766 </li> -
draft-ietf-httpbis/experiment/p2-semantics.html
r1627 r1629 488 488 <link rel="Chapter" title="5 Representation" href="#rfc.section.5"> 489 489 <link rel="Chapter" title="6 Common Protocol Parameters" href="#rfc.section.6"> 490 <link rel="Chapter" title="7 Protocol Parameters" href="#rfc.section.7"> 491 <link rel="Chapter" title="8 Payload" href="#rfc.section.8"> 492 <link rel="Chapter" title="9 Representation" href="#rfc.section.9"> 493 <link rel="Chapter" title="10 Content Negotiation" href="#rfc.section.10"> 494 <link rel="Chapter" title="11 Header Field Definitions" href="#rfc.section.11"> 495 <link rel="Chapter" title="12 IANA Considerations" href="#rfc.section.12"> 496 <link rel="Chapter" title="13 Security Considerations" href="#rfc.section.13"> 497 <link rel="Chapter" title="14 Acknowledgments" href="#rfc.section.14"> 498 <link rel="Chapter" href="#rfc.section.15" title="15 References"> 490 <link rel="Chapter" title="7 Payload" href="#rfc.section.7"> 491 <link rel="Chapter" title="8 Representation" href="#rfc.section.8"> 492 <link rel="Chapter" title="9 Content Negotiation" href="#rfc.section.9"> 493 <link rel="Chapter" title="10 Header Field Definitions" href="#rfc.section.10"> 494 <link rel="Chapter" title="11 IANA Considerations" href="#rfc.section.11"> 495 <link rel="Chapter" title="12 Security Considerations" href="#rfc.section.12"> 496 <link rel="Chapter" title="13 Acknowledgments" href="#rfc.section.13"> 497 <link rel="Chapter" href="#rfc.section.14" title="14 References"> 499 498 <link rel="Appendix" title="A Differences between HTTP and MIME" href="#rfc.section.A"> 500 499 <link rel="Appendix" title="B Additional Features" href="#rfc.section.B"> … … 699 698 <li>6.1 <a href="#http.date">Date/Time Formats</a></li> 700 699 <li>6.2 <a href="#product.tokens">Product Tokens</a></li> 701 </ul> 702 </li> 703 <li>7. <a href="#protocol.parameters">Protocol Parameters</a><ul> 704 <li>7.1 <a href="#character.sets">Character Encodings (charset)</a></li> 705 <li>7.2 <a href="#content.codings">Content Codings</a><ul> 706 <li>7.2.1 <a href="#content.coding.registry">Content Coding Registry</a></li> 700 <li>6.3 <a href="#character.sets">Character Encodings (charset)</a></li> 701 <li>6.4 <a href="#content.codings">Content Codings</a><ul> 702 <li>6.4.1 <a href="#content.coding.registry">Content Coding Registry</a></li> 707 703 </ul> 708 704 </li> 709 <li> 7.3 <a href="#media.types">Media Types</a><ul>710 <li> 7.3.1 <a href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></li>711 <li> 7.3.2 <a href="#multipart.types">Multipart Types</a></li>705 <li>6.5 <a href="#media.types">Media Types</a><ul> 706 <li>6.5.1 <a href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></li> 707 <li>6.5.2 <a href="#multipart.types">Multipart Types</a></li> 712 708 </ul> 713 709 </li> 714 <li> 7.4 <a href="#language.tags">Language Tags</a></li>710 <li>6.6 <a href="#language.tags">Language Tags</a></li> 715 711 </ul> 716 712 </li> 717 <li> 8. <a href="#payload">Payload</a><ul>718 <li> 8.1 <a href="#payload.header.fields">Payload Header Fields</a></li>719 <li> 8.2 <a href="#payload.body">Payload Body</a></li>713 <li>7. <a href="#payload">Payload</a><ul> 714 <li>7.1 <a href="#payload.header.fields">Payload Header Fields</a></li> 715 <li>7.2 <a href="#payload.body">Payload Body</a></li> 720 716 </ul> 721 717 </li> 722 <li> 9. <a href="#representation-TODO">Representation</a><ul>723 <li> 9.1 <a href="#representation.header.fields">Representation Header Fields</a></li>724 <li> 9.2 <a href="#representation.data">Representation Data</a></li>718 <li>8. <a href="#representation-TODO">Representation</a><ul> 719 <li>8.1 <a href="#representation.header.fields">Representation Header Fields</a></li> 720 <li>8.2 <a href="#representation.data">Representation Data</a></li> 725 721 </ul> 726 722 </li> 727 <li> 10. <a href="#content.negotiation">Content Negotiation</a><ul>728 <li> 10.1 <a href="#server-driven.negotiation">Server-driven Negotiation</a></li>729 <li> 10.2 <a href="#agent-driven.negotiation">Agent-driven Negotiation</a></li>723 <li>9. <a href="#content.negotiation">Content Negotiation</a><ul> 724 <li>9.1 <a href="#server-driven.negotiation">Server-driven Negotiation</a></li> 725 <li>9.2 <a href="#agent-driven.negotiation">Agent-driven Negotiation</a></li> 730 726 </ul> 731 727 </li> 732 <li>1 1. <a href="#header.field.definitions">Header Field Definitions</a><ul>733 <li>1 1.1 <a href="#header.allow">Allow</a></li>734 <li>1 1.2 <a href="#header.date">Date</a></li>735 <li>1 1.3 <a href="#header.expect">Expect</a></li>736 <li>1 1.4 <a href="#header.from">From</a></li>737 <li>1 1.5 <a href="#header.location">Location</a></li>738 <li>1 1.6 <a href="#header.max-forwards">Max-Forwards</a></li>739 <li>1 1.7 <a href="#header.referer">Referer</a></li>740 <li>1 1.8 <a href="#header.retry-after">Retry-After</a></li>741 <li>1 1.9 <a href="#header.server">Server</a></li>742 <li>1 1.10 <a href="#header.user-agent">User-Agent</a></li>743 <li>1 1.11 <a href="#header.accept">Accept</a></li>744 <li>1 1.12 <a href="#header.accept-charset">Accept-Charset</a></li>745 <li>1 1.13 <a href="#header.accept-encoding">Accept-Encoding</a></li>746 <li>1 1.14 <a href="#header.accept-language">Accept-Language</a></li>747 <li>1 1.15 <a href="#header.content-encoding">Content-Encoding</a></li>748 <li>1 1.16 <a href="#header.content-language">Content-Language</a></li>749 <li>1 1.17 <a href="#header.content-location">Content-Location</a></li>750 <li>1 1.18 <a href="#header.content-type">Content-Type</a></li>728 <li>10. <a href="#header.field.definitions">Header Field Definitions</a><ul> 729 <li>10.1 <a href="#header.allow">Allow</a></li> 730 <li>10.2 <a href="#header.date">Date</a></li> 731 <li>10.3 <a href="#header.expect">Expect</a></li> 732 <li>10.4 <a href="#header.from">From</a></li> 733 <li>10.5 <a href="#header.location">Location</a></li> 734 <li>10.6 <a href="#header.max-forwards">Max-Forwards</a></li> 735 <li>10.7 <a href="#header.referer">Referer</a></li> 736 <li>10.8 <a href="#header.retry-after">Retry-After</a></li> 737 <li>10.9 <a href="#header.server">Server</a></li> 738 <li>10.10 <a href="#header.user-agent">User-Agent</a></li> 739 <li>10.11 <a href="#header.accept">Accept</a></li> 740 <li>10.12 <a href="#header.accept-charset">Accept-Charset</a></li> 741 <li>10.13 <a href="#header.accept-encoding">Accept-Encoding</a></li> 742 <li>10.14 <a href="#header.accept-language">Accept-Language</a></li> 743 <li>10.15 <a href="#header.content-encoding">Content-Encoding</a></li> 744 <li>10.16 <a href="#header.content-language">Content-Language</a></li> 745 <li>10.17 <a href="#header.content-location">Content-Location</a></li> 746 <li>10.18 <a href="#header.content-type">Content-Type</a></li> 751 747 </ul> 752 748 </li> 753 <li>1 2. <a href="#IANA.considerations">IANA Considerations</a><ul>754 <li>1 2.1 <a href="#method.registration">Method Registry</a></li>755 <li>1 2.2 <a href="#status.code.registration">Status Code Registry</a></li>756 <li>1 2.3 <a href="#header.field.registration">Header Field Registration</a></li>757 <li>1 2.4 <a href="#content.coding.registration">Content Coding Registry</a></li>749 <li>11. <a href="#IANA.considerations">IANA Considerations</a><ul> 750 <li>11.1 <a href="#method.registration">Method Registry</a></li> 751 <li>11.2 <a href="#status.code.registration">Status Code Registry</a></li> 752 <li>11.3 <a href="#header.field.registration">Header Field Registration</a></li> 753 <li>11.4 <a href="#content.coding.registration">Content Coding Registry</a></li> 758 754 </ul> 759 755 </li> 760 <li>1 3. <a href="#security.considerations">Security Considerations</a><ul>761 <li>1 3.1 <a href="#security.sensitive">Transfer of Sensitive Information</a></li>762 <li>1 3.2 <a href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></li>763 <li>1 3.3 <a href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></li>764 <li>1 3.4 <a href="#rfc.section.13.4">Security Considerations for CONNECT</a></li>765 <li>1 3.5 <a href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></li>756 <li>12. <a href="#security.considerations">Security Considerations</a><ul> 757 <li>12.1 <a href="#security.sensitive">Transfer of Sensitive Information</a></li> 758 <li>12.2 <a href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></li> 759 <li>12.3 <a href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></li> 760 <li>12.4 <a href="#rfc.section.12.4">Security Considerations for CONNECT</a></li> 761 <li>12.5 <a href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></li> 766 762 </ul> 767 763 </li> 768 <li>1 4. <a href="#acks">Acknowledgments</a></li>769 <li>1 5. <a href="#rfc.references">References</a><ul>770 <li>1 5.1 <a href="#rfc.references.1">Normative References</a></li>771 <li>1 5.2 <a href="#rfc.references.2">Informative References</a></li>764 <li>13. <a href="#acks">Acknowledgments</a></li> 765 <li>14. <a href="#rfc.references">References</a><ul> 766 <li>14.1 <a href="#rfc.references.1">Normative References</a></li> 767 <li>14.2 <a href="#rfc.references.2">Informative References</a></li> 772 768 </ul> 773 769 </li> … … 909 905 </p> 910 906 <div id="rfc.figure.u.3"></div><pre class="inline"><span id="rfc.iref.g.1"></span> <a href="#methods" class="smpl">method</a> = <a href="#core.rules" class="smpl">token</a> 911 </pre><p id="rfc.section.2.p.3">The list of methods allowed by a resource can be specified in an Allow header field (<a href="#header.allow" id="rfc.xref.header.allow.1" title="Allow">Section 1 1.1</a>). The status code of the response always notifies the client whether a method is currently allowed on a resource, since the907 </pre><p id="rfc.section.2.p.3">The list of methods allowed by a resource can be specified in an Allow header field (<a href="#header.allow" id="rfc.xref.header.allow.1" title="Allow">Section 10.1</a>). The status code of the response always notifies the client whether a method is currently allowed on a resource, since the 912 908 set of allowed methods can change dynamically. An origin server <em class="bcp14">SHOULD</em> respond with the status code 405 (Method Not Allowed) if the method is known by the origin server but not allowed for the 913 909 resource, and 501 (Not Implemented) if the method is unrecognized or not implemented by the origin server. The methods GET … … 989 985 but might be defined by future extensions to HTTP. Content negotiation <em class="bcp14">MAY</em> be used to select the appropriate response format. If no response body is included, the response <em class="bcp14">MUST</em> include a Content-Length field with a field-value of "0". 990 986 </p> 991 <p id="rfc.section.2.3.1.p.7">The Max-Forwards header field <em class="bcp14">MAY</em> be used to target a specific proxy in the request chain (see <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.1" title="Max-Forwards">Section 1 1.6</a>). If no Max-Forwards field is present in the request, then the forwarded request <em class="bcp14">MUST NOT</em> include a Max-Forwards field.987 <p id="rfc.section.2.3.1.p.7">The Max-Forwards header field <em class="bcp14">MAY</em> be used to target a specific proxy in the request chain (see <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.1" title="Max-Forwards">Section 10.6</a>). If no Max-Forwards field is present in the request, then the forwarded request <em class="bcp14">MUST NOT</em> include a Max-Forwards field. 992 988 </p> 993 989 <h3 id="rfc.section.2.3.2"><a href="#rfc.section.2.3.2">2.3.2</a> <a id="GET" href="#GET">GET</a></h3> … … 1013 1009 <p id="rfc.section.2.3.2.p.6">The response to a GET request is cacheable and <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD requests (see <a href="#Part6" id="rfc.xref.Part6.2"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>). 1014 1010 </p> 1015 <p id="rfc.section.2.3.2.p.7">See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section 1 3.2</a> for security considerations when used for forms.1011 <p id="rfc.section.2.3.2.p.7">See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section 12.2</a> for security considerations when used for forms. 1016 1012 </p> 1017 1013 <h3 id="rfc.section.2.3.3"><a href="#rfc.section.2.3.3">2.3.3</a> <a id="HEAD" href="#HEAD">HEAD</a></h3> … … 1047 1043 </p> 1048 1044 <p id="rfc.section.2.3.4.p.4">If a resource has been created on the origin server, the response <em class="bcp14">SHOULD</em> be 201 (Created) and contain a representation which describes the status of the request and refers to the new resource, and 1049 a Location header field (see <a href="#header.location" id="rfc.xref.header.location.1" title="Location">Section 1 1.5</a>).1050 </p> 1051 <p id="rfc.section.2.3.4.p.5">Responses to POST requests are only cacheable when they include explicit freshness information (see <a href="p6-cache.html#calculating.freshness.lifetime" title="Calculating Freshness Lifetime">Section 2.3.1</a> of <a href="#Part6" id="rfc.xref.Part6.4"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>). A cached POST response with a Content-Location header field (see <a href="#header.content-location" id="rfc.xref.header.content-location.1" title="Content-Location">Section 1 1.17</a>) whose value is the effective Request URI <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD requests.1045 a Location header field (see <a href="#header.location" id="rfc.xref.header.location.1" title="Location">Section 10.5</a>). 1046 </p> 1047 <p id="rfc.section.2.3.4.p.5">Responses to POST requests are only cacheable when they include explicit freshness information (see <a href="p6-cache.html#calculating.freshness.lifetime" title="Calculating Freshness Lifetime">Section 2.3.1</a> of <a href="#Part6" id="rfc.xref.Part6.4"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>). A cached POST response with a Content-Location header field (see <a href="#header.content-location" id="rfc.xref.header.content-location.1" title="Content-Location">Section 10.17</a>) whose value is the effective Request URI <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD requests. 1052 1048 </p> 1053 1049 <p id="rfc.section.2.3.4.p.6">Note that POST caching is not widely implemented. However, the 303 (See Other) response can be used to direct the user agent … … 1137 1133 <div id="rfc.iref.m.7"></div> 1138 1134 <p id="rfc.section.2.3.7.p.1">The TRACE method requests a remote, application-layer loop-back of the request message. The final recipient of the request <em class="bcp14">SHOULD</em> reflect the message received back to the client as the message body of a 200 (OK) response. The final recipient is either 1139 the origin server or the first proxy to receive a Max-Forwards value of zero (0) in the request (see <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.2" title="Max-Forwards">Section 1 1.6</a>). A TRACE request <em class="bcp14">MUST NOT</em> include a message body.1135 the origin server or the first proxy to receive a Max-Forwards value of zero (0) in the request (see <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.2" title="Max-Forwards">Section 10.6</a>). A TRACE request <em class="bcp14">MUST NOT</em> include a message body. 1140 1136 </p> 1141 1137 <p id="rfc.section.2.3.7.p.2">TRACE allows the client to see what is being received at the other end of the request chain and use that data for testing … … 1212 1208 double quotes will likely cause unnecessary confusion. 1213 1209 </p> 1214 <p id="rfc.section.3.1.p.8">Many header fields use a format including (case-insensitively) named parameters (for instance, Content-Type, defined in <a href="#header.content-type" id="rfc.xref.header.content-type.1" title="Content-Type">Section 1 1.18</a>). Allowing both unquoted (token) and quoted (quoted-string) syntax for the parameter value enables recipients to use existing1210 <p id="rfc.section.3.1.p.8">Many header fields use a format including (case-insensitively) named parameters (for instance, Content-Type, defined in <a href="#header.content-type" id="rfc.xref.header.content-type.1" title="Content-Type">Section 10.18</a>). Allowing both unquoted (token) and quoted (quoted-string) syntax for the parameter value enables recipients to use existing 1215 1211 parser components. When allowing both forms, the meaning of a parameter value ought to be independent of the syntax used for 1216 it (for an example, see the notes on parameter handling for media types in <a href="#media.types" title="Media Types">Section 7.3</a>).1212 it (for an example, see the notes on parameter handling for media types in <a href="#media.types" title="Media Types">Section 6.5</a>). 1217 1213 </p> 1218 1214 <p id="rfc.section.3.1.p.9">Authors of specifications defining new header fields are advised to consider documenting: </p> … … 1269 1265 <tr> 1270 1266 <td class="left">Accept</td> 1271 <td class="left"><a href="#header.accept" id="rfc.xref.header.accept.1" title="Accept">Section 1 1.11</a></td>1267 <td class="left"><a href="#header.accept" id="rfc.xref.header.accept.1" title="Accept">Section 10.11</a></td> 1272 1268 </tr> 1273 1269 <tr> 1274 1270 <td class="left">Accept-Charset</td> 1275 <td class="left"><a href="#header.accept-charset" id="rfc.xref.header.accept-charset.1" title="Accept-Charset">Section 1 1.12</a></td>1271 <td class="left"><a href="#header.accept-charset" id="rfc.xref.header.accept-charset.1" title="Accept-Charset">Section 10.12</a></td> 1276 1272 </tr> 1277 1273 <tr> 1278 1274 <td class="left">Accept-Encoding</td> 1279 <td class="left"><a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.1" title="Accept-Encoding">Section 1 1.13</a></td>1275 <td class="left"><a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.1" title="Accept-Encoding">Section 10.13</a></td> 1280 1276 </tr> 1281 1277 <tr> 1282 1278 <td class="left">Accept-Language</td> 1283 <td class="left"><a href="#header.accept-language" id="rfc.xref.header.accept-language.1" title="Accept-Language">Section 1 1.14</a></td>1279 <td class="left"><a href="#header.accept-language" id="rfc.xref.header.accept-language.1" title="Accept-Language">Section 10.14</a></td> 1284 1280 </tr> 1285 1281 <tr> … … 1289 1285 <tr> 1290 1286 <td class="left">Expect</td> 1291 <td class="left"><a href="#header.expect" id="rfc.xref.header.expect.1" title="Expect">Section 1 1.3</a></td>1287 <td class="left"><a href="#header.expect" id="rfc.xref.header.expect.1" title="Expect">Section 10.3</a></td> 1292 1288 </tr> 1293 1289 <tr> 1294 1290 <td class="left">From</td> 1295 <td class="left"><a href="#header.from" id="rfc.xref.header.from.1" title="From">Section 1 1.4</a></td>1291 <td class="left"><a href="#header.from" id="rfc.xref.header.from.1" title="From">Section 10.4</a></td> 1296 1292 </tr> 1297 1293 <tr> … … 1321 1317 <tr> 1322 1318 <td class="left">Max-Forwards</td> 1323 <td class="left"><a href="#header.max-forwards" id="rfc.xref.header.max-forwards.3" title="Max-Forwards">Section 1 1.6</a></td>1319 <td class="left"><a href="#header.max-forwards" id="rfc.xref.header.max-forwards.3" title="Max-Forwards">Section 10.6</a></td> 1324 1320 </tr> 1325 1321 <tr> … … 1333 1329 <tr> 1334 1330 <td class="left">Referer</td> 1335 <td class="left"><a href="#header.referer" id="rfc.xref.header.referer.1" title="Referer">Section 1 1.7</a></td>1331 <td class="left"><a href="#header.referer" id="rfc.xref.header.referer.1" title="Referer">Section 10.7</a></td> 1336 1332 </tr> 1337 1333 <tr> … … 1341 1337 <tr> 1342 1338 <td class="left">User-Agent</td> 1343 <td class="left"><a href="#header.user-agent" id="rfc.xref.header.user-agent.1" title="User-Agent">Section 1 1.10</a></td>1339 <td class="left"><a href="#header.user-agent" id="rfc.xref.header.user-agent.1" title="User-Agent">Section 10.10</a></td> 1344 1340 </tr> 1345 1341 </tbody> … … 1369 1365 <tr> 1370 1366 <td class="left">Allow</td> 1371 <td class="left"><a href="#header.allow" id="rfc.xref.header.allow.2" title="Allow">Section 1 1.1</a></td>1367 <td class="left"><a href="#header.allow" id="rfc.xref.header.allow.2" title="Allow">Section 10.1</a></td> 1372 1368 </tr> 1373 1369 <tr> 1374 1370 <td class="left">Date</td> 1375 <td class="left"><a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section 1 1.2</a></td>1371 <td class="left"><a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section 10.2</a></td> 1376 1372 </tr> 1377 1373 <tr> … … 1381 1377 <tr> 1382 1378 <td class="left">Location</td> 1383 <td class="left"><a href="#header.location" id="rfc.xref.header.location.2" title="Location">Section 1 1.5</a></td>1379 <td class="left"><a href="#header.location" id="rfc.xref.header.location.2" title="Location">Section 10.5</a></td> 1384 1380 </tr> 1385 1381 <tr> … … 1389 1385 <tr> 1390 1386 <td class="left">Retry-After</td> 1391 <td class="left"><a href="#header.retry-after" id="rfc.xref.header.retry-after.1" title="Retry-After">Section 1 1.8</a></td>1387 <td class="left"><a href="#header.retry-after" id="rfc.xref.header.retry-after.1" title="Retry-After">Section 10.8</a></td> 1392 1388 </tr> 1393 1389 <tr> 1394 1390 <td class="left">Server</td> 1395 <td class="left"><a href="#header.server" id="rfc.xref.header.server.1" title="Server">Section 1 1.9</a></td>1391 <td class="left"><a href="#header.server" id="rfc.xref.header.server.1" title="Server">Section 10.9</a></td> 1396 1392 </tr> 1397 1393 <tr> … … 1430 1426 </ul> 1431 1427 <p id="rfc.section.4.p.6">For most status codes the response can carry a payload, in which case a Content-Type header field indicates the payload's 1432 media type (<a href="#header.content-type" id="rfc.xref.header.content-type.2" title="Content-Type">Section 1 1.18</a>).1428 media type (<a href="#header.content-type" id="rfc.xref.header.content-type.2" title="Content-Type">Section 10.18</a>). 1433 1429 </p> 1434 1430 <h2 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1</a> <a id="overview.of.status.codes" href="#overview.of.status.codes">Overview of Status Codes</a></h2> … … 1809 1805 </li> 1810 1806 <li> 1811 <p>Redirection offering a choice of matching resources for use by agent-driven content negotiation (<a href="#agent-driven.negotiation" title="Agent-driven Negotiation">Section 10.2</a>). This is status code 300 (Multiple Choices).1807 <p>Redirection offering a choice of matching resources for use by agent-driven content negotiation (<a href="#agent-driven.negotiation" title="Agent-driven Negotiation">Section 9.2</a>). This is status code 300 (Multiple Choices). 1812 1808 </p> 1813 1809 </li> … … 1826 1822 </p> 1827 1823 </div> 1828 <p id="rfc.section.4.5.p.4">A Location header field on a 3xx response indicates that a client <em class="bcp14">MAY</em> automatically redirect to the URI provided; see <a href="#header.location" id="rfc.xref.header.location.3" title="Location">Section 1 1.5</a>.1824 <p id="rfc.section.4.5.p.4">A Location header field on a 3xx response indicates that a client <em class="bcp14">MAY</em> automatically redirect to the URI provided; see <a href="#header.location" id="rfc.xref.header.location.3" title="Location">Section 10.5</a>. 1829 1825 </p> 1830 1826 <p id="rfc.section.4.5.p.5">Note that for methods not known to be "safe", as defined in <a href="#safe.methods" title="Safe Methods">Section 2.1.1</a>, automatic redirection needs to done with care, since the redirect might change the conditions under which the request was … … 1841 1837 <h3 id="rfc.section.4.5.1"><a href="#rfc.section.4.5.1">4.5.1</a> <a id="status.300" href="#status.300">300 Multiple Choices</a></h3> 1842 1838 <p id="rfc.section.4.5.1.p.1">The target resource has more than one representation, each with its own specific location, and agent-driven negotiation information 1843 (<a href="#content.negotiation" title="Content Negotiation">Section 10</a>) is being provided so that the user (or user agent) can select a preferred representation by redirecting its request to that1839 (<a href="#content.negotiation" title="Content Negotiation">Section 9</a>) is being provided so that the user (or user agent) can select a preferred representation by redirecting its request to that 1844 1840 location. 1845 1841 </p> … … 2042 2038 <div id="rfc.iref.s.31"></div> 2043 2039 <h3 id="rfc.section.4.6.14"><a href="#rfc.section.4.6.14">4.6.14</a> <a id="status.417" href="#status.417">417 Expectation Failed</a></h3> 2044 <p id="rfc.section.4.6.14.p.1">The expectation given in an Expect header field (see <a href="#header.expect" id="rfc.xref.header.expect.2" title="Expect">Section 1 1.3</a>) could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could2040 <p id="rfc.section.4.6.14.p.1">The expectation given in an Expect header field (see <a href="#header.expect" id="rfc.xref.header.expect.2" title="Expect">Section 10.3</a>) could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could 2045 2041 not be met by the next-hop server. 2046 2042 </p> … … 2087 2083 <p id="rfc.section.4.7.4.p.1">The server is currently unable to handle the request due to a temporary overloading or maintenance of the server.</p> 2088 2084 <p id="rfc.section.4.7.4.p.2">The implication is that this is a temporary condition which will be alleviated after some delay. If known, the length of the 2089 delay <em class="bcp14">MAY</em> be indicated in a Retry-After header field (<a href="#header.retry-after" id="rfc.xref.header.retry-after.2" title="Retry-After">Section 1 1.8</a>). If no Retry-After is given, the client <em class="bcp14">SHOULD</em> handle the response as it would for a 500 response.2085 delay <em class="bcp14">MAY</em> be indicated in a Retry-After header field (<a href="#header.retry-after" id="rfc.xref.header.retry-after.2" title="Retry-After">Section 10.8</a>). If no Retry-After is given, the client <em class="bcp14">SHOULD</em> handle the response as it would for a 500 response. 2090 2086 </p> 2091 2087 <div class="note" id="rfc.section.4.7.4.p.3"> … … 2114 2110 <p id="rfc.section.5.p.1">Request and Response messages <em class="bcp14">MAY</em> transfer a representation if not otherwise restricted by the request method or response status code. A representation consists 2115 2111 of metadata (representation header fields) and data (representation body). When a complete or partial representation is enclosed 2116 in an HTTP message, it is referred to as the payload of the message. HTTP representations are defined in <a href="#payload" title="Payload">Section 8</a>.2112 in an HTTP message, it is referred to as the payload of the message. HTTP representations are defined in <a href="#payload" title="Payload">Section 7</a>. 2117 2113 </p> 2118 2114 <p id="rfc.section.5.p.2">A representation body is only present in a message when a message body is present, as described in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.36"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. The representation body is obtained from the message body by decoding any Transfer-Encoding that might have been applied … … 2243 2239 </pre><p id="rfc.section.6.2.p.5">Product tokens <em class="bcp14">SHOULD</em> be short and to the point. They <em class="bcp14">MUST NOT</em> be used for advertising or other non-essential information. Although any token octet <em class="bcp14">MAY</em> appear in a product-version, this token <em class="bcp14">SHOULD</em> only be used for a version identifier (i.e., successive versions of the same product <em class="bcp14">SHOULD</em> only differ in the product-version portion of the product value). 2244 2240 </p> 2245 <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a> <a id="protocol.parameters" href="#protocol.parameters">Protocol Parameters</a></h1> 2246 <h2 id="rfc.section.7.1"><a href="#rfc.section.7.1">7.1</a> <a id="character.sets" href="#character.sets">Character Encodings (charset)</a></h2> 2247 <p id="rfc.section.7.1.p.1">HTTP uses charset names to indicate the character encoding of a textual representation.</p> 2241 <h2 id="rfc.section.6.3"><a href="#rfc.section.6.3">6.3</a> <a id="character.sets" href="#character.sets">Character Encodings (charset)</a></h2> 2242 <p id="rfc.section.6.3.p.1">HTTP uses charset names to indicate the character encoding of a textual representation.</p> 2248 2243 <div id="rule.charset"> 2249 <p id="rfc.section. 7.1.p.2"> A character encoding is identified by a case-insensitive token. The complete set of tokens is defined by the IANA Character2244 <p id="rfc.section.6.3.p.2"> A character encoding is identified by a case-insensitive token. The complete set of tokens is defined by the IANA Character 2250 2245 Set registry (<<a href="http://www.iana.org/assignments/character-sets">http://www.iana.org/assignments/character-sets</a>>). 2251 2246 </p> 2252 2247 </div> 2253 2248 <div id="rfc.figure.u.18"></div><pre class="inline"><span id="rfc.iref.g.24"></span> <a href="#rule.charset" class="smpl">charset</a> = <a href="#core.rules" class="smpl">token</a> 2254 </pre><p id="rfc.section. 7.1.p.4">Although HTTP allows an arbitrary token to be used as a charset value, any token that has a predefined value within the IANA2249 </pre><p id="rfc.section.6.3.p.4">Although HTTP allows an arbitrary token to be used as a charset value, any token that has a predefined value within the IANA 2255 2250 Character Set registry <em class="bcp14">MUST</em> represent the character encoding defined by that registry. Applications <em class="bcp14">SHOULD</em> limit their use of character encodings to those defined within the IANA registry. 2256 2251 </p> 2257 <p id="rfc.section. 7.1.p.5">HTTP uses charset in two contexts: within an Accept-Charset request header field (in which the charset value is an unquoted2252 <p id="rfc.section.6.3.p.5">HTTP uses charset in two contexts: within an Accept-Charset request header field (in which the charset value is an unquoted 2258 2253 token) and as the value of a parameter in a Content-Type header field (within a request or response), in which case the parameter 2259 2254 value of the charset parameter can be quoted. 2260 2255 </p> 2261 <p id="rfc.section. 7.1.p.6">Implementors need to be aware of IETF character set requirements <a href="#RFC3629" id="rfc.xref.RFC3629.1"><cite title="UTF-8, a transformation format of ISO 10646">[RFC3629]</cite></a> <a href="#RFC2277" id="rfc.xref.RFC2277.1"><cite title="IETF Policy on Character Sets and Languages">[RFC2277]</cite></a>.2262 </p> 2263 <h2 id="rfc.section. 7.2"><a href="#rfc.section.7.2">7.2</a> <a id="content.codings" href="#content.codings">Content Codings</a></h2>2264 <p id="rfc.section. 7.2.p.1">Content coding values indicate an encoding transformation that has been or can be applied to a representation. Content codings2256 <p id="rfc.section.6.3.p.6">Implementors need to be aware of IETF character set requirements <a href="#RFC3629" id="rfc.xref.RFC3629.1"><cite title="UTF-8, a transformation format of ISO 10646">[RFC3629]</cite></a> <a href="#RFC2277" id="rfc.xref.RFC2277.1"><cite title="IETF Policy on Character Sets and Languages">[RFC2277]</cite></a>. 2257 </p> 2258 <h2 id="rfc.section.6.4"><a href="#rfc.section.6.4">6.4</a> <a id="content.codings" href="#content.codings">Content Codings</a></h2> 2259 <p id="rfc.section.6.4.p.1">Content coding values indicate an encoding transformation that has been or can be applied to a representation. Content codings 2265 2260 are primarily used to allow a representation to be compressed or otherwise usefully transformed without losing the identity 2266 2261 of its underlying media type and without loss of information. Frequently, the representation is stored in coded form, transmitted … … 2268 2263 </p> 2269 2264 <div id="rfc.figure.u.19"></div><pre class="inline"><span id="rfc.iref.g.25"></span> <a href="#content.codings" class="smpl">content-coding</a> = <a href="#core.rules" class="smpl">token</a> 2270 </pre><p id="rfc.section. 7.2.p.3">All content-coding values are case-insensitive. HTTP/1.1 uses content-coding values in the Accept-Encoding (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.2" title="Accept-Encoding">Section 11.13</a>) and Content-Encoding (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.1" title="Content-Encoding">Section 11.15</a>) header fields. Although the value describes the content-coding, what is more important is that it indicates what decoding2265 </pre><p id="rfc.section.6.4.p.3">All content-coding values are case-insensitive. HTTP/1.1 uses content-coding values in the Accept-Encoding (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.2" title="Accept-Encoding">Section 10.13</a>) and Content-Encoding (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.1" title="Content-Encoding">Section 10.15</a>) header fields. Although the value describes the content-coding, what is more important is that it indicates what decoding 2271 2266 mechanism will be required to remove the encoding. 2272 2267 </p> 2273 <p id="rfc.section. 7.2.p.4">compress<span id="rfc.iref.c.3"></span><span id="rfc.iref.c.4"></span>2268 <p id="rfc.section.6.4.p.4">compress<span id="rfc.iref.c.3"></span><span id="rfc.iref.c.4"></span> 2274 2269 </p> 2275 2270 <ul class="empty"> … … 2277 2272 </li> 2278 2273 </ul> 2279 <p id="rfc.section. 7.2.p.5">deflate<span id="rfc.iref.d.2"></span><span id="rfc.iref.c.5"></span>2274 <p id="rfc.section.6.4.p.5">deflate<span id="rfc.iref.d.2"></span><span id="rfc.iref.c.5"></span> 2280 2275 </p> 2281 2276 <ul class="empty"> … … 2283 2278 </li> 2284 2279 </ul> 2285 <p id="rfc.section. 7.2.p.6">gzip<span id="rfc.iref.g.26"></span><span id="rfc.iref.c.6"></span>2280 <p id="rfc.section.6.4.p.6">gzip<span id="rfc.iref.g.26"></span><span id="rfc.iref.c.6"></span> 2286 2281 </p> 2287 2282 <ul class="empty"> … … 2289 2284 </li> 2290 2285 </ul> 2291 <h3 id="rfc.section. 7.2.1"><a href="#rfc.section.7.2.1">7.2.1</a> <a id="content.coding.registry" href="#content.coding.registry">Content Coding Registry</a></h3>2292 <p id="rfc.section. 7.2.1.p.1">The HTTP Content Coding Registry defines the name space for the content coding names.</p>2293 <p id="rfc.section. 7.2.1.p.2">Registrations <em class="bcp14">MUST</em> include the following fields:2286 <h3 id="rfc.section.6.4.1"><a href="#rfc.section.6.4.1">6.4.1</a> <a id="content.coding.registry" href="#content.coding.registry">Content Coding Registry</a></h3> 2287 <p id="rfc.section.6.4.1.p.1">The HTTP Content Coding Registry defines the name space for the content coding names.</p> 2288 <p id="rfc.section.6.4.1.p.2">Registrations <em class="bcp14">MUST</em> include the following fields: 2294 2289 </p> 2295 2290 <ul> … … 2298 2293 <li>Pointer to specification text</li> 2299 2294 </ul> 2300 <p id="rfc.section. 7.2.1.p.3">Names of content codings <em class="bcp14">MUST NOT</em> overlap with names of transfer codings (<a href="p1-messaging.html#transfer.codings" title="Transfer Codings">Section 4</a> of <a href="#Part1" id="rfc.xref.Part1.41"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>), unless the encoding transformation is identical (as is the case for the compression codings defined in <a href="p1-messaging.html#compression.codings" title="Compression Codings">Section 4.2</a> of <a href="#Part1" id="rfc.xref.Part1.42"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>).2301 </p> 2302 <p id="rfc.section. 7.2.1.p.4">Values to be added to this name space require IETF Review (see <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a> of <a href="#RFC5226" id="rfc.xref.RFC5226.3"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>), and <em class="bcp14">MUST</em> conform to the purpose of content coding defined in this section.2303 </p> 2304 <p id="rfc.section. 7.2.1.p.5">The registry itself is maintained at <<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>>.2305 </p> 2306 <h2 id="rfc.section. 7.3"><a href="#rfc.section.7.3">7.3</a> <a id="media.types" href="#media.types">Media Types</a></h2>2307 <p id="rfc.section. 7.3.p.1">HTTP uses Internet Media Types <a href="#RFC2046" id="rfc.xref.RFC2046.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> in the Content-Type (<a href="#header.content-type" id="rfc.xref.header.content-type.3" title="Content-Type">Section 11.18</a>) and Accept (<a href="#header.accept" id="rfc.xref.header.accept.2" title="Accept">Section 11.11</a>) header fields in order to provide open and extensible data typing and type negotiation.2295 <p id="rfc.section.6.4.1.p.3">Names of content codings <em class="bcp14">MUST NOT</em> overlap with names of transfer codings (<a href="p1-messaging.html#transfer.codings" title="Transfer Codings">Section 4</a> of <a href="#Part1" id="rfc.xref.Part1.41"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>), unless the encoding transformation is identical (as is the case for the compression codings defined in <a href="p1-messaging.html#compression.codings" title="Compression Codings">Section 4.2</a> of <a href="#Part1" id="rfc.xref.Part1.42"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>). 2296 </p> 2297 <p id="rfc.section.6.4.1.p.4">Values to be added to this name space require IETF Review (see <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a> of <a href="#RFC5226" id="rfc.xref.RFC5226.3"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>), and <em class="bcp14">MUST</em> conform to the purpose of content coding defined in this section. 2298 </p> 2299 <p id="rfc.section.6.4.1.p.5">The registry itself is maintained at <<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>>. 2300 </p> 2301 <h2 id="rfc.section.6.5"><a href="#rfc.section.6.5">6.5</a> <a id="media.types" href="#media.types">Media Types</a></h2> 2302 <p id="rfc.section.6.5.p.1">HTTP uses Internet Media Types <a href="#RFC2046" id="rfc.xref.RFC2046.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> in the Content-Type (<a href="#header.content-type" id="rfc.xref.header.content-type.3" title="Content-Type">Section 10.18</a>) and Accept (<a href="#header.accept" id="rfc.xref.header.accept.2" title="Accept">Section 10.11</a>) header fields in order to provide open and extensible data typing and type negotiation. 2308 2303 </p> 2309 2304 <div id="rfc.figure.u.20"></div><pre class="inline"><span id="rfc.iref.g.27"></span><span id="rfc.iref.g.28"></span><span id="rfc.iref.g.29"></span> <a href="#media.types" class="smpl">media-type</a> = <a href="#media.types" class="smpl">type</a> "/" <a href="#media.types" class="smpl">subtype</a> *( <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> ) … … 2311 2306 <a href="#media.types" class="smpl">subtype</a> = <a href="#core.rules" class="smpl">token</a> 2312 2307 </pre><div id="rule.parameter"> 2313 <p id="rfc.section. 7.3.p.3"> The type/subtype <em class="bcp14">MAY</em> be followed by parameters in the form of attribute/value pairs.2308 <p id="rfc.section.6.5.p.3"> The type/subtype <em class="bcp14">MAY</em> be followed by parameters in the form of attribute/value pairs. 2314 2309 </p> 2315 2310 </div> … … 2317 2312 <a href="#rule.parameter" class="smpl">attribute</a> = <a href="#core.rules" class="smpl">token</a> 2318 2313 <a href="#rule.parameter" class="smpl">value</a> = word 2319 </pre><p id="rfc.section. 7.3.p.5">The type, subtype, and parameter attribute names are case-insensitive. Parameter values might or might not be case-sensitive,2314 </pre><p id="rfc.section.6.5.p.5">The type, subtype, and parameter attribute names are case-insensitive. Parameter values might or might not be case-sensitive, 2320 2315 depending on the semantics of the parameter name. The presence or absence of a parameter might be significant to the processing 2321 2316 of a media-type, depending on its definition within the media type registry. 2322 2317 </p> 2323 <p id="rfc.section. 7.3.p.6">A parameter value that matches the <a href="#core.rules" class="smpl">token</a> production can be transmitted as either a token or within a quoted-string. The quoted and unquoted values are equivalent.2324 </p> 2325 <p id="rfc.section. 7.3.p.7">Note that some older HTTP applications do not recognize media type parameters. When sending data to older HTTP applications,2318 <p id="rfc.section.6.5.p.6">A parameter value that matches the <a href="#core.rules" class="smpl">token</a> production can be transmitted as either a token or within a quoted-string. The quoted and unquoted values are equivalent. 2319 </p> 2320 <p id="rfc.section.6.5.p.7">Note that some older HTTP applications do not recognize media type parameters. When sending data to older HTTP applications, 2326 2321 implementations <em class="bcp14">SHOULD</em> only use media type parameters when they are required by that type/subtype definition. 2327 2322 </p> 2328 <p id="rfc.section. 7.3.p.8">Media-type values are registered with the Internet Assigned Number Authority (IANA). The media type registration process is2323 <p id="rfc.section.6.5.p.8">Media-type values are registered with the Internet Assigned Number Authority (IANA). The media type registration process is 2329 2324 outlined in <a href="#RFC4288" id="rfc.xref.RFC4288.1"><cite title="Media Type Specifications and Registration Procedures">[RFC4288]</cite></a>. Use of non-registered media types is discouraged. 2330 2325 </p> 2331 <h3 id="rfc.section. 7.3.1"><a href="#rfc.section.7.3.1">7.3.1</a> <a id="canonicalization.and.text.defaults" href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></h3>2332 <p id="rfc.section. 7.3.1.p.1">Internet media types are registered with a canonical form. A representation transferred via HTTP messages <em class="bcp14">MUST</em> be in the appropriate canonical form prior to its transmission except for "text" types, as defined in the next paragraph.2333 </p> 2334 <p id="rfc.section. 7.3.1.p.2">When in canonical form, media subtypes of the "text" type use CRLF as the text line break. HTTP relaxes this requirement and2326 <h3 id="rfc.section.6.5.1"><a href="#rfc.section.6.5.1">6.5.1</a> <a id="canonicalization.and.text.defaults" href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></h3> 2327 <p id="rfc.section.6.5.1.p.1">Internet media types are registered with a canonical form. A representation transferred via HTTP messages <em class="bcp14">MUST</em> be in the appropriate canonical form prior to its transmission except for "text" types, as defined in the next paragraph. 2328 </p> 2329 <p id="rfc.section.6.5.1.p.2">When in canonical form, media subtypes of the "text" type use CRLF as the text line break. HTTP relaxes this requirement and 2335 2330 allows the transport of text media with plain CR or LF alone representing a line break when it is done consistently for an 2336 2331 entire representation. HTTP applications <em class="bcp14">MUST</em> accept CRLF, bare CR, and bare LF as indicating a line break in text media received via HTTP. In addition, if the text is … … 2340 2335 body; a bare CR or LF <em class="bcp14">MUST NOT</em> be substituted for CRLF within any of the HTTP control structures (such as header fields and multipart boundaries). 2341 2336 </p> 2342 <p id="rfc.section. 7.3.1.p.3">If a representation is encoded with a content-coding, the underlying data <em class="bcp14">MUST</em> be in a form defined above prior to being encoded.2343 </p> 2344 <h3 id="rfc.section. 7.3.2"><a href="#rfc.section.7.3.2">7.3.2</a> <a id="multipart.types" href="#multipart.types">Multipart Types</a></h3>2345 <p id="rfc.section. 7.3.2.p.1">MIME provides for a number of "multipart" types — encapsulations of one or more representations within a single message body.2337 <p id="rfc.section.6.5.1.p.3">If a representation is encoded with a content-coding, the underlying data <em class="bcp14">MUST</em> be in a form defined above prior to being encoded. 2338 </p> 2339 <h3 id="rfc.section.6.5.2"><a href="#rfc.section.6.5.2">6.5.2</a> <a id="multipart.types" href="#multipart.types">Multipart Types</a></h3> 2340 <p id="rfc.section.6.5.2.p.1">MIME provides for a number of "multipart" types — encapsulations of one or more representations within a single message body. 2346 2341 All multipart types share a common syntax, as defined in <a href="http://tools.ietf.org/html/rfc2046#section-5.1.1">Section 5.1.1</a> of <a href="#RFC2046" id="rfc.xref.RFC2046.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, and <em class="bcp14">MUST</em> include a boundary parameter as part of the media type value. The message body is itself a protocol element and <em class="bcp14">MUST</em> therefore use only CRLF to represent line breaks between body-parts. 2347 2342 </p> 2348 <p id="rfc.section. 7.3.2.p.2">In general, HTTP treats a multipart message body no differently than any other media type: strictly as payload. HTTP does2343 <p id="rfc.section.6.5.2.p.2">In general, HTTP treats a multipart message body no differently than any other media type: strictly as payload. HTTP does 2349 2344 not use the multipart boundary as an indicator of message body length. In all other respects, an HTTP user agent <em class="bcp14">SHOULD</em> follow the same or similar behavior as a MIME user agent would upon receipt of a multipart type. The MIME header fields within 2350 2345 each body-part of a multipart message body do not have any significance to HTTP beyond that defined by their MIME semantics. 2351 2346 </p> 2352 <p id="rfc.section. 7.3.2.p.3">If an application receives an unrecognized multipart subtype, the application <em class="bcp14">MUST</em> treat it as being equivalent to "multipart/mixed".2353 </p> 2354 <div class="note" id="rfc.section. 7.3.2.p.4">2347 <p id="rfc.section.6.5.2.p.3">If an application receives an unrecognized multipart subtype, the application <em class="bcp14">MUST</em> treat it as being equivalent to "multipart/mixed". 2348 </p> 2349 <div class="note" id="rfc.section.6.5.2.p.4"> 2355 2350 <p> <b>Note:</b> The "multipart/form-data" type has been specifically defined for carrying form data suitable for processing via the POST request 2356 2351 method, as described in <a href="#RFC2388" id="rfc.xref.RFC2388.1"><cite title="Returning Values from Forms: multipart/form-data">[RFC2388]</cite></a>. 2357 2352 </p> 2358 2353 </div> 2359 <h2 id="rfc.section. 7.4"><a href="#rfc.section.7.4">7.4</a> <a id="language.tags" href="#language.tags">Language Tags</a></h2>2360 <p id="rfc.section. 7.4.p.1">A language tag, as defined in <a href="#RFC5646" id="rfc.xref.RFC5646.1"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, identifies a natural language spoken, written, or otherwise conveyed by human beings for communication of information to2354 <h2 id="rfc.section.6.6"><a href="#rfc.section.6.6">6.6</a> <a id="language.tags" href="#language.tags">Language Tags</a></h2> 2355 <p id="rfc.section.6.6.p.1">A language tag, as defined in <a href="#RFC5646" id="rfc.xref.RFC5646.1"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, identifies a natural language spoken, written, or otherwise conveyed by human beings for communication of information to 2361 2356 other human beings. Computer languages are explicitly excluded. HTTP uses language tags within the Accept-Language and Content-Language 2362 2357 fields. 2363 2358 </p> 2364 <p id="rfc.section. 7.4.p.2">In summary, a language tag is composed of one or more parts: A primary language subtag followed by a possibly empty series2359 <p id="rfc.section.6.6.p.2">In summary, a language tag is composed of one or more parts: A primary language subtag followed by a possibly empty series 2365 2360 of subtags: 2366 2361 </p> 2367 2362 <div id="rfc.figure.u.22"></div><pre class="inline"><span id="rfc.iref.g.33"></span> <a href="#language.tags" class="smpl">language-tag</a> = <Language-Tag, defined in <a href="#RFC5646" id="rfc.xref.RFC5646.2"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, <a href="http://tools.ietf.org/html/rfc5646#section-2.1">Section 2.1</a>> 2368 </pre><p id="rfc.section. 7.4.p.4">White space is not allowed within the tag and all tags are case-insensitive. The name space of language subtags is administered2363 </pre><p id="rfc.section.6.6.p.4">White space is not allowed within the tag and all tags are case-insensitive. The name space of language subtags is administered 2369 2364 by the IANA (see <<a href="http://www.iana.org/assignments/language-subtag-registry">http://www.iana.org/assignments/language-subtag-registry</a>>). 2370 2365 </p> 2371 2366 <div id="rfc.figure.u.23"></div> 2372 2367 <p>Example tags include:</p> <pre class="text"> en, en-US, es-419, az-Arab, x-pig-latin, man-Nkoo-GN 2373 </pre> <p id="rfc.section. 7.4.p.6">See <a href="#RFC5646" id="rfc.xref.RFC5646.3"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a> for further information.2374 </p> 2375 <h1 id="rfc.section. 8"><a href="#rfc.section.8">8.</a> <a id="payload" href="#payload">Payload</a></h1>2376 <p id="rfc.section. 8.p.1">HTTP messages <em class="bcp14">MAY</em> transfer a payload if not otherwise restricted by the request method or response status code. The payload consists of metadata,2368 </pre> <p id="rfc.section.6.6.p.6">See <a href="#RFC5646" id="rfc.xref.RFC5646.3"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a> for further information. 2369 </p> 2370 <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a> <a id="payload" href="#payload">Payload</a></h1> 2371 <p id="rfc.section.7.p.1">HTTP messages <em class="bcp14">MAY</em> transfer a payload if not otherwise restricted by the request method or response status code. The payload consists of metadata, 2377 2372 in the form of header fields, and data, in the form of the sequence of octets in the message body after any transfer-coding 2378 2373 has been decoded. 2379 2374 </p> 2380 2375 <div id="rfc.iref.p.3"></div> 2381 <p id="rfc.section. 8.p.2">A "<dfn>payload</dfn>" in HTTP is always a partial or complete representation of some resource. We use separate terms for payload and representation2376 <p id="rfc.section.7.p.2">A "<dfn>payload</dfn>" in HTTP is always a partial or complete representation of some resource. We use separate terms for payload and representation 2382 2377 because some messages contain only the associated representation's header fields (e.g., responses to HEAD) or only some part(s) 2383 2378 of the representation (e.g., the 206 status code). 2384 2379 </p> 2385 <h2 id="rfc.section. 8.1"><a href="#rfc.section.8.1">8.1</a> <a id="payload.header.fields" href="#payload.header.fields">Payload Header Fields</a></h2>2386 <p id="rfc.section. 8.1.p.1">HTTP header fields that specifically define the payload, rather than the associated representation, are referred to as "payload2380 <h2 id="rfc.section.7.1"><a href="#rfc.section.7.1">7.1</a> <a id="payload.header.fields" href="#payload.header.fields">Payload Header Fields</a></h2> 2381 <p id="rfc.section.7.1.p.1">HTTP header fields that specifically define the payload, rather than the associated representation, are referred to as "payload 2387 2382 header fields". The following payload header fields are defined by HTTP/1.1: 2388 2383 </p> … … 2407 2402 </table> 2408 2403 </div> 2409 <h2 id="rfc.section. 8.2"><a href="#rfc.section.8.2">8.2</a> <a id="payload.body" href="#payload.body">Payload Body</a></h2>2410 <p id="rfc.section. 8.2.p.1">A payload body is only present in a message when a message body is present, as described in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.44"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. The payload body is obtained from the message body by decoding any Transfer-Encoding that might have been applied to ensure2404 <h2 id="rfc.section.7.2"><a href="#rfc.section.7.2">7.2</a> <a id="payload.body" href="#payload.body">Payload Body</a></h2> 2405 <p id="rfc.section.7.2.p.1">A payload body is only present in a message when a message body is present, as described in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.44"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. The payload body is obtained from the message body by decoding any Transfer-Encoding that might have been applied to ensure 2411 2406 safe and proper transfer of the message. 2412 2407 </p> 2413 2408 <div id="rfc.iref.r.1"></div> 2414 <h1 id="rfc.section. 9"><a href="#rfc.section.9">9.</a> <a id="representation-TODO" href="#representation-TODO">Representation</a></h1>2415 <p id="rfc.section. 9.p.1">A "<dfn>representation</dfn>" is information in a format that can be readily communicated from one party to another. A resource representation is information2409 <h1 id="rfc.section.8"><a href="#rfc.section.8">8.</a> <a id="representation-TODO" href="#representation-TODO">Representation</a></h1> 2410 <p id="rfc.section.8.p.1">A "<dfn>representation</dfn>" is information in a format that can be readily communicated from one party to another. A resource representation is information 2416 2411 that reflects the state of that resource, as observed at some point in the past (e.g., in a response to GET) or to be desired 2417 2412 at some point in the future (e.g., in a PUT request). 2418 2413 </p> 2419 <p id="rfc.section. 9.p.2">Most, but not all, representations transferred via HTTP are intended to be a representation of the target resource (the resource2414 <p id="rfc.section.8.p.2">Most, but not all, representations transferred via HTTP are intended to be a representation of the target resource (the resource 2420 2415 identified by the effective request URI). The precise semantics of a representation are determined by the type of message 2421 2416 (request or response), the request method, the response status code, and the representation metadata. For example, the above … … 2426 2421 next steps are suggested for resolving it. 2427 2422 </p> 2428 <h2 id="rfc.section. 9.1"><a href="#rfc.section.9.1">9.1</a> <a id="representation.header.fields" href="#representation.header.fields">Representation Header Fields</a></h2>2429 <p id="rfc.section. 9.1.p.1">Representation header fields define metadata about the representation data enclosed in the message body or, if no message2423 <h2 id="rfc.section.8.1"><a href="#rfc.section.8.1">8.1</a> <a id="representation.header.fields" href="#representation.header.fields">Representation Header Fields</a></h2> 2424 <p id="rfc.section.8.1.p.1">Representation header fields define metadata about the representation data enclosed in the message body or, if no message 2430 2425 body is present, about the representation that would have been transferred in a 200 response to a simultaneous GET request 2431 2426 with the same effective request URI. 2432 2427 </p> 2433 <p id="rfc.section. 9.1.p.2">The following header fields are defined as representation metadata:</p>2428 <p id="rfc.section.8.1.p.2">The following header fields are defined as representation metadata:</p> 2434 2429 <div id="rfc.table.u.5"> 2435 2430 <table class="tt full left" cellpadding="3" cellspacing="0"> … … 2443 2438 <tr> 2444 2439 <td class="left">Content-Encoding</td> 2445 <td class="left"><a href="#header.content-encoding" id="rfc.xref.header.content-encoding.2" title="Content-Encoding">Section 1 1.15</a></td>2440 <td class="left"><a href="#header.content-encoding" id="rfc.xref.header.content-encoding.2" title="Content-Encoding">Section 10.15</a></td> 2446 2441 </tr> 2447 2442 <tr> 2448 2443 <td class="left">Content-Language</td> 2449 <td class="left"><a href="#header.content-language" id="rfc.xref.header.content-language.1" title="Content-Language">Section 1 1.16</a></td>2444 <td class="left"><a href="#header.content-language" id="rfc.xref.header.content-language.1" title="Content-Language">Section 10.16</a></td> 2450 2445 </tr> 2451 2446 <tr> 2452 2447 <td class="left">Content-Location</td> 2453 <td class="left"><a href="#header.content-location" id="rfc.xref.header.content-location.2" title="Content-Location">Section 1 1.17</a></td>2448 <td class="left"><a href="#header.content-location" id="rfc.xref.header.content-location.2" title="Content-Location">Section 10.17</a></td> 2454 2449 </tr> 2455 2450 <tr> 2456 2451 <td class="left">Content-Type</td> 2457 <td class="left"><a href="#header.content-type" id="rfc.xref.header.content-type.4" title="Content-Type">Section 1 1.18</a></td>2452 <td class="left"><a href="#header.content-type" id="rfc.xref.header.content-type.4" title="Content-Type">Section 10.18</a></td> 2458 2453 </tr> 2459 2454 <tr> … … 2464 2459 </table> 2465 2460 </div> 2466 <p id="rfc.section. 9.1.p.3">Additional header fields define metadata about the selected representation, which might differ from the representation included2461 <p id="rfc.section.8.1.p.3">Additional header fields define metadata about the selected representation, which might differ from the representation included 2467 2462 in the message for responses to some state-changing methods. The following header fields are defined as selected representation 2468 2463 metadata: … … 2488 2483 </table> 2489 2484 </div> 2490 <h2 id="rfc.section. 9.2"><a href="#rfc.section.9.2">9.2</a> <a id="representation.data" href="#representation.data">Representation Data</a></h2>2491 <p id="rfc.section. 9.2.p.1">The representation body associated with an HTTP message is either provided as the payload body of the message or referred2485 <h2 id="rfc.section.8.2"><a href="#rfc.section.8.2">8.2</a> <a id="representation.data" href="#representation.data">Representation Data</a></h2> 2486 <p id="rfc.section.8.2.p.1">The representation body associated with an HTTP message is either provided as the payload body of the message or referred 2492 2487 to by the message semantics and the effective request URI. The representation data is in a format and encoding defined by 2493 2488 the representation metadata header fields. 2494 2489 </p> 2495 <p id="rfc.section. 9.2.p.2">The data type of the representation data is determined via the header fields Content-Type and Content-Encoding. These define2490 <p id="rfc.section.8.2.p.2">The data type of the representation data is determined via the header fields Content-Type and Content-Encoding. These define 2496 2491 a two-layer, ordered encoding model: 2497 2492 </p> 2498 2493 <div id="rfc.figure.u.24"></div><pre class="text"> representation-data := Content-Encoding( Content-Type( bits ) ) 2499 </pre><p id="rfc.section. 9.2.p.4">Content-Type specifies the media type of the underlying data, which defines both the data format and how that data <em class="bcp14">SHOULD</em> be processed by the recipient (within the scope of the request method semantics). Any HTTP/1.1 message containing a payload2494 </pre><p id="rfc.section.8.2.p.4">Content-Type specifies the media type of the underlying data, which defines both the data format and how that data <em class="bcp14">SHOULD</em> be processed by the recipient (within the scope of the request method semantics). Any HTTP/1.1 message containing a payload 2500 2495 body <em class="bcp14">SHOULD</em> include a Content-Type header field defining the media type of the associated representation unless that metadata is unknown 2501 2496 to the sender. If the Content-Type header field is not present, it indicates that the sender does not know the media type 2502 2497 of the representation; recipients <em class="bcp14">MAY</em> either assume that the media type is "application/octet-stream" (<a href="#RFC2046" id="rfc.xref.RFC2046.3"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, <a href="http://tools.ietf.org/html/rfc2046#section-4.5.1">Section 4.5.1</a>) or examine the content to determine its type. 2503 2498 </p> 2504 <p id="rfc.section. 9.2.p.5">In practice, resource owners do not always properly configure their origin server to provide the correct Content-Type for2499 <p id="rfc.section.8.2.p.5">In practice, resource owners do not always properly configure their origin server to provide the correct Content-Type for 2505 2500 a given representation, with the result that some clients will examine a response body's content and override the specified 2506 2501 type. Clients that do so risk drawing incorrect conclusions, which might expose additional security risks (e.g., "privilege … … 2509 2504 such "content sniffing" when it is used. 2510 2505 </p> 2511 <p id="rfc.section. 9.2.p.6">Content-Encoding is used to indicate any additional content codings applied to the data, usually for the purpose of data compression,2506 <p id="rfc.section.8.2.p.6">Content-Encoding is used to indicate any additional content codings applied to the data, usually for the purpose of data compression, 2512 2507 that are a property of the representation. If Content-Encoding is not present, then there is no additional encoding beyond 2513 2508 that defined by the Content-Type. 2514 2509 </p> 2515 <h1 id="rfc.section. 10"><a href="#rfc.section.10">10.</a> <a id="content.negotiation" href="#content.negotiation">Content Negotiation</a></h1>2516 <p id="rfc.section. 10.p.1">HTTP responses include a representation which contains information for interpretation, whether by a human user or for further2510 <h1 id="rfc.section.9"><a href="#rfc.section.9">9.</a> <a id="content.negotiation" href="#content.negotiation">Content Negotiation</a></h1> 2511 <p id="rfc.section.9.p.1">HTTP responses include a representation which contains information for interpretation, whether by a human user or for further 2517 2512 processing. Often, the server has different ways of representing the same information; for example, in different formats, 2518 2513 languages, or using different character encodings. 2519 2514 </p> 2520 <p id="rfc.section. 10.p.2">HTTP clients and their users might have different or variable capabilities, characteristics or preferences which would influence2515 <p id="rfc.section.9.p.2">HTTP clients and their users might have different or variable capabilities, characteristics or preferences which would influence 2521 2516 which representation, among those available from the server, would be best for the server to deliver. For this reason, HTTP 2522 2517 provides mechanisms for "content negotiation" — a process of allowing selection of a representation of a given resource, when 2523 2518 more than one is available. 2524 2519 </p> 2525 <p id="rfc.section. 10.p.3">This specification defines two patterns of content negotiation; "server-driven", where the server selects the representation2520 <p id="rfc.section.9.p.3">This specification defines two patterns of content negotiation; "server-driven", where the server selects the representation 2526 2521 based upon the client's stated preferences, and "agent-driven" negotiation, where the server provides a list of representations 2527 2522 for the client to choose from, based upon their metadata. In addition, there are other patterns: some applications use an … … 2529 2524 parameters, selects additional resources to invoke. "Transparent Content Negotiation" (<a href="#RFC2295" id="rfc.xref.RFC2295.1"><cite title="Transparent Content Negotiation in HTTP">[RFC2295]</cite></a>) has also been proposed. 2530 2525 </p> 2531 <p id="rfc.section. 10.p.4">These patterns are all widely used, and have trade-offs in applicability and practicality. In particular, when the number2526 <p id="rfc.section.9.p.4">These patterns are all widely used, and have trade-offs in applicability and practicality. In particular, when the number 2532 2527 of preferences or capabilities to be expressed by a client are large (such as when many different formats are supported by 2533 2528 a user-agent), server-driven negotiation becomes unwieldy, and might not be appropriate. Conversely, when the number of representations 2534 2529 to choose from is very large, agent-driven negotiation might not be appropriate. 2535 2530 </p> 2536 <p id="rfc.section. 10.p.5">Note that in all cases, the supplier of representations has the responsibility for determining which representations might2531 <p id="rfc.section.9.p.5">Note that in all cases, the supplier of representations has the responsibility for determining which representations might 2537 2532 be considered to be the "same information". 2538 2533 </p> 2539 <h2 id="rfc.section. 10.1"><a href="#rfc.section.10.1">10.1</a> <a id="server-driven.negotiation" href="#server-driven.negotiation">Server-driven Negotiation</a></h2>2540 <p id="rfc.section. 10.1.p.1">If the selection of the best representation for a response is made by an algorithm located at the server, it is called server-driven2534 <h2 id="rfc.section.9.1"><a href="#rfc.section.9.1">9.1</a> <a id="server-driven.negotiation" href="#server-driven.negotiation">Server-driven Negotiation</a></h2> 2535 <p id="rfc.section.9.1.p.1">If the selection of the best representation for a response is made by an algorithm located at the server, it is called server-driven 2541 2536 negotiation. Selection is based on the available representations of the response (the dimensions over which it can vary; e.g., 2542 2537 language, content-coding, etc.) and the contents of particular header fields in the request message or on other information 2543 2538 pertaining to the request (such as the network address of the client). 2544 2539 </p> 2545 <p id="rfc.section. 10.1.p.2">Server-driven negotiation is advantageous when the algorithm for selecting from among the available representations is difficult2540 <p id="rfc.section.9.1.p.2">Server-driven negotiation is advantageous when the algorithm for selecting from among the available representations is difficult 2546 2541 to describe to the user agent, or when the server desires to send its "best guess" to the client along with the first response 2547 2542 (hoping to avoid the round-trip delay of a subsequent request if the "best guess" is good enough for the user). In order to 2548 2543 improve the server's guess, the user agent <em class="bcp14">MAY</em> include request header fields (Accept, Accept-Language, Accept-Encoding, etc.) which describe its preferences for such a response. 2549 2544 </p> 2550 <p id="rfc.section. 10.1.p.3">Server-driven negotiation has disadvantages: </p>2545 <p id="rfc.section.9.1.p.3">Server-driven negotiation has disadvantages: </p> 2551 2546 <ol> 2552 2547 <li>It is impossible for the server to accurately determine what might be "best" for any given user, since that would require … … 2560 2555 <li>It might limit a public cache's ability to use the same response for multiple user's requests.</li> 2561 2556 </ol> 2562 <p id="rfc.section. 10.1.p.4">Server-driven negotiation allows the user agent to specify its preferences, but it cannot expect responses to always honor2557 <p id="rfc.section.9.1.p.4">Server-driven negotiation allows the user agent to specify its preferences, but it cannot expect responses to always honor 2563 2558 them. For example, the origin server might not implement server-driven negotiation, or it might decide that sending a response 2564 2559 that doesn't conform to them is better than sending a 406 (Not Acceptable) response. 2565 2560 </p> 2566 <p id="rfc.section. 10.1.p.5">Many of the mechanisms for expressing preferences use quality values to declare relative preference. See qvalue; for more2561 <p id="rfc.section.9.1.p.5">Many of the mechanisms for expressing preferences use quality values to declare relative preference. See qvalue; for more 2567 2562 information. 2568 2563 </p> 2569 <p id="rfc.section. 10.1.p.6">HTTP/1.1 includes the following header fields for enabling server-driven negotiation through description of user agent capabilities2570 and user preferences: Accept (<a href="#header.accept" id="rfc.xref.header.accept.3" title="Accept">Section 1 1.11</a>), Accept-Charset (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.2" title="Accept-Charset">Section 11.12</a>), Accept-Encoding (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.3" title="Accept-Encoding">Section 11.13</a>), Accept-Language (<a href="#header.accept-language" id="rfc.xref.header.accept-language.2" title="Accept-Language">Section 11.14</a>), and User-Agent (<a href="#header.user-agent" id="rfc.xref.header.user-agent.2" title="User-Agent">Section 11.10</a>). However, an origin server is not limited to these dimensions and <em class="bcp14">MAY</em> vary the response based on any aspect of the request, including aspects of the connection (e.g., IP address) or information2564 <p id="rfc.section.9.1.p.6">HTTP/1.1 includes the following header fields for enabling server-driven negotiation through description of user agent capabilities 2565 and user preferences: Accept (<a href="#header.accept" id="rfc.xref.header.accept.3" title="Accept">Section 10.11</a>), Accept-Charset (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.2" title="Accept-Charset">Section 10.12</a>), Accept-Encoding (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.3" title="Accept-Encoding">Section 10.13</a>), Accept-Language (<a href="#header.accept-language" id="rfc.xref.header.accept-language.2" title="Accept-Language">Section 10.14</a>), and User-Agent (<a href="#header.user-agent" id="rfc.xref.header.user-agent.2" title="User-Agent">Section 10.10</a>). However, an origin server is not limited to these dimensions and <em class="bcp14">MAY</em> vary the response based on any aspect of the request, including aspects of the connection (e.g., IP address) or information 2571 2566 within extension header fields not defined by this specification. 2572 2567 </p> 2573 <div class="note" id="rfc.section. 10.1.p.7">2568 <div class="note" id="rfc.section.9.1.p.7"> 2574 2569 <p> <b>Note:</b> In practice, User-Agent based negotiation is fragile, because new clients might not be recognized. 2575 2570 </p> 2576 2571 </div> 2577 <p id="rfc.section. 10.1.p.8">The Vary header field (<a href="p6-cache.html#header.vary" title="Vary">Section 3.5</a> of <a href="#Part6" id="rfc.xref.Part6.19"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) can be used to express the parameters the server uses to select a representation that is subject to server-driven negotiation.2578 </p> 2579 <h2 id="rfc.section. 10.2"><a href="#rfc.section.10.2">10.2</a> <a id="agent-driven.negotiation" href="#agent-driven.negotiation">Agent-driven Negotiation</a></h2>2580 <p id="rfc.section. 10.2.p.1">With agent-driven negotiation, selection of the best representation for a response is performed by the user agent after receiving2572 <p id="rfc.section.9.1.p.8">The Vary header field (<a href="p6-cache.html#header.vary" title="Vary">Section 3.5</a> of <a href="#Part6" id="rfc.xref.Part6.19"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) can be used to express the parameters the server uses to select a representation that is subject to server-driven negotiation. 2573 </p> 2574 <h2 id="rfc.section.9.2"><a href="#rfc.section.9.2">9.2</a> <a id="agent-driven.negotiation" href="#agent-driven.negotiation">Agent-driven Negotiation</a></h2> 2575 <p id="rfc.section.9.2.p.1">With agent-driven negotiation, selection of the best representation for a response is performed by the user agent after receiving 2581 2576 an initial response from the origin server. Selection is based on a list of the available representations of the response 2582 2577 included within the header fields or body of the initial response, with each representation identified by its own URI. Selection … … 2584 2579 user selecting from a generated (possibly hypertext) menu. 2585 2580 </p> 2586 <p id="rfc.section. 10.2.p.2">Agent-driven negotiation is advantageous when the response would vary over commonly-used dimensions (such as type, language,2581 <p id="rfc.section.9.2.p.2">Agent-driven negotiation is advantageous when the response would vary over commonly-used dimensions (such as type, language, 2587 2582 or encoding), when the origin server is unable to determine a user agent's capabilities from examining the request, and generally 2588 2583 when public caches are used to distribute server load and reduce network usage. 2589 2584 </p> 2590 <p id="rfc.section. 10.2.p.3">Agent-driven negotiation suffers from the disadvantage of needing a second request to obtain the best alternate representation.2585 <p id="rfc.section.9.2.p.3">Agent-driven negotiation suffers from the disadvantage of needing a second request to obtain the best alternate representation. 2591 2586 This second request is only efficient when caching is used. In addition, this specification does not define any mechanism 2592 2587 for supporting automatic selection, though it also does not prevent any such mechanism from being developed as an extension 2593 2588 and used within HTTP/1.1. 2594 2589 </p> 2595 <p id="rfc.section. 10.2.p.4">This specification defines the 300 (Multiple Choices) and 406 (Not Acceptable) status codes for enabling agent-driven negotiation2590 <p id="rfc.section.9.2.p.4">This specification defines the 300 (Multiple Choices) and 406 (Not Acceptable) status codes for enabling agent-driven negotiation 2596 2591 when the server is unwilling or unable to provide a varying response using server-driven negotiation. 2597 2592 </p> 2598 <h1 id="rfc.section.1 1"><a href="#rfc.section.11">11.</a> <a id="header.field.definitions" href="#header.field.definitions">Header Field Definitions</a></h1>2599 <p id="rfc.section.1 1.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to request and response semantics, and to2593 <h1 id="rfc.section.10"><a href="#rfc.section.10">10.</a> <a id="header.field.definitions" href="#header.field.definitions">Header Field Definitions</a></h1> 2594 <p id="rfc.section.10.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to request and response semantics, and to 2600 2595 the payload of messages. 2601 2596 </p> 2602 2597 <div id="rfc.iref.a.1"></div> 2603 2598 <div id="rfc.iref.h.2"></div> 2604 <h2 id="rfc.section.1 1.1"><a href="#rfc.section.11.1">11.1</a> <a id="header.allow" href="#header.allow">Allow</a></h2>2605 <p id="rfc.section.1 1.1.p.1">The "Allow" header field lists the set of methods advertised as supported by the target resource. The purpose of this field2599 <h2 id="rfc.section.10.1"><a href="#rfc.section.10.1">10.1</a> <a id="header.allow" href="#header.allow">Allow</a></h2> 2600 <p id="rfc.section.10.1.p.1">The "Allow" header field lists the set of methods advertised as supported by the target resource. The purpose of this field 2606 2601 is strictly to inform the recipient of valid request methods associated with the resource. 2607 2602 </p> 2608 2603 <div id="rfc.figure.u.25"></div><pre class="inline"><span id="rfc.iref.g.34"></span> <a href="#header.allow" class="smpl">Allow</a> = #<a href="#methods" class="smpl">method</a> 2609 </pre><p id="rfc.section.1 1.1.p.3">Example of use:</p>2604 </pre><p id="rfc.section.10.1.p.3">Example of use:</p> 2610 2605 <div id="rfc.figure.u.26"></div><pre class="text"> Allow: GET, HEAD, PUT 2611 </pre><p id="rfc.section.1 1.1.p.5">The actual set of allowed methods is defined by the origin server at the time of each request.</p>2612 <p id="rfc.section.1 1.1.p.6">A proxy <em class="bcp14">MUST NOT</em> modify the Allow header field — it does not need to understand all the methods specified in order to handle them according2606 </pre><p id="rfc.section.10.1.p.5">The actual set of allowed methods is defined by the origin server at the time of each request.</p> 2607 <p id="rfc.section.10.1.p.6">A proxy <em class="bcp14">MUST NOT</em> modify the Allow header field — it does not need to understand all the methods specified in order to handle them according 2613 2608 to the generic message handling rules. 2614 2609 </p> 2615 2610 <div id="rfc.iref.d.3"></div> 2616 2611 <div id="rfc.iref.h.3"></div> 2617 <h2 id="rfc.section.1 1.2"><a href="#rfc.section.11.2">11.2</a> <a id="header.date" href="#header.date">Date</a></h2>2618 <p id="rfc.section.1 1.2.p.1">The "Date" header field represents the date and time at which the message was originated, having the same semantics as the2612 <h2 id="rfc.section.10.2"><a href="#rfc.section.10.2">10.2</a> <a id="header.date" href="#header.date">Date</a></h2> 2613 <p id="rfc.section.10.2.p.1">The "Date" header field represents the date and time at which the message was originated, having the same semantics as the 2619 2614 Origination Date Field (orig-date) defined in <a href="http://tools.ietf.org/html/rfc5322#section-3.6.1">Section 3.6.1</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.2"><cite title="Internet Message Format">[RFC5322]</cite></a>. The field value is an HTTP-date, as defined in <a href="#http.date" title="Date/Time Formats">Section 6.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format. 2620 2615 </p> 2621 2616 <div id="rfc.figure.u.27"></div><pre class="inline"><span id="rfc.iref.g.35"></span> <a href="#header.date" class="smpl">Date</a> = <a href="#http.date" class="smpl">HTTP-date</a> 2622 </pre><p id="rfc.section.1 1.2.p.3">An example is</p>2617 </pre><p id="rfc.section.10.2.p.3">An example is</p> 2623 2618 <div id="rfc.figure.u.28"></div><pre class="text"> Date: Tue, 15 Nov 1994 08:12:31 GMT 2624 </pre><p id="rfc.section.1 1.2.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases:2619 </pre><p id="rfc.section.10.2.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases: 2625 2620 </p> 2626 2621 <ol> … … 2633 2628 </li> 2634 2629 </ol> 2635 <p id="rfc.section.1 1.2.p.6">A received message that does not have a Date header field <em class="bcp14">MUST</em> be assigned one by the recipient if the message will be cached by that recipient.2636 </p> 2637 <p id="rfc.section.1 1.2.p.7">Clients can use the Date header field as well; in order to keep request messages small, they are advised not to include it2630 <p id="rfc.section.10.2.p.6">A received message that does not have a Date header field <em class="bcp14">MUST</em> be assigned one by the recipient if the message will be cached by that recipient. 2631 </p> 2632 <p id="rfc.section.10.2.p.7">Clients can use the Date header field as well; in order to keep request messages small, they are advised not to include it 2638 2633 when it doesn't convey any useful information (as is usually the case for requests that do not contain a payload). 2639 2634 </p> 2640 <p id="rfc.section.1 1.2.p.8">The HTTP-date sent in a Date header field <em class="bcp14">SHOULD NOT</em> represent a date and time subsequent to the generation of the message. It <em class="bcp14">SHOULD</em> represent the best available approximation of the date and time of message generation, unless the implementation has no means2635 <p id="rfc.section.10.2.p.8">The HTTP-date sent in a Date header field <em class="bcp14">SHOULD NOT</em> represent a date and time subsequent to the generation of the message. It <em class="bcp14">SHOULD</em> represent the best available approximation of the date and time of message generation, unless the implementation has no means 2641 2636 of generating a reasonably accurate date and time. In theory, the date ought to represent the moment just before the payload 2642 2637 is generated. In practice, the date can be generated at any time during the message origination without affecting its semantic … … 2645 2640 <div id="rfc.iref.e.1"></div> 2646 2641 <div id="rfc.iref.h.4"></div> 2647 <h2 id="rfc.section.1 1.3"><a href="#rfc.section.11.3">11.3</a> <a id="header.expect" href="#header.expect">Expect</a></h2>2648 <p id="rfc.section.1 1.3.p.1">The "Expect" header field is used to indicate that particular server behaviors are required by the client.</p>2642 <h2 id="rfc.section.10.3"><a href="#rfc.section.10.3">10.3</a> <a id="header.expect" href="#header.expect">Expect</a></h2> 2643 <p id="rfc.section.10.3.p.1">The "Expect" header field is used to indicate that particular server behaviors are required by the client.</p> 2649 2644 <div id="rfc.figure.u.29"></div><pre class="inline"><span id="rfc.iref.g.36"></span><span id="rfc.iref.g.37"></span><span id="rfc.iref.g.38"></span><span id="rfc.iref.g.39"></span><span id="rfc.iref.g.40"></span> <a href="#header.expect" class="smpl">Expect</a> = 1#<a href="#header.expect" class="smpl">expectation</a> 2650 2645 … … 2655 2650 <a href="#header.expect" class="smpl">expect-name</a> = <a href="#core.rules" class="smpl">token</a> 2656 2651 <a href="#header.expect" class="smpl">expect-value</a> = <a href="#core.rules" class="smpl">token</a> / <a href="#core.rules" class="smpl">quoted-string</a> 2657 </pre><p id="rfc.section.1 1.3.p.3">If all received Expect header field(s) are syntactically valid but contain an expectation that the recipient does not understand2652 </pre><p id="rfc.section.10.3.p.3">If all received Expect header field(s) are syntactically valid but contain an expectation that the recipient does not understand 2658 2653 or cannot comply with, the recipient <em class="bcp14">MUST</em> respond with a 417 (Expectation Failed) status code. A recipient of a syntactically invalid Expectation header field <em class="bcp14">MUST</em> respond with a 4xx status code other than 417. 2659 2654 </p> 2660 <p id="rfc.section.1 1.3.p.4">The only expectation defined by this specification is:</p>2661 <p id="rfc.section.1 1.3.p.5"><span id="rfc.iref.108"></span><span id="rfc.iref.e.2"></span> 100-continue2655 <p id="rfc.section.10.3.p.4">The only expectation defined by this specification is:</p> 2656 <p id="rfc.section.10.3.p.5"><span id="rfc.iref.108"></span><span id="rfc.iref.e.2"></span> 100-continue 2662 2657 </p> 2663 2658 <ul class="empty"> … … 2665 2660 </li> 2666 2661 </ul> 2667 <p id="rfc.section.1 1.3.p.6">Comparison is case-insensitive for names (expect-name), and case-sensitive for values (expect-value).</p>2668 <p id="rfc.section.1 1.3.p.7">The Expect mechanism is hop-by-hop: the above requirements apply to any server, including proxies. However, the Expect header2662 <p id="rfc.section.10.3.p.6">Comparison is case-insensitive for names (expect-name), and case-sensitive for values (expect-value).</p> 2663 <p id="rfc.section.10.3.p.7">The Expect mechanism is hop-by-hop: the above requirements apply to any server, including proxies. However, the Expect header 2669 2664 field itself is end-to-end; it <em class="bcp14">MUST</em> be forwarded if the request is forwarded. 2670 2665 </p> 2671 <p id="rfc.section.1 1.3.p.8">Many older HTTP/1.0 and HTTP/1.1 applications do not understand the Expect header field.</p>2666 <p id="rfc.section.10.3.p.8">Many older HTTP/1.0 and HTTP/1.1 applications do not understand the Expect header field.</p> 2672 2667 <div id="rfc.iref.f.1"></div> 2673 2668 <div id="rfc.iref.h.5"></div> 2674 <h2 id="rfc.section.1 1.4"><a href="#rfc.section.11.4">11.4</a> <a id="header.from" href="#header.from">From</a></h2>2675 <p id="rfc.section.1 1.4.p.1">The "From" header field, if given, <em class="bcp14">SHOULD</em> contain an Internet e-mail address for the human user who controls the requesting user agent. The address <em class="bcp14">SHOULD</em> be machine-usable, as defined by "mailbox" in <a href="http://tools.ietf.org/html/rfc5322#section-3.4">Section 3.4</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.3"><cite title="Internet Message Format">[RFC5322]</cite></a>:2669 <h2 id="rfc.section.10.4"><a href="#rfc.section.10.4">10.4</a> <a id="header.from" href="#header.from">From</a></h2> 2670 <p id="rfc.section.10.4.p.1">The "From" header field, if given, <em class="bcp14">SHOULD</em> contain an Internet e-mail address for the human user who controls the requesting user agent. The address <em class="bcp14">SHOULD</em> be machine-usable, as defined by "mailbox" in <a href="http://tools.ietf.org/html/rfc5322#section-3.4">Section 3.4</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.3"><cite title="Internet Message Format">[RFC5322]</cite></a>: 2676 2671 </p> 2677 2672 <div id="rfc.figure.u.30"></div><pre class="inline"><span id="rfc.iref.g.41"></span> <a href="#header.from" class="smpl">From</a> = <a href="#header.from" class="smpl">mailbox</a> 2678 2673 2679 2674 <a href="#header.from" class="smpl">mailbox</a> = <mailbox, defined in <a href="#RFC5322" id="rfc.xref.RFC5322.4"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.4">Section 3.4</a>> 2680 </pre><p id="rfc.section.1 1.4.p.3">An example is:</p>2675 </pre><p id="rfc.section.10.4.p.3">An example is:</p> 2681 2676 <div id="rfc.figure.u.31"></div><pre class="text"> From: webmaster@example.org 2682 </pre><p id="rfc.section.1 1.4.p.5">This header field <em class="bcp14">MAY</em> be used for logging purposes and as a means for identifying the source of invalid or unwanted requests. It <em class="bcp14">SHOULD NOT</em> be used as an insecure form of access protection. The interpretation of this field is that the request is being performed2677 </pre><p id="rfc.section.10.4.p.5">This header field <em class="bcp14">MAY</em> be used for logging purposes and as a means for identifying the source of invalid or unwanted requests. It <em class="bcp14">SHOULD NOT</em> be used as an insecure form of access protection. The interpretation of this field is that the request is being performed 2683 2678 on behalf of the person given, who accepts responsibility for the method performed. In particular, robot agents <em class="bcp14">SHOULD</em> include this header field so that the person responsible for running the robot can be contacted if problems occur on the receiving 2684 2679 end. 2685 2680 </p> 2686 <p id="rfc.section.1 1.4.p.6">The Internet e-mail address in this field <em class="bcp14">MAY</em> be separate from the Internet host which issued the request. For example, when a request is passed through a proxy the original2681 <p id="rfc.section.10.4.p.6">The Internet e-mail address in this field <em class="bcp14">MAY</em> be separate from the Internet host which issued the request. For example, when a request is passed through a proxy the original 2687 2682 issuer's address <em class="bcp14">SHOULD</em> be used. 2688 2683 </p> 2689 <p id="rfc.section.1 1.4.p.7">The client <em class="bcp14">SHOULD NOT</em> send the From header field without the user's approval, as it might conflict with the user's privacy interests or their site's2684 <p id="rfc.section.10.4.p.7">The client <em class="bcp14">SHOULD NOT</em> send the From header field without the user's approval, as it might conflict with the user's privacy interests or their site's 2690 2685 security policy. It is strongly recommended that the user be able to disable, enable, and modify the value of this field at 2691 2686 any time prior to a request. … … 2693 2688 <div id="rfc.iref.l.1"></div> 2694 2689 <div id="rfc.iref.h.6"></div> 2695 <h2 id="rfc.section.1 1.5"><a href="#rfc.section.11.5">11.5</a> <a id="header.location" href="#header.location">Location</a></h2>2696 <p id="rfc.section.1 1.5.p.1">The "Location" header field <em class="bcp14">MAY</em> be sent in responses to refer to a specific resource in accordance with the semantics of the status code.2690 <h2 id="rfc.section.10.5"><a href="#rfc.section.10.5">10.5</a> <a id="header.location" href="#header.location">Location</a></h2> 2691 <p id="rfc.section.10.5.p.1">The "Location" header field <em class="bcp14">MAY</em> be sent in responses to refer to a specific resource in accordance with the semantics of the status code. 2697 2692 </p> 2698 2693 <div id="rfc.figure.u.32"></div><pre class="inline"><span id="rfc.iref.g.42"></span> <a href="#header.location" class="smpl">Location</a> = <a href="#abnf.dependencies" class="smpl">URI-reference</a> 2699 </pre><p id="rfc.section.1 1.5.p.3">For 201 (Created) responses, the Location is the URI of the new resource which was created by the request. For 3xx responses,2694 </pre><p id="rfc.section.10.5.p.3">For 201 (Created) responses, the Location is the URI of the new resource which was created by the request. For 3xx responses, 2700 2695 the location <em class="bcp14">SHOULD</em> indicate the server's preferred URI for automatic redirection to the resource. 2701 2696 </p> 2702 <p id="rfc.section.1 1.5.p.4">The field value consists of a single URI-reference. When it has the form of a relative reference (<a href="#RFC3986" id="rfc.xref.RFC3986.1"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-4.2">Section 4.2</a>), the final value is computed by resolving it against the effective request URI (<a href="#RFC3986" id="rfc.xref.RFC3986.2"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-5">Section 5</a>). If the original URI, as navigated to by the user agent, did contain a fragment identifier, and the final value does not,2697 <p id="rfc.section.10.5.p.4">The field value consists of a single URI-reference. When it has the form of a relative reference (<a href="#RFC3986" id="rfc.xref.RFC3986.1"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-4.2">Section 4.2</a>), the final value is computed by resolving it against the effective request URI (<a href="#RFC3986" id="rfc.xref.RFC3986.2"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-5">Section 5</a>). If the original URI, as navigated to by the user agent, did contain a fragment identifier, and the final value does not, 2703 2698 then the original URI's fragment identifier is added to the final value. 2704 2699 </p> … … 2709 2704 <p>An original URI "http://www.example.org/index.html#larry", combined with a field value given as:</p> <pre class="text"> Location: http://www.example.net/index.html 2710 2705 </pre> <p>would result in a final value of "http://www.example.net/index.html#larry", preserving the original fragment identifier.</p> 2711 <div class="note" id="rfc.section.1 1.5.p.7">2706 <div class="note" id="rfc.section.10.5.p.7"> 2712 2707 <p> <b>Note:</b> Some recipients attempt to recover from Location fields that are not valid URI references. This specification does not mandate 2713 2708 or define such processing, but does allow it (see <a href="#intro.conformance.and.error.handling" title="Conformance and Error Handling">Section 1.2</a>). 2714 2709 </p> 2715 2710 </div> 2716 <p id="rfc.section.1 1.5.p.8">There are circumstances in which a fragment identifier in a Location URI would not be appropriate. For instance, when it appears2711 <p id="rfc.section.10.5.p.8">There are circumstances in which a fragment identifier in a Location URI would not be appropriate. For instance, when it appears 2717 2712 in a 201 Created response, where the Location header field specifies the URI for the entire created resource. 2718 2713 </p> 2719 <div class="note" id="rfc.section.1 1.5.p.9">2720 <p> <b>Note:</b> The Content-Location header field (<a href="#header.content-location" id="rfc.xref.header.content-location.3" title="Content-Location">Section 1 1.17</a>) differs from Location in that the Content-Location identifies the most specific resource corresponding to the enclosed representation.2714 <div class="note" id="rfc.section.10.5.p.9"> 2715 <p> <b>Note:</b> The Content-Location header field (<a href="#header.content-location" id="rfc.xref.header.content-location.3" title="Content-Location">Section 10.17</a>) differs from Location in that the Content-Location identifies the most specific resource corresponding to the enclosed representation. 2721 2716 It is therefore possible for a response to contain header fields for both Location and Content-Location. 2722 2717 </p> … … 2724 2719 <div id="rfc.iref.m.9"></div> 2725 2720 <div id="rfc.iref.h.7"></div> 2726 <h2 id="rfc.section.1 1.6"><a href="#rfc.section.11.6">11.6</a> <a id="header.max-forwards" href="#header.max-forwards">Max-Forwards</a></h2>2727 <p id="rfc.section.1 1.6.p.1">The "Max-Forwards" header field provides a mechanism with the TRACE (<a href="#TRACE" id="rfc.xref.TRACE.1" title="TRACE">Section 2.3.7</a>) and OPTIONS (<a href="#OPTIONS" id="rfc.xref.OPTIONS.1" title="OPTIONS">Section 2.3.1</a>) methods to limit the number of times that the request is forwarded by proxies. This can be useful when the client is attempting2721 <h2 id="rfc.section.10.6"><a href="#rfc.section.10.6">10.6</a> <a id="header.max-forwards" href="#header.max-forwards">Max-Forwards</a></h2> 2722 <p id="rfc.section.10.6.p.1">The "Max-Forwards" header field provides a mechanism with the TRACE (<a href="#TRACE" id="rfc.xref.TRACE.1" title="TRACE">Section 2.3.7</a>) and OPTIONS (<a href="#OPTIONS" id="rfc.xref.OPTIONS.1" title="OPTIONS">Section 2.3.1</a>) methods to limit the number of times that the request is forwarded by proxies. This can be useful when the client is attempting 2728 2723 to trace a request which appears to be failing or looping mid-chain. 2729 2724 </p> 2730 2725 <div id="rfc.figure.u.35"></div><pre class="inline"><span id="rfc.iref.g.43"></span> <a href="#header.max-forwards" class="smpl">Max-Forwards</a> = 1*<a href="#notation" class="smpl">DIGIT</a> 2731 </pre><p id="rfc.section.1 1.6.p.3">The Max-Forwards value is a decimal integer indicating the remaining number of times this request message can be forwarded.</p>2732 <p id="rfc.section.1 1.6.p.4">Each recipient of a TRACE or OPTIONS request containing a Max-Forwards header field <em class="bcp14">MUST</em> check and update its value prior to forwarding the request. If the received value is zero (0), the recipient <em class="bcp14">MUST NOT</em> forward the request; instead, it <em class="bcp14">MUST</em> respond as the final recipient. If the received Max-Forwards value is greater than zero, then the forwarded message <em class="bcp14">MUST</em> contain an updated Max-Forwards field with a value decremented by one (1).2733 </p> 2734 <p id="rfc.section.1 1.6.p.5">The Max-Forwards header field <em class="bcp14">MAY</em> be ignored for all other request methods.2726 </pre><p id="rfc.section.10.6.p.3">The Max-Forwards value is a decimal integer indicating the remaining number of times this request message can be forwarded.</p> 2727 <p id="rfc.section.10.6.p.4">Each recipient of a TRACE or OPTIONS request containing a Max-Forwards header field <em class="bcp14">MUST</em> check and update its value prior to forwarding the request. If the received value is zero (0), the recipient <em class="bcp14">MUST NOT</em> forward the request; instead, it <em class="bcp14">MUST</em> respond as the final recipient. If the received Max-Forwards value is greater than zero, then the forwarded message <em class="bcp14">MUST</em> contain an updated Max-Forwards field with a value decremented by one (1). 2728 </p> 2729 <p id="rfc.section.10.6.p.5">The Max-Forwards header field <em class="bcp14">MAY</em> be ignored for all other request methods. 2735 2730 </p> 2736 2731 <div id="rfc.iref.r.2"></div> 2737 2732 <div id="rfc.iref.h.8"></div> 2738 <h2 id="rfc.section.1 1.7"><a href="#rfc.section.11.7">11.7</a> <a id="header.referer" href="#header.referer">Referer</a></h2>2739 <p id="rfc.section.1 1.7.p.1">The "Referer" [sic] header field allows the client to specify the URI of the resource from which the target URI was obtained2733 <h2 id="rfc.section.10.7"><a href="#rfc.section.10.7">10.7</a> <a id="header.referer" href="#header.referer">Referer</a></h2> 2734 <p id="rfc.section.10.7.p.1">The "Referer" [sic] header field allows the client to specify the URI of the resource from which the target URI was obtained 2740 2735 (the "referrer", although the header field is misspelled.). 2741 2736 </p> 2742 <p id="rfc.section.1 1.7.p.2">The Referer header field allows servers to generate lists of back-links to resources for interest, logging, optimized caching,2737 <p id="rfc.section.10.7.p.2">The Referer header field allows servers to generate lists of back-links to resources for interest, logging, optimized caching, 2743 2738 etc. It also allows obsolete or mistyped links to be traced for maintenance. Some servers use Referer as a means of controlling 2744 2739 where they allow links from (so-called "deep linking"), but legitimate requests do not always contain a Referer header field. 2745 2740 </p> 2746 <p id="rfc.section.1 1.7.p.3">If the target URI was obtained from a source that does not have its own URI (e.g., input from the user keyboard), the Referer2741 <p id="rfc.section.10.7.p.3">If the target URI was obtained from a source that does not have its own URI (e.g., input from the user keyboard), the Referer 2747 2742 field <em class="bcp14">MUST</em> either be sent with the value "about:blank", or not be sent at all. Note that this requirement does not apply to sources with 2748 2743 non-HTTP URIs (e.g., FTP). 2749 2744 </p> 2750 2745 <div id="rfc.figure.u.36"></div><pre class="inline"><span id="rfc.iref.g.44"></span> <a href="#header.referer" class="smpl">Referer</a> = <a href="#abnf.dependencies" class="smpl">absolute-URI</a> / <a href="#abnf.dependencies" class="smpl">partial-URI</a> 2751 </pre><p id="rfc.section.1 1.7.p.5">Example:</p>2746 </pre><p id="rfc.section.10.7.p.5">Example:</p> 2752 2747 <div id="rfc.figure.u.37"></div><pre class="text"> Referer: http://www.example.org/hypertext/Overview.html 2753 </pre><p id="rfc.section.1 1.7.p.7">If the field value is a relative URI, it <em class="bcp14">SHOULD</em> be interpreted relative to the effective request URI. The URI <em class="bcp14">MUST NOT</em> include a fragment. See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section 13.2</a> for security considerations.2748 </pre><p id="rfc.section.10.7.p.7">If the field value is a relative URI, it <em class="bcp14">SHOULD</em> be interpreted relative to the effective request URI. The URI <em class="bcp14">MUST NOT</em> include a fragment. See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section 12.2</a> for security considerations. 2754 2749 </p> 2755 2750 <div id="rfc.iref.r.3"></div> 2756 2751 <div id="rfc.iref.h.9"></div> 2757 <h2 id="rfc.section.1 1.8"><a href="#rfc.section.11.8">11.8</a> <a id="header.retry-after" href="#header.retry-after">Retry-After</a></h2>2758 <p id="rfc.section.1 1.8.p.1">The header "Retry-After" field can be used with a 503 (Service Unavailable) response to indicate how long the service is expected2752 <h2 id="rfc.section.10.8"><a href="#rfc.section.10.8">10.8</a> <a id="header.retry-after" href="#header.retry-after">Retry-After</a></h2> 2753 <p id="rfc.section.10.8.p.1">The header "Retry-After" field can be used with a 503 (Service Unavailable) response to indicate how long the service is expected 2759 2754 to be unavailable to the requesting client. This field <em class="bcp14">MAY</em> also be used with any 3xx (Redirection) response to indicate the minimum time the user-agent is asked to wait before issuing 2760 2755 the redirected request. 2761 2756 </p> 2762 <p id="rfc.section.1 1.8.p.2">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.</p>2757 <p id="rfc.section.10.8.p.2">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.</p> 2763 2758 <div id="rfc.figure.u.38"></div><pre class="inline"><span id="rfc.iref.g.45"></span> <a href="#header.retry-after" class="smpl">Retry-After</a> = <a href="#http.date" class="smpl">HTTP-date</a> / <a href="#rule.delta-seconds" class="smpl">delta-seconds</a> 2764 2759 </pre><div id="rule.delta-seconds"> 2765 <p id="rfc.section.1 1.8.p.4"> Time spans are non-negative decimal integers, representing time in seconds.</p>2760 <p id="rfc.section.10.8.p.4"> Time spans are non-negative decimal integers, representing time in seconds.</p> 2766 2761 </div> 2767 2762 <div id="rfc.figure.u.39"></div><pre class="inline"><span id="rfc.iref.g.46"></span> <a href="#rule.delta-seconds" class="smpl">delta-seconds</a> = 1*<a href="#notation" class="smpl">DIGIT</a> 2768 </pre><p id="rfc.section.1 1.8.p.6">Two examples of its use are</p>2763 </pre><p id="rfc.section.10.8.p.6">Two examples of its use are</p> 2769 2764 <div id="rfc.figure.u.40"></div><pre class="text"> Retry-After: Fri, 31 Dec 1999 23:59:59 GMT 2770 2765 Retry-After: 120 2771 </pre><p id="rfc.section.1 1.8.p.8">In the latter example, the delay is 2 minutes.</p>2766 </pre><p id="rfc.section.10.8.p.8">In the latter example, the delay is 2 minutes.</p> 2772 2767 <div id="rfc.iref.s.39"></div> 2773 2768 <div id="rfc.iref.h.10"></div> 2774 <h2 id="rfc.section.1 1.9"><a href="#rfc.section.11.9">11.9</a> <a id="header.server" href="#header.server">Server</a></h2>2775 <p id="rfc.section.1 1.9.p.1">The "Server" header field contains information about the software used by the origin server to handle the request.</p>2776 <p id="rfc.section.1 1.9.p.2">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section 6.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.46"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>) identifying the server and any significant subproducts. The product tokens are listed in order of their significance for2769 <h2 id="rfc.section.10.9"><a href="#rfc.section.10.9">10.9</a> <a id="header.server" href="#header.server">Server</a></h2> 2770 <p id="rfc.section.10.9.p.1">The "Server" header field contains information about the software used by the origin server to handle the request.</p> 2771 <p id="rfc.section.10.9.p.2">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section 6.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.46"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>) identifying the server and any significant subproducts. The product tokens are listed in order of their significance for 2777 2772 identifying the application. 2778 2773 </p> 2779 2774 <div id="rfc.figure.u.41"></div><pre class="inline"><span id="rfc.iref.g.47"></span> <a href="#header.server" class="smpl">Server</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#core.rules" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#abnf.dependencies" class="smpl">comment</a> ) ) 2780 </pre><p id="rfc.section.1 1.9.p.4">Example:</p>2775 </pre><p id="rfc.section.10.9.p.4">Example:</p> 2781 2776 <div id="rfc.figure.u.42"></div><pre class="text"> Server: CERN/3.0 libwww/2.17 2782 </pre><p id="rfc.section.1 1.9.p.6">If the response is being forwarded through a proxy, the proxy application <em class="bcp14">MUST NOT</em> modify the Server header field. Instead, it <em class="bcp14">MUST</em> include a Via field (as described in <a href="p1-messaging.html#header.via" title="Via">Section 6.2</a> of <a href="#Part1" id="rfc.xref.Part1.47"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>).2783 </p> 2784 <div class="note" id="rfc.section.1 1.9.p.7">2777 </pre><p id="rfc.section.10.9.p.6">If the response is being forwarded through a proxy, the proxy application <em class="bcp14">MUST NOT</em> modify the Server header field. Instead, it <em class="bcp14">MUST</em> include a Via field (as described in <a href="p1-messaging.html#header.via" title="Via">Section 6.2</a> of <a href="#Part1" id="rfc.xref.Part1.47"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>). 2778 </p> 2779 <div class="note" id="rfc.section.10.9.p.7"> 2785 2780 <p> <b>Note:</b> Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks 2786 2781 against software that is known to contain security holes. Server implementors are encouraged to make this field a configurable … … 2790 2785 <div id="rfc.iref.u.1"></div> 2791 2786 <div id="rfc.iref.h.11"></div> 2792 <h2 id="rfc.section.1 1.10"><a href="#rfc.section.11.10">11.10</a> <a id="header.user-agent" href="#header.user-agent">User-Agent</a></h2>2793 <p id="rfc.section.1 1.10.p.1">The "User-Agent" header field contains information about the user agent originating the request. User agents <em class="bcp14">SHOULD</em> include this field with requests.2794 </p> 2795 <p id="rfc.section.1 1.10.p.2">Typically, it is used for statistical purposes, the tracing of protocol violations, and tailoring responses to avoid particular2787 <h2 id="rfc.section.10.10"><a href="#rfc.section.10.10">10.10</a> <a id="header.user-agent" href="#header.user-agent">User-Agent</a></h2> 2788 <p id="rfc.section.10.10.p.1">The "User-Agent" header field contains information about the user agent originating the request. User agents <em class="bcp14">SHOULD</em> include this field with requests. 2789 </p> 2790 <p id="rfc.section.10.10.p.2">Typically, it is used for statistical purposes, the tracing of protocol violations, and tailoring responses to avoid particular 2796 2791 user agent limitations. 2797 2792 </p> 2798 <p id="rfc.section.1 1.10.p.3">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section 6.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.48"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>) identifying the agent and its significant subproducts. By convention, the product tokens are listed in order of their significance2793 <p id="rfc.section.10.10.p.3">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section 6.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.48"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>) identifying the agent and its significant subproducts. By convention, the product tokens are listed in order of their significance 2799 2794 for identifying the application. 2800 2795 </p> 2801 <p id="rfc.section.1 1.10.p.4">Because this field is usually sent on every request a user agent makes, implementations are encouraged not to include needlessly2796 <p id="rfc.section.10.10.p.4">Because this field is usually sent on every request a user agent makes, implementations are encouraged not to include needlessly 2802 2797 fine-grained detail, and to limit (or even prohibit) the addition of subproducts by third parties. Overly long and detailed 2803 2798 User-Agent field values make requests larger and can also be used to identify ("fingerprint") the user against their wishes. 2804 2799 </p> 2805 <p id="rfc.section.1 1.10.p.5">Likewise, implementations are encouraged not to use the product tokens of other implementations in order to declare compatibility2800 <p id="rfc.section.10.10.p.5">Likewise, implementations are encouraged not to use the product tokens of other implementations in order to declare compatibility 2806 2801 with them, as this circumvents the purpose of the field. Finally, they are encouraged not to use comments to identify products; 2807 2802 doing so makes the field value more difficult to parse. 2808 2803 </p> 2809 2804 <div id="rfc.figure.u.43"></div><pre class="inline"><span id="rfc.iref.g.48"></span> <a href="#header.user-agent" class="smpl">User-Agent</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#core.rules" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#abnf.dependencies" class="smpl">comment</a> ) ) 2810 </pre><p id="rfc.section.1 1.10.p.7">Example:</p>2805 </pre><p id="rfc.section.10.10.p.7">Example:</p> 2811 2806 <div id="rfc.figure.u.44"></div><pre class="text"> User-Agent: CERN-LineMode/2.15 libwww/2.17b3 2812 2807 </pre><div id="rfc.iref.a.2"></div> 2813 2808 <div id="rfc.iref.h.12"></div> 2814 <h2 id="rfc.section.1 1.11"><a href="#rfc.section.11.11">11.11</a> <a id="header.accept" href="#header.accept">Accept</a></h2>2815 <p id="rfc.section.1 1.11.p.1">The "Accept" header field can be used by user agents to specify response media types that are acceptable. Accept header fields2809 <h2 id="rfc.section.10.11"><a href="#rfc.section.10.11">10.11</a> <a id="header.accept" href="#header.accept">Accept</a></h2> 2810 <p id="rfc.section.10.11.p.1">The "Accept" header field can be used by user agents to specify response media types that are acceptable. Accept header fields 2816 2811 can be used to indicate that the request is specifically limited to a small set of desired types, as in the case of a request 2817 2812 for an in-line image. … … 2825 2820 <a href="#header.accept" class="smpl">accept-params</a> = <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> "q=" qvalue *( <a href="#header.accept" class="smpl">accept-ext</a> ) 2826 2821 <a href="#header.accept" class="smpl">accept-ext</a> = <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> <a href="#core.rules" class="smpl">token</a> [ "=" word ] 2827 </pre><p id="rfc.section.1 1.11.p.3">The asterisk "*" character is used to group media types into ranges, with "*/*" indicating all media types and "type/*" indicating2822 </pre><p id="rfc.section.10.11.p.3">The asterisk "*" character is used to group media types into ranges, with "*/*" indicating all media types and "type/*" indicating 2828 2823 all subtypes of that type. The media-range <em class="bcp14">MAY</em> include media type parameters that are applicable to that range. 2829 2824 </p> 2830 <p id="rfc.section.1 1.11.p.4">Each media-range <em class="bcp14">MAY</em> be followed by one or more accept-params, beginning with the "q" parameter for indicating a relative quality factor. The first2825 <p id="rfc.section.10.11.p.4">Each media-range <em class="bcp14">MAY</em> be followed by one or more accept-params, beginning with the "q" parameter for indicating a relative quality factor. The first 2831 2826 "q" parameter (if any) separates the media-range parameter(s) from the accept-params. Quality factors allow the user or user 2832 2827 agent to indicate the relative degree of preference for that media-range, using the qvalue scale from 0 to 1 (qvalue;). The 2833 2828 default value is q=1. 2834 2829 </p> 2835 <div class="note" id="rfc.section.1 1.11.p.5">2830 <div class="note" id="rfc.section.10.11.p.5"> 2836 2831 <p> <b>Note:</b> Use of the "q" parameter name to separate media type parameters from Accept extension parameters is due to historical practice. 2837 2832 Although this prevents any media type parameter named "q" from being used with a media range, such an event is believed to … … 2840 2835 </p> 2841 2836 </div> 2842 <p id="rfc.section.1 1.11.p.6">The example</p>2837 <p id="rfc.section.10.11.p.6">The example</p> 2843 2838 <div id="rfc.figure.u.46"></div><pre class="text"> Accept: audio/*; q=0.2, audio/basic 2844 </pre><p id="rfc.section.1 1.11.p.8"> <em class="bcp14">SHOULD</em> be interpreted as "I prefer audio/basic, but send me any audio type if it is the best available after an 80% mark-down in2839 </pre><p id="rfc.section.10.11.p.8"> <em class="bcp14">SHOULD</em> be interpreted as "I prefer audio/basic, but send me any audio type if it is the best available after an 80% mark-down in 2845 2840 quality". 2846 2841 </p> 2847 <p id="rfc.section.1 1.11.p.9">A request without any Accept header field implies that the user agent will accept any media type in response. If an Accept2842 <p id="rfc.section.10.11.p.9">A request without any Accept header field implies that the user agent will accept any media type in response. If an Accept 2848 2843 header field is present in a request and none of the available representations for the response have a media type that is 2849 2844 listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept header field by sending a 406 (Not Acceptable) response or disregard the Accept header field by treating 2850 2845 the response as if it is not subject to content negotiation. 2851 2846 </p> 2852 <p id="rfc.section.1 1.11.p.10">A more elaborate example is</p>2847 <p id="rfc.section.10.11.p.10">A more elaborate example is</p> 2853 2848 <div id="rfc.figure.u.47"></div><pre class="text"> Accept: text/plain; q=0.5, text/html, 2854 2849 text/x-dvi; q=0.8, text/x-c 2855 </pre><p id="rfc.section.1 1.11.p.12">Verbally, this would be interpreted as "text/html and text/x-c are the preferred media types, but if they do not exist, then2850 </pre><p id="rfc.section.10.11.p.12">Verbally, this would be interpreted as "text/html and text/x-c are the preferred media types, but if they do not exist, then 2856 2851 send the text/x-dvi representation, and if that does not exist, send the text/plain representation". 2857 2852 </p> 2858 <p id="rfc.section.1 1.11.p.13">Media ranges can be overridden by more specific media ranges or specific media types. If more than one media range applies2853 <p id="rfc.section.10.11.p.13">Media ranges can be overridden by more specific media ranges or specific media types. If more than one media range applies 2859 2854 to a given type, the most specific reference has precedence. For example, 2860 2855 </p> 2861 2856 <div id="rfc.figure.u.48"></div><pre class="text"> Accept: text/*, text/plain, text/plain;format=flowed, */* 2862 </pre><p id="rfc.section.1 1.11.p.15">have the following precedence: </p>2857 </pre><p id="rfc.section.10.11.p.15">have the following precedence: </p> 2863 2858 <ol> 2864 2859 <li>text/plain;format=flowed</li> … … 2867 2862 <li>*/*</li> 2868 2863 </ol> 2869 <p id="rfc.section.1 1.11.p.16">The media type quality factor associated with a given type is determined by finding the media range with the highest precedence2864 <p id="rfc.section.10.11.p.16">The media type quality factor associated with a given type is determined by finding the media range with the highest precedence 2870 2865 which matches that type. For example, 2871 2866 </p> 2872 2867 <div id="rfc.figure.u.49"></div><pre class="text"> Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1, 2873 2868 text/html;level=2;q=0.4, */*;q=0.5 2874 </pre><p id="rfc.section.1 1.11.p.18">would cause the following values to be associated:</p>2869 </pre><p id="rfc.section.10.11.p.18">would cause the following values to be associated:</p> 2875 2870 <div id="rfc.table.u.7"> 2876 2871 <table class="tt full left" cellpadding="3" cellspacing="0"> … … 2909 2904 </table> 2910 2905 </div> 2911 <p id="rfc.section.1 1.11.p.19"> <b>Note:</b> A user agent might be provided with a default set of quality values for certain media ranges. However, unless the user agent2906 <p id="rfc.section.10.11.p.19"> <b>Note:</b> A user agent might be provided with a default set of quality values for certain media ranges. However, unless the user agent 2912 2907 is a closed system which cannot interact with other rendering agents, this default set ought to be configurable by the user. 2913 2908 </p> 2914 2909 <div id="rfc.iref.a.3"></div> 2915 2910 <div id="rfc.iref.h.13"></div> 2916 <h2 id="rfc.section.1 1.12"><a href="#rfc.section.11.12">11.12</a> <a id="header.accept-charset" href="#header.accept-charset">Accept-Charset</a></h2>2917 <p id="rfc.section.1 1.12.p.1">The "Accept-Charset" header field can be used by user agents to indicate what character encodings are acceptable in a response2911 <h2 id="rfc.section.10.12"><a href="#rfc.section.10.12">10.12</a> <a id="header.accept-charset" href="#header.accept-charset">Accept-Charset</a></h2> 2912 <p id="rfc.section.10.12.p.1">The "Accept-Charset" header field can be used by user agents to indicate what character encodings are acceptable in a response 2918 2913 payload. This field allows clients capable of understanding more comprehensive or special-purpose character encodings to signal 2919 2914 that capability to a server which is capable of representing documents in those character encodings. … … 2921 2916 <div id="rfc.figure.u.50"></div><pre class="inline"><span id="rfc.iref.g.53"></span> <a href="#header.accept-charset" class="smpl">Accept-Charset</a> = 1#( ( <a href="#rule.charset" class="smpl">charset</a> / "*" ) 2922 2917 [ <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> "q=" qvalue ] ) 2923 </pre><p id="rfc.section.1 1.12.p.3">Character encoding values (a.k.a., charsets) are described in <a href="#character.sets" title="Character Encodings (charset)">Section 7.1</a>. Each charset <em class="bcp14">MAY</em> be given an associated quality value which represents the user's preference for that charset. The default value is q=1. An2918 </pre><p id="rfc.section.10.12.p.3">Character encoding values (a.k.a., charsets) are described in <a href="#character.sets" title="Character Encodings (charset)">Section 6.3</a>. Each charset <em class="bcp14">MAY</em> be given an associated quality value which represents the user's preference for that charset. The default value is q=1. An 2924 2919 example is 2925 2920 </p> 2926 2921 <div id="rfc.figure.u.51"></div><pre class="text"> Accept-Charset: iso-8859-5, unicode-1-1;q=0.8 2927 </pre><p id="rfc.section.1 1.12.p.5">The special value "*", if present in the Accept-Charset field, matches every character encoding which is not mentioned elsewhere2922 </pre><p id="rfc.section.10.12.p.5">The special value "*", if present in the Accept-Charset field, matches every character encoding which is not mentioned elsewhere 2928 2923 in the Accept-Charset field. If no "*" is present in an Accept-Charset field, then all character encodings not explicitly 2929 2924 mentioned get a quality value of 0. 2930 2925 </p> 2931 <p id="rfc.section.1 1.12.p.6">A request without any Accept-Charset header field implies that the user agent will accept any character encoding in response.2926 <p id="rfc.section.10.12.p.6">A request without any Accept-Charset header field implies that the user agent will accept any character encoding in response. 2932 2927 If an Accept-Charset header field is present in a request and none of the available representations for the response have 2933 2928 a character encoding that is listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept-Charset header field by sending a 406 (Not Acceptable) response or disregard the Accept-Charset header … … 2936 2931 <div id="rfc.iref.a.4"></div> 2937 2932 <div id="rfc.iref.h.14"></div> 2938 <h2 id="rfc.section.1 1.13"><a href="#rfc.section.11.13">11.13</a> <a id="header.accept-encoding" href="#header.accept-encoding">Accept-Encoding</a></h2>2939 <p id="rfc.section.1 1.13.p.1">The "Accept-Encoding" header field can be used by user agents to indicate what response content-codings (<a href="#content.codings" title="Content Codings">Section 7.2</a>) are acceptable in the response. An "identity" token is used as a synonym for "no encoding" in order to communicate when2933 <h2 id="rfc.section.10.13"><a href="#rfc.section.10.13">10.13</a> <a id="header.accept-encoding" href="#header.accept-encoding">Accept-Encoding</a></h2> 2934 <p id="rfc.section.10.13.p.1">The "Accept-Encoding" header field can be used by user agents to indicate what response content-codings (<a href="#content.codings" title="Content Codings">Section 6.4</a>) are acceptable in the response. An "identity" token is used as a synonym for "no encoding" in order to communicate when 2940 2935 no encoding is preferred. 2941 2936 </p> 2942 2937 <div id="rfc.figure.u.52"></div><pre class="inline"><span id="rfc.iref.g.54"></span><span id="rfc.iref.g.55"></span> <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> = #( <a href="#header.accept-encoding" class="smpl">codings</a> [ <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> "q=" qvalue ] ) 2943 2938 <a href="#header.accept-encoding" class="smpl">codings</a> = <a href="#content.codings" class="smpl">content-coding</a> / "identity" / "*" 2944 </pre><p id="rfc.section.1 1.13.p.3">Each codings value <em class="bcp14">MAY</em> be given an associated quality value which represents the preference for that encoding. The default value is q=1.2945 </p> 2946 <p id="rfc.section.1 1.13.p.4">For example,</p>2939 </pre><p id="rfc.section.10.13.p.3">Each codings value <em class="bcp14">MAY</em> be given an associated quality value which represents the preference for that encoding. The default value is q=1. 2940 </p> 2941 <p id="rfc.section.10.13.p.4">For example,</p> 2947 2942 <div id="rfc.figure.u.53"></div><pre class="text"> Accept-Encoding: compress, gzip 2948 2943 Accept-Encoding: … … 2950 2945 Accept-Encoding: compress;q=0.5, gzip;q=1.0 2951 2946 Accept-Encoding: gzip;q=1.0, identity; q=0.5, *;q=0 2952 </pre><p id="rfc.section.1 1.13.p.6">A server tests whether a content-coding for a given representation is acceptable, according to an Accept-Encoding field, using2947 </pre><p id="rfc.section.10.13.p.6">A server tests whether a content-coding for a given representation is acceptable, according to an Accept-Encoding field, using 2953 2948 these rules: 2954 2949 </p> … … 2965 2960 <li>If multiple content-codings are acceptable, then the acceptable content-coding with the highest non-zero qvalue is preferred.</li> 2966 2961 </ol> 2967 <p id="rfc.section.1 1.13.p.7">An Accept-Encoding header field with a combined field-value that is empty implies that the user agent does not want any content-coding2962 <p id="rfc.section.10.13.p.7">An Accept-Encoding header field with a combined field-value that is empty implies that the user agent does not want any content-coding 2968 2963 in response. If an Accept-Encoding header field is present in a request and none of the available representations for the 2969 2964 response have a content-coding that is listed as acceptable, the origin server <em class="bcp14">SHOULD</em> send a response without any content-coding. 2970 2965 </p> 2971 <p id="rfc.section.1 1.13.p.8">A request without an Accept-Encoding header field implies that the user agent will accept any content-coding in response,2966 <p id="rfc.section.10.13.p.8">A request without an Accept-Encoding header field implies that the user agent will accept any content-coding in response, 2972 2967 but a representation without content-coding is preferred for compatibility with the widest variety of user agents. 2973 2968 </p> 2974 <div class="note" id="rfc.section.1 1.13.p.9">2969 <div class="note" id="rfc.section.10.13.p.9"> 2975 2970 <p> <b>Note:</b> Most HTTP/1.0 applications do not recognize or obey qvalues associated with content-codings. This means that qvalues will 2976 2971 not work and are not permitted with x-gzip or x-compress. … … 2979 2974 <div id="rfc.iref.a.5"></div> 2980 2975 <div id="rfc.iref.h.15"></div> 2981 <h2 id="rfc.section.1 1.14"><a href="#rfc.section.11.14">11.14</a> <a id="header.accept-language" href="#header.accept-language">Accept-Language</a></h2>2982 <p id="rfc.section.1 1.14.p.1">The "Accept-Language" header field can be used by user agents to indicate the set of natural languages that are preferred2983 in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section 7.4</a>.2976 <h2 id="rfc.section.10.14"><a href="#rfc.section.10.14">10.14</a> <a id="header.accept-language" href="#header.accept-language">Accept-Language</a></h2> 2977 <p id="rfc.section.10.14.p.1">The "Accept-Language" header field can be used by user agents to indicate the set of natural languages that are preferred 2978 in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section 6.6</a>. 2984 2979 </p> 2985 2980 <div id="rfc.figure.u.54"></div><pre class="inline"><span id="rfc.iref.g.56"></span><span id="rfc.iref.g.57"></span> <a href="#header.accept-language" class="smpl">Accept-Language</a> = … … 2987 2982 <a href="#header.accept-language" class="smpl">language-range</a> = 2988 2983 <language-range, defined in <a href="#RFC4647" id="rfc.xref.RFC4647.1"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-2.1">Section 2.1</a>> 2989 </pre><p id="rfc.section.1 1.14.p.3">Each language-range can be given an associated quality value which represents an estimate of the user's preference for the2984 </pre><p id="rfc.section.10.14.p.3">Each language-range can be given an associated quality value which represents an estimate of the user's preference for the 2990 2985 languages specified by that range. The quality value defaults to "q=1". For example, 2991 2986 </p> 2992 2987 <div id="rfc.figure.u.55"></div><pre class="text"> Accept-Language: da, en-gb;q=0.8, en;q=0.7 2993 </pre><p id="rfc.section.1 1.14.p.5">would mean: "I prefer Danish, but will accept British English and other types of English". (see also <a href="http://tools.ietf.org/html/rfc4647#section-2.3">Section 2.3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.2"><cite title="Matching of Language Tags">[RFC4647]</cite></a>)2994 </p> 2995 <p id="rfc.section.1 1.14.p.6">For matching, <a href="http://tools.ietf.org/html/rfc4647#section-3">Section 3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.3"><cite title="Matching of Language Tags">[RFC4647]</cite></a> defines several matching schemes. Implementations can offer the most appropriate matching scheme for their requirements.2996 </p> 2997 <div class="note" id="rfc.section.1 1.14.p.7">2988 </pre><p id="rfc.section.10.14.p.5">would mean: "I prefer Danish, but will accept British English and other types of English". (see also <a href="http://tools.ietf.org/html/rfc4647#section-2.3">Section 2.3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.2"><cite title="Matching of Language Tags">[RFC4647]</cite></a>) 2989 </p> 2990 <p id="rfc.section.10.14.p.6">For matching, <a href="http://tools.ietf.org/html/rfc4647#section-3">Section 3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.3"><cite title="Matching of Language Tags">[RFC4647]</cite></a> defines several matching schemes. Implementations can offer the most appropriate matching scheme for their requirements. 2991 </p> 2992 <div class="note" id="rfc.section.10.14.p.7"> 2998 2993 <p> <b>Note:</b> The "Basic Filtering" scheme (<a href="#RFC4647" id="rfc.xref.RFC4647.4"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-3.3.1">Section 3.3.1</a>) is identical to the matching scheme that was previously defined in <a href="http://tools.ietf.org/html/rfc2616#section-14.4">Section 14.4</a> of <a href="#RFC2616" id="rfc.xref.RFC2616.3"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>. 2999 2994 </p> 3000 2995 </div> 3001 <p id="rfc.section.1 1.14.p.8">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic3002 preferences of the user in every request. For a discussion of this issue, see <a href="#privacy.issues.connected.to.accept.header.fields" title="Privacy Issues Connected to Accept Header Fields">Section 1 3.5</a>.3003 </p> 3004 <p id="rfc.section.1 1.14.p.9">As intelligibility is highly dependent on the individual user, it is recommended that client applications make the choice2996 <p id="rfc.section.10.14.p.8">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic 2997 preferences of the user in every request. For a discussion of this issue, see <a href="#privacy.issues.connected.to.accept.header.fields" title="Privacy Issues Connected to Accept Header Fields">Section 12.5</a>. 2998 </p> 2999 <p id="rfc.section.10.14.p.9">As intelligibility is highly dependent on the individual user, it is recommended that client applications make the choice 3005 3000 of linguistic preference available to the user. If the choice is not made available, then the Accept-Language header field <em class="bcp14">MUST NOT</em> be given in the request. 3006 3001 </p> 3007 <div class="note" id="rfc.section.1 1.14.p.10">3002 <div class="note" id="rfc.section.10.14.p.10"> 3008 3003 <p> <b>Note:</b> When making the choice of linguistic preference available to the user, we remind implementors of the fact that users are not 3009 3004 familiar with the details of language matching as described above, and ought to be provided appropriate guidance. As an example, … … 3014 3009 <div id="rfc.iref.c.7"></div> 3015 3010 <div id="rfc.iref.h.16"></div> 3016 <h2 id="rfc.section.1 1.15"><a href="#rfc.section.11.15">11.15</a> <a id="header.content-encoding" href="#header.content-encoding">Content-Encoding</a></h2>3017 <p id="rfc.section.1 1.15.p.1">The "Content-Encoding" header field indicates what content-codings have been applied to the representation beyond those inherent3011 <h2 id="rfc.section.10.15"><a href="#rfc.section.10.15">10.15</a> <a id="header.content-encoding" href="#header.content-encoding">Content-Encoding</a></h2> 3012 <p id="rfc.section.10.15.p.1">The "Content-Encoding" header field indicates what content-codings have been applied to the representation beyond those inherent 3018 3013 in the media type, and thus what decoding mechanisms have to be applied in order to obtain the media-type referenced by the 3019 3014 Content-Type header field. Content-Encoding is primarily used to allow a representation to be compressed without losing the … … 3021 3016 </p> 3022 3017 <div id="rfc.figure.u.56"></div><pre class="inline"><span id="rfc.iref.g.58"></span> <a href="#header.content-encoding" class="smpl">Content-Encoding</a> = 1#<a href="#content.codings" class="smpl">content-coding</a> 3023 </pre><p id="rfc.section.1 1.15.p.3">Content codings are defined in <a href="#content.codings" title="Content Codings">Section 7.2</a>. An example of its use is3018 </pre><p id="rfc.section.10.15.p.3">Content codings are defined in <a href="#content.codings" title="Content Codings">Section 6.4</a>. An example of its use is 3024 3019 </p> 3025 3020 <div id="rfc.figure.u.57"></div><pre class="text"> Content-Encoding: gzip 3026 </pre><p id="rfc.section.1 1.15.p.5">The content-coding is a characteristic of the representation. Typically, the representation body is stored with this encoding3021 </pre><p id="rfc.section.10.15.p.5">The content-coding is a characteristic of the representation. Typically, the representation body is stored with this encoding 3027 3022 and is only decoded before rendering or analogous usage. However, a transforming proxy <em class="bcp14">MAY</em> modify the content-coding if the new coding is known to be acceptable to the recipient, unless the "no-transform" cache-control 3028 3023 directive is present in the message. 3029 3024 </p> 3030 <p id="rfc.section.1 1.15.p.6">If the media type includes an inherent encoding, such as a data format that is always compressed, then that encoding would3025 <p id="rfc.section.10.15.p.6">If the media type includes an inherent encoding, such as a data format that is always compressed, then that encoding would 3031 3026 not be restated as a Content-Encoding even if it happens to be the same algorithm as one of the content-codings. Such a content-coding 3032 3027 would only be listed if, for some bizarre reason, it is applied a second time to form the representation. Likewise, an origin … … 3035 3030 response (e.g., open a "Save as ..." dialog instead of automatic decompression and rendering of content). 3036 3031 </p> 3037 <p id="rfc.section.1 1.15.p.7">A representation that has a content-coding applied to it <em class="bcp14">MUST</em> include a Content-Encoding header field (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.3" title="Content-Encoding">Section 11.15</a>) that lists the content-coding(s) applied.3038 </p> 3039 <p id="rfc.section.1 1.15.p.8">If multiple encodings have been applied to a representation, the content codings <em class="bcp14">MUST</em> be listed in the order in which they were applied. Additional information about the encoding parameters <em class="bcp14">MAY</em> be provided by other header fields not defined by this specification.3040 </p> 3041 <p id="rfc.section.1 1.15.p.9">If the content-coding of a representation in a request message is not acceptable to the origin server, the server <em class="bcp14">SHOULD</em> respond with a status code of 415 (Unsupported Media Type).3032 <p id="rfc.section.10.15.p.7">A representation that has a content-coding applied to it <em class="bcp14">MUST</em> include a Content-Encoding header field (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.3" title="Content-Encoding">Section 10.15</a>) that lists the content-coding(s) applied. 3033 </p> 3034 <p id="rfc.section.10.15.p.8">If multiple encodings have been applied to a representation, the content codings <em class="bcp14">MUST</em> be listed in the order in which they were applied. Additional information about the encoding parameters <em class="bcp14">MAY</em> be provided by other header fields not defined by this specification. 3035 </p> 3036 <p id="rfc.section.10.15.p.9">If the content-coding of a representation in a request message is not acceptable to the origin server, the server <em class="bcp14">SHOULD</em> respond with a status code of 415 (Unsupported Media Type). 3042 3037 </p> 3043 3038 <div id="rfc.iref.c.8"></div> 3044 3039 <div id="rfc.iref.h.17"></div> 3045 <h2 id="rfc.section.1 1.16"><a href="#rfc.section.11.16">11.16</a> <a id="header.content-language" href="#header.content-language">Content-Language</a></h2>3046 <p id="rfc.section.1 1.16.p.1">The "Content-Language" header field describes the natural language(s) of the intended audience for the representation. Note3040 <h2 id="rfc.section.10.16"><a href="#rfc.section.10.16">10.16</a> <a id="header.content-language" href="#header.content-language">Content-Language</a></h2> 3041 <p id="rfc.section.10.16.p.1">The "Content-Language" header field describes the natural language(s) of the intended audience for the representation. Note 3047 3042 that this might not be equivalent to all the languages used within the representation. 3048 3043 </p> 3049 3044 <div id="rfc.figure.u.58"></div><pre class="inline"><span id="rfc.iref.g.59"></span> <a href="#header.content-language" class="smpl">Content-Language</a> = 1#<a href="#language.tags" class="smpl">language-tag</a> 3050 </pre><p id="rfc.section.1 1.16.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section 7.4</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the3045 </pre><p id="rfc.section.10.16.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section 6.6</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the 3051 3046 user's own preferred language. Thus, if the body content is intended only for a Danish-literate audience, the appropriate 3052 3047 field is 3053 3048 </p> 3054 3049 <div id="rfc.figure.u.59"></div><pre class="text"> Content-Language: da 3055 </pre><p id="rfc.section.1 1.16.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean3050 </pre><p id="rfc.section.10.16.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean 3056 3051 that the sender does not consider it to be specific to any natural language, or that the sender does not know for which language 3057 3052 it is intended. 3058 3053 </p> 3059 <p id="rfc.section.1 1.16.p.6">Multiple languages <em class="bcp14">MAY</em> be listed for content that is intended for multiple audiences. For example, a rendition of the "Treaty of Waitangi", presented3054 <p id="rfc.section.10.16.p.6">Multiple languages <em class="bcp14">MAY</em> be listed for content that is intended for multiple audiences. For example, a rendition of the "Treaty of Waitangi", presented 3060 3055 simultaneously in the original Maori and English versions, would call for 3061 3056 </p> 3062 3057 <div id="rfc.figure.u.60"></div><pre class="text"> Content-Language: mi, en 3063 </pre><p id="rfc.section.1 1.16.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple3058 </pre><p id="rfc.section.10.16.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple 3064 3059 linguistic audiences. An example would be a beginner's language primer, such as "A First Lesson in Latin", which is clearly 3065 3060 intended to be used by an English-literate audience. In this case, the Content-Language would properly only include "en". 3066 3061 </p> 3067 <p id="rfc.section.1 1.16.p.9">Content-Language <em class="bcp14">MAY</em> be applied to any media type — it is not limited to textual documents.3062 <p id="rfc.section.10.16.p.9">Content-Language <em class="bcp14">MAY</em> be applied to any media type — it is not limited to textual documents. 3068 3063 </p> 3069 3064 <div id="rfc.iref.c.9"></div> 3070 3065 <div id="rfc.iref.h.18"></div> 3071 <h2 id="rfc.section.1 1.17"><a href="#rfc.section.11.17">11.17</a> <a id="header.content-location" href="#header.content-location">Content-Location</a></h2>3072 <p id="rfc.section.1 1.17.p.1">The "Content-Location" header field supplies a URI that can be used as a specific identifier for the representation in this3066 <h2 id="rfc.section.10.17"><a href="#rfc.section.10.17">10.17</a> <a id="header.content-location" href="#header.content-location">Content-Location</a></h2> 3067 <p id="rfc.section.10.17.p.1">The "Content-Location" header field supplies a URI that can be used as a specific identifier for the representation in this 3073 3068 message. In other words, if one were to perform a GET on this URI at the time of this message's generation, then a 200 response 3074 3069 would contain the same representation that is enclosed as payload in this message. 3075 3070 </p> 3076 3071 <div id="rfc.figure.u.61"></div><pre class="inline"><span id="rfc.iref.g.60"></span> <a href="#header.content-location" class="smpl">Content-Location</a> = <a href="#abnf.dependencies" class="smpl">absolute-URI</a> / <a href="#abnf.dependencies" class="smpl">partial-URI</a> 3077 </pre><p id="rfc.section.1 1.17.p.3">The Content-Location value is not a replacement for the effective Request URI (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 5.5</a> of <a href="#Part1" id="rfc.xref.Part1.49"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>). It is representation metadata. It has the same syntax and semantics as the header field of the same name defined for MIME3072 </pre><p id="rfc.section.10.17.p.3">The Content-Location value is not a replacement for the effective Request URI (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 5.5</a> of <a href="#Part1" id="rfc.xref.Part1.49"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>). It is representation metadata. It has the same syntax and semantics as the header field of the same name defined for MIME 3078 3073 body parts in <a href="http://tools.ietf.org/html/rfc2557#section-4">Section 4</a> of <a href="#RFC2557" id="rfc.xref.RFC2557.1"><cite title="MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)">[RFC2557]</cite></a>. However, its appearance in an HTTP message has some special implications for HTTP recipients. 3079 3074 </p> 3080 <p id="rfc.section.1 1.17.p.4">If Content-Location is included in a response message and its value is the same as the effective request URI, then the response3075 <p id="rfc.section.10.17.p.4">If Content-Location is included in a response message and its value is the same as the effective request URI, then the response 3081 3076 payload <em class="bcp14">SHOULD</em> be considered a current representation of that resource. For a GET or HEAD request, this is the same as the default semantics 3082 3077 when no Content-Location is provided by the server. For a state-changing request like PUT or POST, it implies that the server's … … 3085 3080 need for a subsequent GET request. 3086 3081 </p> 3087 <p id="rfc.section.1 1.17.p.5">If Content-Location is included in a response message and its value differs from the effective request URI, then the origin3082 <p id="rfc.section.10.17.p.5">If Content-Location is included in a response message and its value differs from the effective request URI, then the origin 3088 3083 server is informing recipients that this representation has its own, presumably more specific, identifier. For a GET or HEAD 3089 3084 request, this is an indication that the effective request URI identifies a resource that is subject to content negotiation … … 3094 3089 in the future. 3095 3090 </p> 3096 <p id="rfc.section.1 1.17.p.6">If Content-Location is included in a request message, then it <em class="bcp14">MAY</em> be interpreted by the origin server as an indication of where the user agent originally obtained the content of the enclosed3091 <p id="rfc.section.10.17.p.6">If Content-Location is included in a request message, then it <em class="bcp14">MAY</em> be interpreted by the origin server as an indication of where the user agent originally obtained the content of the enclosed 3097 3092 representation (prior to any subsequent modification of the content by that user agent). In other words, the user agent is 3098 3093 providing the same representation metadata that it received with the original representation. However, such interpretation <em class="bcp14">MUST NOT</em> be used to alter the semantics of the method requested by the client. For example, if a client makes a PUT request on a negotiated … … 3102 3097 latter semantics, it would have applied the PUT directly to the Content-Location URI. 3103 3098 </p> 3104 <p id="rfc.section.1 1.17.p.7">A Content-Location field received in a request message is transitory information that <em class="bcp14">SHOULD NOT</em> be saved with other representation metadata for use in later responses. The Content-Location's value might be saved for use3099 <p id="rfc.section.10.17.p.7">A Content-Location field received in a request message is transitory information that <em class="bcp14">SHOULD NOT</em> be saved with other representation metadata for use in later responses. The Content-Location's value might be saved for use 3105 3100 in other contexts, such as within source links or other metadata. 3106 3101 </p> 3107 <p id="rfc.section.1 1.17.p.8">A cache cannot assume that a representation with a Content-Location different from the URI used to retrieve it can be used3102 <p id="rfc.section.10.17.p.8">A cache cannot assume that a representation with a Content-Location different from the URI used to retrieve it can be used 3108 3103 to respond to later requests on that Content-Location URI. 3109 3104 </p> 3110 <p id="rfc.section.1 1.17.p.9">If the Content-Location value is a partial URI, the partial URI is interpreted relative to the effective request URI.</p>3105 <p id="rfc.section.10.17.p.9">If the Content-Location value is a partial URI, the partial URI is interpreted relative to the effective request URI.</p> 3111 3106 <div id="rfc.iref.c.10"></div> 3112 3107 <div id="rfc.iref.h.19"></div> 3113 <h2 id="rfc.section.1 1.18"><a href="#rfc.section.11.18">11.18</a> <a id="header.content-type" href="#header.content-type">Content-Type</a></h2>3114 <p id="rfc.section.1 1.18.p.1">The "Content-Type" header field indicates the media type of the representation. In the case of responses to the HEAD method,3108 <h2 id="rfc.section.10.18"><a href="#rfc.section.10.18">10.18</a> <a id="header.content-type" href="#header.content-type">Content-Type</a></h2> 3109 <p id="rfc.section.10.18.p.1">The "Content-Type" header field indicates the media type of the representation. In the case of responses to the HEAD method, 3115 3110 the media type is that which would have been sent had the request been a GET. 3116 3111 </p> 3117 3112 <div id="rfc.figure.u.62"></div><pre class="inline"><span id="rfc.iref.g.61"></span> <a href="#header.content-type" class="smpl">Content-Type</a> = <a href="#media.types" class="smpl">media-type</a> 3118 </pre><p id="rfc.section.1 1.18.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section 7.3</a>. An example of the field is3113 </pre><p id="rfc.section.10.18.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section 6.5</a>. An example of the field is 3119 3114 </p> 3120 3115 <div id="rfc.figure.u.63"></div><pre class="text"> Content-Type: text/html; charset=ISO-8859-4 3121 </pre><p id="rfc.section.1 1.18.p.5">Further discussion of Content-Type is provided in <a href="#representation.data" title="Representation Data">Section 9.2</a>.3122 </p> 3123 <h1 id="rfc.section.1 2"><a href="#rfc.section.12">12.</a> <a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1>3124 <h2 id="rfc.section.1 2.1"><a href="#rfc.section.12.1">12.1</a> <a id="method.registration" href="#method.registration">Method Registry</a></h2>3125 <p id="rfc.section.1 2.1.p.1">The registration procedure for HTTP request methods is defined by <a href="#method.registry" title="Method Registry">Section 2.2</a> of this document.3126 </p> 3127 <p id="rfc.section.1 2.1.p.2">The HTTP Method Registry shall be created at <<a href="http://www.iana.org/assignments/http-methods">http://www.iana.org/assignments/http-methods</a>> and be populated with the registrations below:3116 </pre><p id="rfc.section.10.18.p.5">Further discussion of Content-Type is provided in <a href="#representation.data" title="Representation Data">Section 8.2</a>. 3117 </p> 3118 <h1 id="rfc.section.11"><a href="#rfc.section.11">11.</a> <a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1> 3119 <h2 id="rfc.section.11.1"><a href="#rfc.section.11.1">11.1</a> <a id="method.registration" href="#method.registration">Method Registry</a></h2> 3120 <p id="rfc.section.11.1.p.1">The registration procedure for HTTP request methods is defined by <a href="#method.registry" title="Method Registry">Section 2.2</a> of this document. 3121 </p> 3122 <p id="rfc.section.11.1.p.2">The HTTP Method Registry shall be created at <<a href="http://www.iana.org/assignments/http-methods">http://www.iana.org/assignments/http-methods</a>> and be populated with the registrations below: 3128 3123 </p> 3129 3124 <div id="rfc.table.1"> … … 3189 3184 </table> 3190 3185 </div> 3191 <h2 id="rfc.section.1 2.2"><a href="#rfc.section.12.2">12.2</a> <a id="status.code.registration" href="#status.code.registration">Status Code Registry</a></h2>3192 <p id="rfc.section.1 2.2.p.1">The registration procedure for HTTP Status Codes — previously defined in <a href="http://tools.ietf.org/html/rfc2817#section-7.1">Section 7.1</a> of <a href="#RFC2817" id="rfc.xref.RFC2817.1"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a> — is now defined by <a href="#status.code.registry" title="Status Code Registry">Section 4.2</a> of this document.3193 </p> 3194 <p id="rfc.section.1 2.2.p.2">The HTTP Status Code Registry located at <<a href="http://www.iana.org/assignments/http-status-codes">http://www.iana.org/assignments/http-status-codes</a>> shall be updated with the registrations below:3186 <h2 id="rfc.section.11.2"><a href="#rfc.section.11.2">11.2</a> <a id="status.code.registration" href="#status.code.registration">Status Code Registry</a></h2> 3187 <p id="rfc.section.11.2.p.1">The registration procedure for HTTP Status Codes — previously defined in <a href="http://tools.ietf.org/html/rfc2817#section-7.1">Section 7.1</a> of <a href="#RFC2817" id="rfc.xref.RFC2817.1"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a> — is now defined by <a href="#status.code.registry" title="Status Code Registry">Section 4.2</a> of this document. 3188 </p> 3189 <p id="rfc.section.11.2.p.2">The HTTP Status Code Registry located at <<a href="http://www.iana.org/assignments/http-status-codes">http://www.iana.org/assignments/http-status-codes</a>> shall be updated with the registrations below: 3195 3190 </p> 3196 3191 <div id="rfc.table.2"> … … 3424 3419 </table> 3425 3420 </div> 3426 <h2 id="rfc.section.1 2.3"><a href="#rfc.section.12.3">12.3</a> <a id="header.field.registration" href="#header.field.registration">Header Field Registration</a></h2>3427 <p id="rfc.section.1 2.3.p.1">The Message Header Field Registry located at <<a href="http://www.iana.org/assignments/message-headers/message-header-index.html">http://www.iana.org/assignments/message-headers/message-header-index.html</a>> shall be updated with the permanent registrations below (see <a href="#RFC3864" id="rfc.xref.RFC3864.3"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>):3421 <h2 id="rfc.section.11.3"><a href="#rfc.section.11.3">11.3</a> <a id="header.field.registration" href="#header.field.registration">Header Field Registration</a></h2> 3422 <p id="rfc.section.11.3.p.1">The Message Header Field Registry located at <<a href="http://www.iana.org/assignments/message-headers/message-header-index.html">http://www.iana.org/assignments/message-headers/message-header-index.html</a>> shall be updated with the permanent registrations below (see <a href="#RFC3864" id="rfc.xref.RFC3864.3"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>): 3428 3423 </p> 3429 3424 <div id="rfc.table.3"> … … 3443 3438 <td class="left">http</td> 3444 3439 <td class="left">standard</td> 3445 <td class="left"> <a href="#header.accept" id="rfc.xref.header.accept.4" title="Accept">Section 1 1.11</a>3440 <td class="left"> <a href="#header.accept" id="rfc.xref.header.accept.4" title="Accept">Section 10.11</a> 3446 3441 </td> 3447 3442 </tr> … … 3450 3445 <td class="left">http</td> 3451 3446 <td class="left">standard</td> 3452 <td class="left"> <a href="#header.accept-charset" id="rfc.xref.header.accept-charset.3" title="Accept-Charset">Section 1 1.12</a>3447 <td class="left"> <a href="#header.accept-charset" id="rfc.xref.header.accept-charset.3" title="Accept-Charset">Section 10.12</a> 3453 3448 </td> 3454 3449 </tr> … … 3457 3452 <td class="left">http</td> 3458 3453 <td class="left">standard</td> 3459 <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.4" title="Accept-Encoding">Section 1 1.13</a>3454 <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.4" title="Accept-Encoding">Section 10.13</a> 3460 3455 </td> 3461 3456 </tr> … … 3464 3459 <td class="left">http</td> 3465 3460 <td class="left">standard</td> 3466 <td class="left"> <a href="#header.accept-language" id="rfc.xref.header.accept-language.3" title="Accept-Language">Section 1 1.14</a>3461 <td class="left"> <a href="#header.accept-language" id="rfc.xref.header.accept-language.3" title="Accept-Language">Section 10.14</a> 3467 3462 </td> 3468 3463 </tr> … … 3471 3466 <td class="left">http</td> 3472 3467 <td class="left">standard</td> 3473 <td class="left"> <a href="#header.allow" id="rfc.xref.header.allow.3" title="Allow">Section 1 1.1</a>3468 <td class="left"> <a href="#header.allow" id="rfc.xref.header.allow.3" title="Allow">Section 10.1</a> 3474 3469 </td> 3475 3470 </tr> … … 3478 3473 <td class="left">http</td> 3479 3474 <td class="left">standard</td> 3480 <td class="left"> <a href="#header.content-encoding" id="rfc.xref.header.content-encoding.4" title="Content-Encoding">Section 1 1.15</a>3475 <td class="left"> <a href="#header.content-encoding" id="rfc.xref.header.content-encoding.4" title="Content-Encoding">Section 10.15</a> 3481 3476 </td> 3482 3477 </tr> … … 3485 3480 <td class="left">http</td> 3486 3481 <td class="left">standard</td> 3487 <td class="left"> <a href="#header.content-language" id="rfc.xref.header.content-language.2" title="Content-Language">Section 1 1.16</a>3482 <td class="left"> <a href="#header.content-language" id="rfc.xref.header.content-language.2" title="Content-Language">Section 10.16</a> 3488 3483 </td> 3489 3484 </tr> … … 3492 3487 <td class="left">http</td> 3493 3488 <td class="left">standard</td> 3494 <td class="left"> <a href="#header.content-location" id="rfc.xref.header.content-location.4" title="Content-Location">Section 1 1.17</a>3489 <td class="left"> <a href="#header.content-location" id="rfc.xref.header.content-location.4" title="Content-Location">Section 10.17</a> 3495 3490 </td> 3496 3491 </tr> … … 3499 3494 <td class="left">http</td> 3500 3495 <td class="left">standard</td> 3501 <td class="left"> <a href="#header.content-type" id="rfc.xref.header.content-type.5" title="Content-Type">Section 1 1.18</a>3496 <td class="left"> <a href="#header.content-type" id="rfc.xref.header.content-type.5" title="Content-Type">Section 10.18</a> 3502 3497 </td> 3503 3498 </tr> … … 3506 3501 <td class="left">http</td> 3507 3502 <td class="left">standard</td> 3508 <td class="left"> <a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section 1 1.2</a>3503 <td class="left"> <a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section 10.2</a> 3509 3504 </td> 3510 3505 </tr> … … 3513 3508 <td class="left">http</td> 3514 3509 <td class="left">standard</td> 3515 <td class="left"> <a href="#header.expect" id="rfc.xref.header.expect.3" title="Expect">Section 1 1.3</a>3510 <td class="left"> <a href="#header.expect" id="rfc.xref.header.expect.3" title="Expect">Section 10.3</a> 3516 3511 </td> 3517 3512 </tr> … … 3520 3515 <td class="left">http</td> 3521 3516 <td class="left">standard</td> 3522 <td class="left"> <a href="#header.from" id="rfc.xref.header.from.2" title="From">Section 1 1.4</a>3517 <td class="left"> <a href="#header.from" id="rfc.xref.header.from.2" title="From">Section 10.4</a> 3523 3518 </td> 3524 3519 </tr> … … 3527 3522 <td class="left">http</td> 3528 3523 <td class="left">standard</td> 3529 <td class="left"> <a href="#header.location" id="rfc.xref.header.location.4" title="Location">Section 1 1.5</a>3524 <td class="left"> <a href="#header.location" id="rfc.xref.header.location.4" title="Location">Section 10.5</a> 3530 3525 </td> 3531 3526 </tr> … … 3541 3536 <td class="left">http</td> 3542 3537 <td class="left">standard</td> 3543 <td class="left"> <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.4" title="Max-Forwards">Section 1 1.6</a>3538 <td class="left"> <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.4" title="Max-Forwards">Section 10.6</a> 3544 3539 </td> 3545 3540 </tr> … … 3548 3543 <td class="left">http</td> 3549 3544 <td class="left">standard</td> 3550 <td class="left"> <a href="#header.referer" id="rfc.xref.header.referer.2" title="Referer">Section 1 1.7</a>3545 <td class="left"> <a href="#header.referer" id="rfc.xref.header.referer.2" title="Referer">Section 10.7</a> 3551 3546 </td> 3552 3547 </tr> … … 3555 3550 <td class="left">http</td> 3556 3551 <td class="left">standard</td> 3557 <td class="left"> <a href="#header.retry-after" id="rfc.xref.header.retry-after.3" title="Retry-After">Section 1 1.8</a>3552 <td class="left"> <a href="#header.retry-after" id="rfc.xref.header.retry-after.3" title="Retry-After">Section 10.8</a> 3558 3553 </td> 3559 3554 </tr> … … 3562 3557 <td class="left">http</td> 3563 3558 <td class="left">standard</td> 3564 <td class="left"> <a href="#header.server" id="rfc.xref.header.server.2" title="Server">Section 1 1.9</a>3559 <td class="left"> <a href="#header.server" id="rfc.xref.header.server.2" title="Server">Section 10.9</a> 3565 3560 </td> 3566 3561 </tr> … … 3569 3564 <td class="left">http</td> 3570 3565 <td class="left">standard</td> 3571 <td class="left"> <a href="#header.user-agent" id="rfc.xref.header.user-agent.3" title="User-Agent">Section 1 1.10</a>3566 <td class="left"> <a href="#header.user-agent" id="rfc.xref.header.user-agent.3" title="User-Agent">Section 10.10</a> 3572 3567 </td> 3573 3568 </tr> … … 3575 3570 </table> 3576 3571 </div> 3577 <p id="rfc.section.1 2.3.p.2">The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>3578 <h2 id="rfc.section.1 2.4"><a href="#rfc.section.12.4">12.4</a> <a id="content.coding.registration" href="#content.coding.registration">Content Coding Registry</a></h2>3579 <p id="rfc.section.1 2.4.p.1">The registration procedure for HTTP Content Codings is now defined by <a href="#content.coding.registry" title="Content Coding Registry">Section 7.2.1</a> of this document.3580 </p> 3581 <p id="rfc.section.1 2.4.p.2">The HTTP Content Codings Registry located at <<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>> shall be updated with the registration below:3572 <p id="rfc.section.11.3.p.2">The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p> 3573 <h2 id="rfc.section.11.4"><a href="#rfc.section.11.4">11.4</a> <a id="content.coding.registration" href="#content.coding.registration">Content Coding Registry</a></h2> 3574 <p id="rfc.section.11.4.p.1">The registration procedure for HTTP Content Codings is now defined by <a href="#content.coding.registry" title="Content Coding Registry">Section 6.4.1</a> of this document. 3575 </p> 3576 <p id="rfc.section.11.4.p.2">The HTTP Content Codings Registry located at <<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>> shall be updated with the registration below: 3582 3577 </p> 3583 3578 <div id="rfc.table.4"> … … 3614 3609 <td class="left">identity</td> 3615 3610 <td class="left">reserved (synonym for "no encoding" in Accept-Encoding header field)</td> 3616 <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.5" title="Accept-Encoding">Section 1 1.13</a>3611 <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.5" title="Accept-Encoding">Section 10.13</a> 3617 3612 </td> 3618 3613 </tr> … … 3620 3615 </table> 3621 3616 </div> 3622 <h1 id="rfc.section.1 3"><a href="#rfc.section.13">13.</a> <a id="security.considerations" href="#security.considerations">Security Considerations</a></h1>3623 <p id="rfc.section.1 3.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.13617 <h1 id="rfc.section.12"><a href="#rfc.section.12">12.</a> <a id="security.considerations" href="#security.considerations">Security Considerations</a></h1> 3618 <p id="rfc.section.12.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.1 3624 3619 as described by this document. The discussion does not include definitive solutions to the problems revealed, though it does 3625 3620 make some suggestions for reducing security risks. 3626 3621 </p> 3627 <h2 id="rfc.section.1 3.1"><a href="#rfc.section.13.1">13.1</a> <a id="security.sensitive" href="#security.sensitive">Transfer of Sensitive Information</a></h2>3628 <p id="rfc.section.1 3.1.p.1">Like any generic data transfer protocol, HTTP cannot regulate the content of the data that is transferred, nor is there any3622 <h2 id="rfc.section.12.1"><a href="#rfc.section.12.1">12.1</a> <a id="security.sensitive" href="#security.sensitive">Transfer of Sensitive Information</a></h2> 3623 <p id="rfc.section.12.1.p.1">Like any generic data transfer protocol, HTTP cannot regulate the content of the data that is transferred, nor is there any 3629 3624 a priori method of determining the sensitivity of any particular piece of information within the context of any given request. 3630 3625 Therefore, applications <em class="bcp14">SHOULD</em> supply as much control over this information as possible to the provider of that information. Four header fields are worth 3631 3626 special mention in this context: Server, Via, Referer and From. 3632 3627 </p> 3633 <p id="rfc.section.1 3.1.p.2">Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks3628 <p id="rfc.section.12.1.p.2">Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks 3634 3629 against software that is known to contain security holes. Implementors <em class="bcp14">SHOULD</em> make the Server header field a configurable option. 3635 3630 </p> 3636 <p id="rfc.section.1 3.1.p.3">Proxies which serve as a portal through a network firewall <em class="bcp14">SHOULD</em> take special precautions regarding the transfer of header information that identifies the hosts behind the firewall. In particular,3631 <p id="rfc.section.12.1.p.3">Proxies which serve as a portal through a network firewall <em class="bcp14">SHOULD</em> take special precautions regarding the transfer of header information that identifies the hosts behind the firewall. In particular, 3637 3632 they <em class="bcp14">SHOULD</em> remove, or replace with sanitized versions, any Via fields generated behind the firewall. 3638 3633 </p> 3639 <p id="rfc.section.1 3.1.p.4">The Referer header field allows reading patterns to be studied and reverse links drawn. Although it can be very useful, its3634 <p id="rfc.section.12.1.p.4">The Referer header field allows reading patterns to be studied and reverse links drawn. Although it can be very useful, its 3640 3635 power can be abused if user details are not separated from the information contained in the Referer. Even when the personal 3641 3636 information has been removed, the Referer header field might indicate a private document's URI whose publication would be 3642 3637 inappropriate. 3643 3638 </p> 3644 <p id="rfc.section.1 3.1.p.5">The information sent in the From field might conflict with the user's privacy interests or their site's security policy, and3639 <p id="rfc.section.12.1.p.5">The information sent in the From field might conflict with the user's privacy interests or their site's security policy, and 3645 3640 hence it <em class="bcp14">SHOULD NOT</em> be transmitted without the user being able to disable, enable, and modify the contents of the field. The user <em class="bcp14">MUST</em> be able to set the contents of this field within a user preference or application defaults configuration. 3646 3641 </p> 3647 <p id="rfc.section.1 3.1.p.6">We suggest, though do not require, that a convenient toggle interface be provided for the user to enable or disable the sending3642 <p id="rfc.section.12.1.p.6">We suggest, though do not require, that a convenient toggle interface be provided for the user to enable or disable the sending 3648 3643 of From and Referer information. 3649 3644 </p> 3650 <p id="rfc.section.1 3.1.p.7">The User-Agent (<a href="#header.user-agent" id="rfc.xref.header.user-agent.4" title="User-Agent">Section 11.10</a>) or Server (<a href="#header.server" id="rfc.xref.header.server.3" title="Server">Section 11.9</a>) header fields can sometimes be used to determine that a specific client or server has a particular security hole which might3645 <p id="rfc.section.12.1.p.7">The User-Agent (<a href="#header.user-agent" id="rfc.xref.header.user-agent.4" title="User-Agent">Section 10.10</a>) or Server (<a href="#header.server" id="rfc.xref.header.server.3" title="Server">Section 10.9</a>) header fields can sometimes be used to determine that a specific client or server has a particular security hole which might 3651 3646 be exploited. Unfortunately, this same information is often used for other valuable purposes for which HTTP currently has 3652 3647 no better mechanism. 3653 3648 </p> 3654 <p id="rfc.section.1 3.1.p.8">Furthermore, the User-Agent header field may contain enough entropy to be used, possibly in conjunction with other material,3649 <p id="rfc.section.12.1.p.8">Furthermore, the User-Agent header field may contain enough entropy to be used, possibly in conjunction with other material, 3655 3650 to uniquely identify the user. 3656 3651 </p> 3657 <p id="rfc.section.1 3.1.p.9">Some request methods, like TRACE (<a href="#TRACE" id="rfc.xref.TRACE.3" title="TRACE">Section 2.3.7</a>), expose information that was sent in request header fields within the body of their response. Clients <em class="bcp14">SHOULD</em> be careful with sensitive information, like Cookies, Authorization credentials, and other header fields that might be used3652 <p id="rfc.section.12.1.p.9">Some request methods, like TRACE (<a href="#TRACE" id="rfc.xref.TRACE.3" title="TRACE">Section 2.3.7</a>), expose information that was sent in request header fields within the body of their response. Clients <em class="bcp14">SHOULD</em> be careful with sensitive information, like Cookies, Authorization credentials, and other header fields that might be used 3658 3653 to collect data from the client. 3659 3654 </p> 3660 <h2 id="rfc.section.1 3.2"><a href="#rfc.section.13.2">13.2</a> <a id="encoding.sensitive.information.in.uris" href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></h2>3661 <p id="rfc.section.1 3.2.p.1">Because the source of a link might be private information or might reveal an otherwise private information source, it is strongly3655 <h2 id="rfc.section.12.2"><a href="#rfc.section.12.2">12.2</a> <a id="encoding.sensitive.information.in.uris" href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></h2> 3656 <p id="rfc.section.12.2.p.1">Because the source of a link might be private information or might reveal an otherwise private information source, it is strongly 3662 3657 recommended that the user be able to select whether or not the Referer field is sent. For example, a browser client could 3663 3658 have a toggle switch for browsing openly/anonymously, which would respectively enable/disable the sending of Referer and From 3664 3659 information. 3665 3660 </p> 3666 <p id="rfc.section.1 3.2.p.2">Clients <em class="bcp14">SHOULD NOT</em> include a Referer header field in a (non-secure) HTTP request if the referring page was transferred with a secure protocol.3667 </p> 3668 <p id="rfc.section.1 3.2.p.3">Authors of services <em class="bcp14">SHOULD NOT</em> use GET-based forms for the submission of sensitive data because that data will be placed in the request-target. Many existing3661 <p id="rfc.section.12.2.p.2">Clients <em class="bcp14">SHOULD NOT</em> include a Referer header field in a (non-secure) HTTP request if the referring page was transferred with a secure protocol. 3662 </p> 3663 <p id="rfc.section.12.2.p.3">Authors of services <em class="bcp14">SHOULD NOT</em> use GET-based forms for the submission of sensitive data because that data will be placed in the request-target. Many existing 3669 3664 servers, proxies, and user agents log or display the request-target in places where it might be visible to third parties. 3670 3665 Such services can use POST-based form submission instead. 3671 3666 </p> 3672 <h2 id="rfc.section.1 3.3"><a href="#rfc.section.13.3">13.3</a> <a id="location.spoofing-leakage" href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></h2>3673 <p id="rfc.section.1 3.3.p.1">If a single server supports multiple organizations that do not trust one another, then it <em class="bcp14">MUST</em> check the values of Location and Content-Location header fields in responses that are generated under control of said organizations3667 <h2 id="rfc.section.12.3"><a href="#rfc.section.12.3">12.3</a> <a id="location.spoofing-leakage" href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></h2> 3668 <p id="rfc.section.12.3.p.1">If a single server supports multiple organizations that do not trust one another, then it <em class="bcp14">MUST</em> check the values of Location and Content-Location header fields in responses that are generated under control of said organizations 3674 3669 to make sure that they do not attempt to invalidate resources over which they have no authority. 3675 3670 </p> 3676 <p id="rfc.section.1 3.3.p.2">Furthermore, appending the fragment identifier from one URI to another one obtained from a Location header field might leak3671 <p id="rfc.section.12.3.p.2">Furthermore, appending the fragment identifier from one URI to another one obtained from a Location header field might leak 3677 3672 confidential information to the target server — although the fragment identifier is not transmitted in the final request, 3678 3673 it might be visible to the user agent through other means, such as scripting. 3679 3674 </p> 3680 <h2 id="rfc.section.1 3.4"><a href="#rfc.section.13.4">13.4</a> Security Considerations for CONNECT3675 <h2 id="rfc.section.12.4"><a href="#rfc.section.12.4">12.4</a> Security Considerations for CONNECT 3681 3676 </h2> 3682 <p id="rfc.section.1 3.4.p.1">Since tunneled data is opaque to the proxy, there are additional risks to tunneling to other well-known or reserved ports.3677 <p id="rfc.section.12.4.p.1">Since tunneled data is opaque to the proxy, there are additional risks to tunneling to other well-known or reserved ports. 3683 3678 A HTTP client CONNECTing to port 25 could relay spam via SMTP, for example. As such, proxies <em class="bcp14">SHOULD</em> restrict CONNECT access to a small number of known ports. 3684 3679 </p> 3685 <h2 id="rfc.section.1 3.5"><a href="#rfc.section.13.5">13.5</a> <a id="privacy.issues.connected.to.accept.header.fields" href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></h2>3686 <p id="rfc.section.1 3.5.p.1">Accept header fields can reveal information about the user to all servers which are accessed. The Accept-Language header field3680 <h2 id="rfc.section.12.5"><a href="#rfc.section.12.5">12.5</a> <a id="privacy.issues.connected.to.accept.header.fields" href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></h2> 3681 <p id="rfc.section.12.5.p.1">Accept header fields can reveal information about the user to all servers which are accessed. The Accept-Language header field 3687 3682 in particular can reveal information the user would consider to be of a private nature, because the understanding of particular 3688 3683 languages is often strongly correlated to the membership of a particular ethnic group. User agents which offer the option … … 3690 3685 configuration process include a message which makes the user aware of the loss of privacy involved. 3691 3686 </p> 3692 <p id="rfc.section.1 3.5.p.2">An approach that limits the loss of privacy would be for a user agent to omit the sending of Accept-Language header fields3687 <p id="rfc.section.12.5.p.2">An approach that limits the loss of privacy would be for a user agent to omit the sending of Accept-Language header fields 3693 3688 by default, and to ask the user whether or not to start sending Accept-Language header fields to a server if it detects, by 3694 3689 looking for any Vary header fields generated by the server, that such sending could improve the quality of service. 3695 3690 </p> 3696 <p id="rfc.section.1 3.5.p.3">Elaborate user-customized accept header fields sent in every request, in particular if these include quality values, can be3691 <p id="rfc.section.12.5.p.3">Elaborate user-customized accept header fields sent in every request, in particular if these include quality values, can be 3697 3692 used by servers as relatively reliable and long-lived user identifiers. Such user identifiers would allow content providers 3698 3693 to do click-trail tracking, and would allow collaborating content providers to match cross-server click-trails or form submissions … … 3702 3697 filter the accept header fields in relayed requests. General purpose user agents which provide a high degree of header configurability <em class="bcp14">SHOULD</em> warn users about the loss of privacy which can be involved. 3703 3698 </p> 3704 <h1 id="rfc.section.1 4"><a href="#rfc.section.14">14.</a> <a id="acks" href="#acks">Acknowledgments</a></h1>3705 <p id="rfc.section.1 4.p.1">See <a href="p1-messaging.html#acks" title="Acknowledgments">Section 9</a> of <a href="#Part1" id="rfc.xref.Part1.53"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>.3706 </p> 3707 <h1 id="rfc.references"><a id="rfc.section.1 5" href="#rfc.section.15">15.</a> References3699 <h1 id="rfc.section.13"><a href="#rfc.section.13">13.</a> <a id="acks" href="#acks">Acknowledgments</a></h1> 3700 <p id="rfc.section.13.p.1">See <a href="p1-messaging.html#acks" title="Acknowledgments">Section 9</a> of <a href="#Part1" id="rfc.xref.Part1.53"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. 3701 </p> 3702 <h1 id="rfc.references"><a id="rfc.section.14" href="#rfc.section.14">14.</a> References 3708 3703 </h1> 3709 <h2 id="rfc.references.1"><a href="#rfc.section.1 5.1" id="rfc.section.15.1">15.1</a> Normative References3704 <h2 id="rfc.references.1"><a href="#rfc.section.14.1" id="rfc.section.14.1">14.1</a> Normative References 3710 3705 </h2> 3711 3706 <table> … … 3796 3791 </tr> 3797 3792 </table> 3798 <h2 id="rfc.references.2"><a href="#rfc.section.1 5.2" id="rfc.section.15.2">15.2</a> Informative References3793 <h2 id="rfc.references.2"><a href="#rfc.section.14.2" id="rfc.section.14.2">14.2</a> Informative References 3799 3794 </h2> 3800 3795 <table> … … 3929 3924 </p> 3930 3925 <h2 id="rfc.section.A.2"><a href="#rfc.section.A.2">A.2</a> <a id="conversion.to.canonical.form" href="#conversion.to.canonical.form">Conversion to Canonical Form</a></h2> 3931 <p id="rfc.section.A.2.p.1">MIME requires that an Internet mail body-part be converted to canonical form prior to being transferred, as described in <a href="http://tools.ietf.org/html/rfc2049#section-4">Section 4</a> of <a href="#RFC2049" id="rfc.xref.RFC2049.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples">[RFC2049]</cite></a>. <a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 7.3.1</a> of this document describes the forms allowed for subtypes of the "text" media type when transmitted over HTTP. <a href="#RFC2046" id="rfc.xref.RFC2046.4"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> requires that content with a type of "text" represent line breaks as CRLF and forbids the use of CR or LF outside of line3926 <p id="rfc.section.A.2.p.1">MIME requires that an Internet mail body-part be converted to canonical form prior to being transferred, as described in <a href="http://tools.ietf.org/html/rfc2049#section-4">Section 4</a> of <a href="#RFC2049" id="rfc.xref.RFC2049.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples">[RFC2049]</cite></a>. <a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 6.5.1</a> of this document describes the forms allowed for subtypes of the "text" media type when transmitted over HTTP. <a href="#RFC2046" id="rfc.xref.RFC2046.4"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> requires that content with a type of "text" represent line breaks as CRLF and forbids the use of CR or LF outside of line 3932 3927 break sequences. HTTP allows CRLF, bare CR, and bare LF to indicate a line break within text content when a message is transmitted 3933 3928 over HTTP. 3934 3929 </p> 3935 <p id="rfc.section.A.2.p.2">Where it is possible, a proxy or gateway from HTTP to a strict MIME environment <em class="bcp14">SHOULD</em> translate all line breaks within the text media types described in <a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 7.3.1</a> of this document to the RFC 2049 canonical form of CRLF. Note, however, that this might be complicated by the presence of3930 <p id="rfc.section.A.2.p.2">Where it is possible, a proxy or gateway from HTTP to a strict MIME environment <em class="bcp14">SHOULD</em> translate all line breaks within the text media types described in <a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 6.5.1</a> of this document to the RFC 2049 canonical form of CRLF. Note, however, that this might be complicated by the presence of 3936 3931 a Content-Encoding and by the fact that HTTP allows the use of some character encodings which do not use octets 13 and 10 3937 3932 to represent CR and LF, respectively, as is the case for some multi-byte character encodings. … … 3965 3960 <p id="rfc.section.A.7.p.1">HTTP implementations which share code with MHTML <a href="#RFC2557" id="rfc.xref.RFC2557.2"><cite title="MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)">[RFC2557]</cite></a> implementations need to be aware of MIME line length limitations. Since HTTP does not have this limitation, HTTP does not 3966 3961 fold long lines. MHTML messages being transported by HTTP follow all conventions of MHTML, including line length limitations 3967 and folding, canonicalization, etc., since HTTP transports all message-bodies as payload (see <a href="#multipart.types" title="Multipart Types">Section 7.3.2</a>) and does not interpret the content or any MIME header lines that might be contained therein.3962 and folding, canonicalization, etc., since HTTP transports all message-bodies as payload (see <a href="#multipart.types" title="Multipart Types">Section 6.5.2</a>) and does not interpret the content or any MIME header lines that might be contained therein. 3968 3963 </p> 3969 3964 <h1 id="rfc.section.B"><a href="#rfc.section.B">B.</a> <a id="additional.features" href="#additional.features">Additional Features</a></h1> … … 3998 3993 <p id="rfc.section.C.p.9">Define status 426 (Upgrade Required) (this was incorporated from <a href="#RFC2817" id="rfc.xref.RFC2817.4"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>). (<a href="#status.426" id="rfc.xref.status.426.3" title="426 Upgrade Required">Section 4.6.15</a>) 3999 3994 </p> 4000 <p id="rfc.section.C.p.10">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section 1 1</a>)3995 <p id="rfc.section.C.p.10">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section 10</a>) 4001 3996 </p> 4002 3997 <p id="rfc.section.C.p.11">Reclassify "Allow" as response header field, removing the option to specify it in a PUT request. Relax the server requirement 4003 on the contents of the Allow header field and remove requirement on clients to always trust the header field value. (<a href="#header.allow" id="rfc.xref.header.allow.4" title="Allow">Section 1 1.1</a>)3998 on the contents of the Allow header field and remove requirement on clients to always trust the header field value. (<a href="#header.allow" id="rfc.xref.header.allow.4" title="Allow">Section 10.1</a>) 4004 3999 </p> 4005 4000 <p id="rfc.section.C.p.12">The ABNF for the Expect header field has been both fixed (allowing parameters for value-less expectations as well) and simplified 4006 (allowing trailing semicolons after "100-continue" when they were invalid before). (<a href="#header.expect" id="rfc.xref.header.expect.4" title="Expect">Section 1 1.3</a>)4001 (allowing trailing semicolons after "100-continue" when they were invalid before). (<a href="#header.expect" id="rfc.xref.header.expect.4" title="Expect">Section 10.3</a>) 4007 4002 </p> 4008 4003 <p id="rfc.section.C.p.13">Correct syntax of Location header field to allow URI references (including relative references and fragments), as referred 4009 4004 symbol "absoluteURI" wasn't what was expected, and add some clarifications as to when use of fragments would not be appropriate. 4010 (<a href="#header.location" id="rfc.xref.header.location.5" title="Location">Section 1 1.5</a>)4011 </p> 4012 <p id="rfc.section.C.p.14">Restrict Max-Forwards header field to OPTIONS and TRACE (previously, extension methods could have used it as well). (<a href="#header.max-forwards" id="rfc.xref.header.max-forwards.5" title="Max-Forwards">Section 1 1.6</a>)4013 </p> 4014 <p id="rfc.section.C.p.15">Allow Referer field value of "about:blank" as alternative to not specifying it. (<a href="#header.referer" id="rfc.xref.header.referer.3" title="Referer">Section 1 1.7</a>)4005 (<a href="#header.location" id="rfc.xref.header.location.5" title="Location">Section 10.5</a>) 4006 </p> 4007 <p id="rfc.section.C.p.14">Restrict Max-Forwards header field to OPTIONS and TRACE (previously, extension methods could have used it as well). (<a href="#header.max-forwards" id="rfc.xref.header.max-forwards.5" title="Max-Forwards">Section 10.6</a>) 4008 </p> 4009 <p id="rfc.section.C.p.15">Allow Referer field value of "about:blank" as alternative to not specifying it. (<a href="#header.referer" id="rfc.xref.header.referer.3" title="Referer">Section 10.7</a>) 4015 4010 </p> 4016 4011 <p id="rfc.section.C.p.16">In the description of the Server header field, the Via field was described as a SHOULD. The requirement was and is stated 4017 correctly in the description of the Via header field in <a href="p1-messaging.html#header.via" title="Via">Section 6.2</a> of <a href="#Part1" id="rfc.xref.Part1.55"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. (<a href="#header.server" id="rfc.xref.header.server.4" title="Server">Section 1 1.9</a>)4018 </p> 4019 <p id="rfc.section.C.p.17">Clarify contexts that charset is used in. (<a href="#character.sets" title="Character Encodings (charset)">Section 7.1</a>)4020 </p> 4021 <p id="rfc.section.C.p.18">Registration of Content Codings now requires IETF Review (<a href="#content.coding.registry" title="Content Coding Registry">Section 7.2.1</a>)4022 </p> 4023 <p id="rfc.section.C.p.19">Remove the default character encoding for text media types; the default now is whatever the media type definition says. (<a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 7.3.1</a>)4024 </p> 4025 <p id="rfc.section.C.p.20">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section 1 1</a>)4012 correctly in the description of the Via header field in <a href="p1-messaging.html#header.via" title="Via">Section 6.2</a> of <a href="#Part1" id="rfc.xref.Part1.55"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. (<a href="#header.server" id="rfc.xref.header.server.4" title="Server">Section 10.9</a>) 4013 </p> 4014 <p id="rfc.section.C.p.17">Clarify contexts that charset is used in. (<a href="#character.sets" title="Character Encodings (charset)">Section 6.3</a>) 4015 </p> 4016 <p id="rfc.section.C.p.18">Registration of Content Codings now requires IETF Review (<a href="#content.coding.registry" title="Content Coding Registry">Section 6.4.1</a>) 4017 </p> 4018 <p id="rfc.section.C.p.19">Remove the default character encoding for text media types; the default now is whatever the media type definition says. (<a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 6.5.1</a>) 4019 </p> 4020 <p id="rfc.section.C.p.20">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section 10</a>) 4026 4021 </p> 4027 4022 <p id="rfc.section.C.p.21">Remove definition of Content-MD5 header field because it was inconsistently implemented with respect to partial responses, 4028 and also because of known deficiencies in the hash algorithm itself (see <a href="#RFC6151" id="rfc.xref.RFC6151.1"><cite title="Updated Security Considerations for the MD5 Message-Digest and the HMAC-MD5 Algorithms">[RFC6151]</cite></a> for details). (<a href="#header.field.definitions" title="Header Field Definitions">Section 1 1</a>)4029 </p> 4030 <p id="rfc.section.C.p.22">Remove ISO-8859-1 special-casing in Accept-Charset. (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.4" title="Accept-Charset">Section 1 1.12</a>)4023 and also because of known deficiencies in the hash algorithm itself (see <a href="#RFC6151" id="rfc.xref.RFC6151.1"><cite title="Updated Security Considerations for the MD5 Message-Digest and the HMAC-MD5 Algorithms">[RFC6151]</cite></a> for details). (<a href="#header.field.definitions" title="Header Field Definitions">Section 10</a>) 4024 </p> 4025 <p id="rfc.section.C.p.22">Remove ISO-8859-1 special-casing in Accept-Charset. (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.4" title="Accept-Charset">Section 10.12</a>) 4031 4026 </p> 4032 4027 <p id="rfc.section.C.p.23">Remove base URI setting semantics for Content-Location due to poor implementation support, which was caused by too many broken 4033 4028 servers emitting bogus Content-Location header fields, and also the potentially undesirable effect of potentially breaking 4034 relative links in content-negotiated resources. (<a href="#header.content-location" id="rfc.xref.header.content-location.5" title="Content-Location">Section 1 1.17</a>)4029 relative links in content-negotiated resources. (<a href="#header.content-location" id="rfc.xref.header.content-location.5" title="Content-Location">Section 10.17</a>) 4035 4030 </p> 4036 4031 <p id="rfc.section.C.p.24">Remove reference to non-existant identity transfer-coding value tokens. (<a href="#no.content-transfer-encoding" id="rfc.xref.no.content-transfer-encoding.1" title="No Content-Transfer-Encoding">Appendix A.5</a>) … … 4778 4773 <ul class="ind"> 4779 4774 <li><a id="rfc.index.1" href="#rfc.index.1"><b>1</b></a><ul> 4780 <li>100 Continue (status code) <a href="#rfc.xref.status.100.1">4.1</a>, <a href="#rfc.iref.24"><b>4.3.1</b></a>, <a href="#rfc.xref.status.100.2">1 2.2</a></li>4781 <li>100-continue (expect value) <a href="#rfc.iref.108"><b>1 1.3</b></a></li>4782 <li>101 Switching Protocols (status code) <a href="#rfc.xref.status.101.1">4.1</a>, <a href="#rfc.iref.25"><b>4.3.2</b></a>, <a href="#rfc.xref.status.101.2">1 2.2</a></li>4775 <li>100 Continue (status code) <a href="#rfc.xref.status.100.1">4.1</a>, <a href="#rfc.iref.24"><b>4.3.1</b></a>, <a href="#rfc.xref.status.100.2">11.2</a></li> 4776 <li>100-continue (expect value) <a href="#rfc.iref.108"><b>10.3</b></a></li> 4777 <li>101 Switching Protocols (status code) <a href="#rfc.xref.status.101.1">4.1</a>, <a href="#rfc.iref.25"><b>4.3.2</b></a>, <a href="#rfc.xref.status.101.2">11.2</a></li> 4783 4778 </ul> 4784 4779 </li> 4785 4780 <li><a id="rfc.index.2" href="#rfc.index.2"><b>2</b></a><ul> 4786 <li>200 OK (status code) <a href="#rfc.xref.status.200.1">4.1</a>, <a href="#rfc.iref.26"><b>4.4.1</b></a>, <a href="#rfc.xref.status.200.2">1 2.2</a></li>4787 <li>201 Created (status code) <a href="#rfc.xref.status.201.1">4.1</a>, <a href="#rfc.iref.27"><b>4.4.2</b></a>, <a href="#rfc.xref.status.201.2">1 2.2</a></li>4788 <li>202 Accepted (status code) <a href="#rfc.xref.status.202.1">4.1</a>, <a href="#rfc.iref.28"><b>4.4.3</b></a>, <a href="#rfc.xref.status.202.2">1 2.2</a></li>4789 <li>203 Non-Authoritative Information (status code) <a href="#rfc.xref.status.203.1">4.1</a>, <a href="#rfc.iref.29"><b>4.4.4</b></a>, <a href="#rfc.xref.status.203.2">1 2.2</a>, <a href="#rfc.xref.status.203.3">C</a></li>4790 <li>204 No Content (status code) <a href="#rfc.xref.status.204.1">4.1</a>, <a href="#rfc.iref.30"><b>4.4.5</b></a>, <a href="#rfc.xref.status.204.2">1 2.2</a></li>4791 <li>205 Reset Content (status code) <a href="#rfc.xref.status.205.1">4.1</a>, <a href="#rfc.iref.31"><b>4.4.6</b></a>, <a href="#rfc.xref.status.205.2">1 2.2</a></li>4781 <li>200 OK (status code) <a href="#rfc.xref.status.200.1">4.1</a>, <a href="#rfc.iref.26"><b>4.4.1</b></a>, <a href="#rfc.xref.status.200.2">11.2</a></li> 4782 <li>201 Created (status code) <a href="#rfc.xref.status.201.1">4.1</a>, <a href="#rfc.iref.27"><b>4.4.2</b></a>, <a href="#rfc.xref.status.201.2">11.2</a></li> 4783 <li>202 Accepted (status code) <a href="#rfc.xref.status.202.1">4.1</a>, <a href="#rfc.iref.28"><b>4.4.3</b></a>, <a href="#rfc.xref.status.202.2">11.2</a></li> 4784 <li>203 Non-Authoritative Information (status code) <a href="#rfc.xref.status.203.1">4.1</a>, <a href="#rfc.iref.29"><b>4.4.4</b></a>, <a href="#rfc.xref.status.203.2">11.2</a>, <a href="#rfc.xref.status.203.3">C</a></li> 4785 <li>204 No Content (status code) <a href="#rfc.xref.status.204.1">4.1</a>, <a href="#rfc.iref.30"><b>4.4.5</b></a>, <a href="#rfc.xref.status.204.2">11.2</a></li> 4786 <li>205 Reset Content (status code) <a href="#rfc.xref.status.205.1">4.1</a>, <a href="#rfc.iref.31"><b>4.4.6</b></a>, <a href="#rfc.xref.status.205.2">11.2</a></li> 4792 4787 </ul> 4793 4788 </li> 4794 4789 <li><a id="rfc.index.3" href="#rfc.index.3"><b>3</b></a><ul> 4795 <li>300 Multiple Choices (status code) <a href="#rfc.xref.status.300.1">4.1</a>, <a href="#rfc.iref.32"><b>4.5.1</b></a>, <a href="#rfc.xref.status.300.2">1 2.2</a></li>4796 <li>301 Moved Permanently (status code) <a href="#rfc.xref.status.301.1">4.1</a>, <a href="#rfc.iref.33"><b>4.5.2</b></a>, <a href="#rfc.xref.status.301.2">1 2.2</a>, <a href="#rfc.xref.status.301.3">C</a></li>4797 <li>302 Found (status code) <a href="#rfc.xref.status.302.1">4.1</a>, <a href="#rfc.iref.34"><b>4.5.3</b></a>, <a href="#rfc.xref.status.302.2">1 2.2</a>, <a href="#rfc.xref.status.302.3">C</a></li>4798 <li>303 See Other (status code) <a href="#rfc.xref.status.303.1">4.1</a>, <a href="#rfc.iref.35"><b>4.5.4</b></a>, <a href="#rfc.xref.status.303.2">1 2.2</a></li>4799 <li>305 Use Proxy (status code) <a href="#rfc.xref.status.305.1">4.1</a>, <a href="#rfc.iref.36"><b>4.5.5</b></a>, <a href="#rfc.xref.status.305.2">1 2.2</a>, <a href="#rfc.xref.status.305.3">C</a></li>4800 <li>306 (Unused) (status code) <a href="#rfc.iref.37"><b>4.5.6</b></a>, <a href="#rfc.xref.status.306.1">1 2.2</a></li>4801 <li>307 Temporary Redirect (status code) <a href="#rfc.xref.status.307.1">4.1</a>, <a href="#rfc.iref.38"><b>4.5.7</b></a>, <a href="#rfc.xref.status.307.2">1 2.2</a>, <a href="#rfc.xref.status.307.3">C</a></li>4790 <li>300 Multiple Choices (status code) <a href="#rfc.xref.status.300.1">4.1</a>, <a href="#rfc.iref.32"><b>4.5.1</b></a>, <a href="#rfc.xref.status.300.2">11.2</a></li> 4791 <li>301 Moved Permanently (status code) <a href="#rfc.xref.status.301.1">4.1</a>, <a href="#rfc.iref.33"><b>4.5.2</b></a>, <a href="#rfc.xref.status.301.2">11.2</a>, <a href="#rfc.xref.status.301.3">C</a></li> 4792 <li>302 Found (status code) <a href="#rfc.xref.status.302.1">4.1</a>, <a href="#rfc.iref.34"><b>4.5.3</b></a>, <a href="#rfc.xref.status.302.2">11.2</a>, <a href="#rfc.xref.status.302.3">C</a></li> 4793 <li>303 See Other (status code) <a href="#rfc.xref.status.303.1">4.1</a>, <a href="#rfc.iref.35"><b>4.5.4</b></a>, <a href="#rfc.xref.status.303.2">11.2</a></li> 4794 <li>305 Use Proxy (status code) <a href="#rfc.xref.status.305.1">4.1</a>, <a href="#rfc.iref.36"><b>4.5.5</b></a>, <a href="#rfc.xref.status.305.2">11.2</a>, <a href="#rfc.xref.status.305.3">C</a></li> 4795 <li>306 (Unused) (status code) <a href="#rfc.iref.37"><b>4.5.6</b></a>, <a href="#rfc.xref.status.306.1">11.2</a></li> 4796 <li>307 Temporary Redirect (status code) <a href="#rfc.xref.status.307.1">4.1</a>, <a href="#rfc.iref.38"><b>4.5.7</b></a>, <a href="#rfc.xref.status.307.2">11.2</a>, <a href="#rfc.xref.status.307.3">C</a></li> 4802 4797 </ul> 4803 4798 </li> 4804 4799 <li><a id="rfc.index.4" href="#rfc.index.4"><b>4</b></a><ul> 4805 <li>400 Bad Request (status code) <a href="#rfc.xref.status.400.1">4.1</a>, <a href="#rfc.iref.39"><b>4.6.1</b></a>, <a href="#rfc.xref.status.400.2">1 2.2</a></li>4806 <li>402 Payment Required (status code) <a href="#rfc.xref.status.402.1">4.1</a>, <a href="#rfc.iref.40"><b>4.6.2</b></a>, <a href="#rfc.xref.status.402.2">1 2.2</a></li>4807 <li>403 Forbidden (status code) <a href="#rfc.xref.status.403.1">4.1</a>, <a href="#rfc.iref.41"><b>4.6.3</b></a>, <a href="#rfc.xref.status.403.2">1 2.2</a></li>4808 <li>404 Not Found (status code) <a href="#rfc.xref.status.404.1">4.1</a>, <a href="#rfc.iref.42"><b>4.6.4</b></a>, <a href="#rfc.xref.status.404.2">1 2.2</a></li>4809 <li>405 Method Not Allowed (status code) <a href="#rfc.xref.status.405.1">4.1</a>, <a href="#rfc.iref.43"><b>4.6.5</b></a>, <a href="#rfc.xref.status.405.2">1 2.2</a></li>4810 <li>406 Not Acceptable (status code) <a href="#rfc.xref.status.406.1">4.1</a>, <a href="#rfc.iref.44"><b>4.6.6</b></a>, <a href="#rfc.xref.status.406.2">1 2.2</a></li>4811 <li>408 Request Timeout (status code) <a href="#rfc.xref.status.408.1">4.1</a>, <a href="#rfc.iref.45"><b>4.6.7</b></a>, <a href="#rfc.xref.status.408.2">1 2.2</a></li>4812 <li>409 Conflict (status code) <a href="#rfc.xref.status.409.1">4.1</a>, <a href="#rfc.iref.46"><b>4.6.8</b></a>, <a href="#rfc.xref.status.409.2">1 2.2</a></li>4813 <li>410 Gone (status code) <a href="#rfc.xref.status.410.1">4.1</a>, <a href="#rfc.iref.47"><b>4.6.9</b></a>, <a href="#rfc.xref.status.410.2">1 2.2</a></li>4814 <li>411 Length Required (status code) <a href="#rfc.xref.status.411.1">4.1</a>, <a href="#rfc.iref.48"><b>4.6.10</b></a>, <a href="#rfc.xref.status.411.2">1 2.2</a></li>4815 <li>413 Request Representation Too Large (status code) <a href="#rfc.xref.status.413.1">4.1</a>, <a href="#rfc.iref.49"><b>4.6.11</b></a>, <a href="#rfc.xref.status.413.2">1 2.2</a></li>4816 <li>414 URI Too Long (status code) <a href="#rfc.xref.status.414.1">4.1</a>, <a href="#rfc.iref.50"><b>4.6.12</b></a>, <a href="#rfc.xref.status.414.2">1 2.2</a></li>4817 <li>415 Unsupported Media Type (status code) <a href="#rfc.xref.status.415.1">4.1</a>, <a href="#rfc.iref.51"><b>4.6.13</b></a>, <a href="#rfc.xref.status.415.2">1 2.2</a></li>4818 <li>417 Expectation Failed (status code) <a href="#rfc.xref.status.417.1">4.1</a>, <a href="#rfc.iref.52"><b>4.6.14</b></a>, <a href="#rfc.xref.status.417.2">1 2.2</a></li>4819 <li>426 Upgrade Required (status code) <a href="#rfc.xref.status.426.1">4.1</a>, <a href="#rfc.iref.53"><b>4.6.15</b></a>, <a href="#rfc.xref.status.426.2">1 2.2</a>, <a href="#rfc.xref.status.426.3">C</a></li>4800 <li>400 Bad Request (status code) <a href="#rfc.xref.status.400.1">4.1</a>, <a href="#rfc.iref.39"><b>4.6.1</b></a>, <a href="#rfc.xref.status.400.2">11.2</a></li> 4801 <li>402 Payment Required (status code) <a href="#rfc.xref.status.402.1">4.1</a>, <a href="#rfc.iref.40"><b>4.6.2</b></a>, <a href="#rfc.xref.status.402.2">11.2</a></li> 4802 <li>403 Forbidden (status code) <a href="#rfc.xref.status.403.1">4.1</a>, <a href="#rfc.iref.41"><b>4.6.3</b></a>, <a href="#rfc.xref.status.403.2">11.2</a></li> 4803 <li>404 Not Found (status code) <a href="#rfc.xref.status.404.1">4.1</a>, <a href="#rfc.iref.42"><b>4.6.4</b></a>, <a href="#rfc.xref.status.404.2">11.2</a></li> 4804 <li>405 Method Not Allowed (status code) <a href="#rfc.xref.status.405.1">4.1</a>, <a href="#rfc.iref.43"><b>4.6.5</b></a>, <a href="#rfc.xref.status.405.2">11.2</a></li> 4805 <li>406 Not Acceptable (status code) <a href="#rfc.xref.status.406.1">4.1</a>, <a href="#rfc.iref.44"><b>4.6.6</b></a>, <a href="#rfc.xref.status.406.2">11.2</a></li> 4806 <li>408 Request Timeout (status code) <a href="#rfc.xref.status.408.1">4.1</a>, <a href="#rfc.iref.45"><b>4.6.7</b></a>, <a href="#rfc.xref.status.408.2">11.2</a></li> 4807 <li>409 Conflict (status code) <a href="#rfc.xref.status.409.1">4.1</a>, <a href="#rfc.iref.46"><b>4.6.8</b></a>, <a href="#rfc.xref.status.409.2">11.2</a></li> 4808 <li>410 Gone (status code) <a href="#rfc.xref.status.410.1">4.1</a>, <a href="#rfc.iref.47"><b>4.6.9</b></a>, <a href="#rfc.xref.status.410.2">11.2</a></li> 4809 <li>411 Length Required (status code) <a href="#rfc.xref.status.411.1">4.1</a>, <a href="#rfc.iref.48"><b>4.6.10</b></a>, <a href="#rfc.xref.status.411.2">11.2</a></li> 4810 <li>413 Request Representation Too Large (status code) <a href="#rfc.xref.status.413.1">4.1</a>, <a href="#rfc.iref.49"><b>4.6.11</b></a>, <a href="#rfc.xref.status.413.2">11.2</a></li> 4811 <li>414 URI Too Long (status code) <a href="#rfc.xref.status.414.1">4.1</a>, <a href="#rfc.iref.50"><b>4.6.12</b></a>, <a href="#rfc.xref.status.414.2">11.2</a></li> 4812 <li>415 Unsupported Media Type (status code) <a href="#rfc.xref.status.415.1">4.1</a>, <a href="#rfc.iref.51"><b>4.6.13</b></a>, <a href="#rfc.xref.status.415.2">11.2</a></li> 4813 <li>417 Expectation Failed (status code) <a href="#rfc.xref.status.417.1">4.1</a>, <a href="#rfc.iref.52"><b>4.6.14</b></a>, <a href="#rfc.xref.status.417.2">11.2</a></li> 4814 <li>426 Upgrade Required (status code) <a href="#rfc.xref.status.426.1">4.1</a>, <a href="#rfc.iref.53"><b>4.6.15</b></a>, <a href="#rfc.xref.status.426.2">11.2</a>, <a href="#rfc.xref.status.426.3">C</a></li> 4820 4815 </ul> 4821 4816 </li> 4822 4817 <li><a id="rfc.index.5" href="#rfc.index.5"><b>5</b></a><ul> 4823 <li>500 Internal Server Error (status code) <a href="#rfc.xref.status.500.1">4.1</a>, <a href="#rfc.iref.54"><b>4.7.1</b></a>, <a href="#rfc.xref.status.500.2">1 2.2</a></li>4824 <li>501 Not Implemented (status code) <a href="#rfc.xref.status.501.1">4.1</a>, <a href="#rfc.iref.55"><b>4.7.2</b></a>, <a href="#rfc.xref.status.501.2">1 2.2</a></li>4825 <li>502 Bad Gateway (status code) <a href="#rfc.xref.status.502.1">4.1</a>, <a href="#rfc.iref.56"><b>4.7.3</b></a>, <a href="#rfc.xref.status.502.2">1 2.2</a></li>4826 <li>503 Service Unavailable (status code) <a href="#rfc.xref.status.503.1">4.1</a>, <a href="#rfc.iref.57"><b>4.7.4</b></a>, <a href="#rfc.xref.status.503.2">1 2.2</a></li>4827 <li>504 Gateway Timeout (status code) <a href="#rfc.xref.status.504.1">4.1</a>, <a href="#rfc.iref.58"><b>4.7.5</b></a>, <a href="#rfc.xref.status.504.2">1 2.2</a></li>4828 <li>505 HTTP Version Not Supported (status code) <a href="#rfc.xref.status.505.1">4.1</a>, <a href="#rfc.iref.59"><b>4.7.6</b></a>, <a href="#rfc.xref.status.505.2">1 2.2</a></li>4818 <li>500 Internal Server Error (status code) <a href="#rfc.xref.status.500.1">4.1</a>, <a href="#rfc.iref.54"><b>4.7.1</b></a>, <a href="#rfc.xref.status.500.2">11.2</a></li> 4819 <li>501 Not Implemented (status code) <a href="#rfc.xref.status.501.1">4.1</a>, <a href="#rfc.iref.55"><b>4.7.2</b></a>, <a href="#rfc.xref.status.501.2">11.2</a></li> 4820 <li>502 Bad Gateway (status code) <a href="#rfc.xref.status.502.1">4.1</a>, <a href="#rfc.iref.56"><b>4.7.3</b></a>, <a href="#rfc.xref.status.502.2">11.2</a></li> 4821 <li>503 Service Unavailable (status code) <a href="#rfc.xref.status.503.1">4.1</a>, <a href="#rfc.iref.57"><b>4.7.4</b></a>, <a href="#rfc.xref.status.503.2">11.2</a></li> 4822 <li>504 Gateway Timeout (status code) <a href="#rfc.xref.status.504.1">4.1</a>, <a href="#rfc.iref.58"><b>4.7.5</b></a>, <a href="#rfc.xref.status.504.2">11.2</a></li> 4823 <li>505 HTTP Version Not Supported (status code) <a href="#rfc.xref.status.505.1">4.1</a>, <a href="#rfc.iref.59"><b>4.7.6</b></a>, <a href="#rfc.xref.status.505.2">11.2</a></li> 4829 4824 </ul> 4830 4825 </li> 4831 4826 <li><a id="rfc.index.A" href="#rfc.index.A"><b>A</b></a><ul> 4832 <li>Accept header field <a href="#rfc.xref.header.accept.1">3.2</a>, <a href="#rfc.xref.header.accept.2"> 7.3</a>, <a href="#rfc.xref.header.accept.3">10.1</a>, <a href="#rfc.iref.a.2"><b>11.11</b></a>, <a href="#rfc.xref.header.accept.4">12.3</a></li>4833 <li>Accept-Charset header field <a href="#rfc.xref.header.accept-charset.1">3.2</a>, <a href="#rfc.xref.header.accept-charset.2"> 10.1</a>, <a href="#rfc.iref.a.3"><b>11.12</b></a>, <a href="#rfc.xref.header.accept-charset.3">12.3</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li>4834 <li>Accept-Encoding header field <a href="#rfc.xref.header.accept-encoding.1">3.2</a>, <a href="#rfc.xref.header.accept-encoding.2"> 7.2</a>, <a href="#rfc.xref.header.accept-encoding.3">10.1</a>, <a href="#rfc.iref.a.4"><b>11.13</b></a>, <a href="#rfc.xref.header.accept-encoding.4">12.3</a>, <a href="#rfc.xref.header.accept-encoding.5">12.4</a></li>4835 <li>Accept-Language header field <a href="#rfc.xref.header.accept-language.1">3.2</a>, <a href="#rfc.xref.header.accept-language.2"> 10.1</a>, <a href="#rfc.iref.a.5"><b>11.14</b></a>, <a href="#rfc.xref.header.accept-language.3">12.3</a></li>4836 <li>Allow header field <a href="#rfc.xref.header.allow.1">2</a>, <a href="#rfc.xref.header.allow.2">3.3</a>, <a href="#rfc.iref.a.1"><b>1 1.1</b></a>, <a href="#rfc.xref.header.allow.3">12.3</a>, <a href="#rfc.xref.header.allow.4">C</a></li>4827 <li>Accept header field <a href="#rfc.xref.header.accept.1">3.2</a>, <a href="#rfc.xref.header.accept.2">6.5</a>, <a href="#rfc.xref.header.accept.3">9.1</a>, <a href="#rfc.iref.a.2"><b>10.11</b></a>, <a href="#rfc.xref.header.accept.4">11.3</a></li> 4828 <li>Accept-Charset header field <a href="#rfc.xref.header.accept-charset.1">3.2</a>, <a href="#rfc.xref.header.accept-charset.2">9.1</a>, <a href="#rfc.iref.a.3"><b>10.12</b></a>, <a href="#rfc.xref.header.accept-charset.3">11.3</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li> 4829 <li>Accept-Encoding header field <a href="#rfc.xref.header.accept-encoding.1">3.2</a>, <a href="#rfc.xref.header.accept-encoding.2">6.4</a>, <a href="#rfc.xref.header.accept-encoding.3">9.1</a>, <a href="#rfc.iref.a.4"><b>10.13</b></a>, <a href="#rfc.xref.header.accept-encoding.4">11.3</a>, <a href="#rfc.xref.header.accept-encoding.5">11.4</a></li> 4830 <li>Accept-Language header field <a href="#rfc.xref.header.accept-language.1">3.2</a>, <a href="#rfc.xref.header.accept-language.2">9.1</a>, <a href="#rfc.iref.a.5"><b>10.14</b></a>, <a href="#rfc.xref.header.accept-language.3">11.3</a></li> 4831 <li>Allow header field <a href="#rfc.xref.header.allow.1">2</a>, <a href="#rfc.xref.header.allow.2">3.3</a>, <a href="#rfc.iref.a.1"><b>10.1</b></a>, <a href="#rfc.xref.header.allow.3">11.3</a>, <a href="#rfc.xref.header.allow.4">C</a></li> 4837 4832 </ul> 4838 4833 </li> … … 4840 4835 <li>Coding Format 4841 4836 <ul> 4842 <li>compress <a href="#rfc.iref.c.4"> 7.2</a></li>4843 <li>deflate <a href="#rfc.iref.c.5"> 7.2</a></li>4844 <li>gzip <a href="#rfc.iref.c.6"> 7.2</a></li>4837 <li>compress <a href="#rfc.iref.c.4">6.4</a></li> 4838 <li>deflate <a href="#rfc.iref.c.5">6.4</a></li> 4839 <li>gzip <a href="#rfc.iref.c.6">6.4</a></li> 4845 4840 </ul> 4846 4841 </li> 4847 <li>compress (Coding Format) <a href="#rfc.iref.c.3"> 7.2</a></li>4848 <li>CONNECT method <a href="#rfc.iref.c.2"><b>2.3.8</b></a>, <a href="#rfc.xref.CONNECT.1">1 2.1</a>, <a href="#rfc.xref.CONNECT.2">C</a></li>4842 <li>compress (Coding Format) <a href="#rfc.iref.c.3">6.4</a></li> 4843 <li>CONNECT method <a href="#rfc.iref.c.2"><b>2.3.8</b></a>, <a href="#rfc.xref.CONNECT.1">11.1</a>, <a href="#rfc.xref.CONNECT.2">C</a></li> 4849 4844 <li>content negotiation <a href="#rfc.iref.c.1">1.1</a></li> 4850 <li>Content-Encoding header field <a href="#rfc.xref.header.content-encoding.1"> 7.2</a>, <a href="#rfc.xref.header.content-encoding.2">9.1</a>, <a href="#rfc.iref.c.7"><b>11.15</b></a>, <a href="#rfc.xref.header.content-encoding.3">11.15</a>, <a href="#rfc.xref.header.content-encoding.4">12.3</a></li>4851 <li>Content-Language header field <a href="#rfc.xref.header.content-language.1"> 9.1</a>, <a href="#rfc.iref.c.8"><b>11.16</b></a>, <a href="#rfc.xref.header.content-language.2">12.3</a></li>4852 <li>Content-Location header field <a href="#rfc.xref.header.content-location.1">2.3.4</a>, <a href="#rfc.xref.header.content-location.2"> 9.1</a>, <a href="#rfc.xref.header.content-location.3">11.5</a>, <a href="#rfc.iref.c.9"><b>11.17</b></a>, <a href="#rfc.xref.header.content-location.4">12.3</a>, <a href="#rfc.xref.header.content-location.5">C</a></li>4845 <li>Content-Encoding header field <a href="#rfc.xref.header.content-encoding.1">6.4</a>, <a href="#rfc.xref.header.content-encoding.2">8.1</a>, <a href="#rfc.iref.c.7"><b>10.15</b></a>, <a href="#rfc.xref.header.content-encoding.3">10.15</a>, <a href="#rfc.xref.header.content-encoding.4">11.3</a></li> 4846 <li>Content-Language header field <a href="#rfc.xref.header.content-language.1">8.1</a>, <a href="#rfc.iref.c.8"><b>10.16</b></a>, <a href="#rfc.xref.header.content-language.2">11.3</a></li> 4847 <li>Content-Location header field <a href="#rfc.xref.header.content-location.1">2.3.4</a>, <a href="#rfc.xref.header.content-location.2">8.1</a>, <a href="#rfc.xref.header.content-location.3">10.5</a>, <a href="#rfc.iref.c.9"><b>10.17</b></a>, <a href="#rfc.xref.header.content-location.4">11.3</a>, <a href="#rfc.xref.header.content-location.5">C</a></li> 4853 4848 <li>Content-Transfer-Encoding header field <a href="#rfc.iref.c.11">A.5</a>, <a href="#rfc.xref.no.content-transfer-encoding.1">C</a></li> 4854 <li>Content-Type header field <a href="#rfc.xref.header.content-type.1">3.1</a>, <a href="#rfc.xref.header.content-type.2">4</a>, <a href="#rfc.xref.header.content-type.3"> 7.3</a>, <a href="#rfc.xref.header.content-type.4">9.1</a>, <a href="#rfc.iref.c.10"><b>11.18</b></a>, <a href="#rfc.xref.header.content-type.5">12.3</a></li>4849 <li>Content-Type header field <a href="#rfc.xref.header.content-type.1">3.1</a>, <a href="#rfc.xref.header.content-type.2">4</a>, <a href="#rfc.xref.header.content-type.3">6.5</a>, <a href="#rfc.xref.header.content-type.4">8.1</a>, <a href="#rfc.iref.c.10"><b>10.18</b></a>, <a href="#rfc.xref.header.content-type.5">11.3</a></li> 4855 4850 </ul> 4856 4851 </li> 4857 4852 <li><a id="rfc.index.D" href="#rfc.index.D"><b>D</b></a><ul> 4858 <li>Date header field <a href="#rfc.xref.header.date.1">3.3</a>, <a href="#rfc.iref.d.3"><b>1 1.2</b></a>, <a href="#rfc.xref.header.date.2">12.3</a></li>4859 <li>deflate (Coding Format) <a href="#rfc.iref.d.2"> 7.2</a></li>4860 <li>DELETE method <a href="#rfc.iref.d.1"><b>2.3.6</b></a>, <a href="#rfc.xref.DELETE.1">1 2.1</a></li>4861 <li><em>draft-reschke-http-status-308</em> <a href="#rfc.xref.draft-reschke-http-status-308.1">4.5.7</a>, <a href="#draft-reschke-http-status-308"><b>1 5.2</b></a></li>4853 <li>Date header field <a href="#rfc.xref.header.date.1">3.3</a>, <a href="#rfc.iref.d.3"><b>10.2</b></a>, <a href="#rfc.xref.header.date.2">11.3</a></li> 4854 <li>deflate (Coding Format) <a href="#rfc.iref.d.2">6.4</a></li> 4855 <li>DELETE method <a href="#rfc.iref.d.1"><b>2.3.6</b></a>, <a href="#rfc.xref.DELETE.1">11.1</a></li> 4856 <li><em>draft-reschke-http-status-308</em> <a href="#rfc.xref.draft-reschke-http-status-308.1">4.5.7</a>, <a href="#draft-reschke-http-status-308"><b>14.2</b></a></li> 4862 4857 </ul> 4863 4858 </li> 4864 4859 <li><a id="rfc.index.E" href="#rfc.index.E"><b>E</b></a><ul> 4865 <li>Expect header field <a href="#rfc.xref.header.expect.1">3.2</a>, <a href="#rfc.xref.header.expect.2">4.6.14</a>, <a href="#rfc.iref.e.1"><b>1 1.3</b></a>, <a href="#rfc.xref.header.expect.3">12.3</a>, <a href="#rfc.xref.header.expect.4">C</a></li>4860 <li>Expect header field <a href="#rfc.xref.header.expect.1">3.2</a>, <a href="#rfc.xref.header.expect.2">4.6.14</a>, <a href="#rfc.iref.e.1"><b>10.3</b></a>, <a href="#rfc.xref.header.expect.3">11.3</a>, <a href="#rfc.xref.header.expect.4">C</a></li> 4866 4861 <li>Expect Values 4867 4862 <ul> 4868 <li>100-continue <a href="#rfc.iref.e.2"><b>1 1.3</b></a></li>4863 <li>100-continue <a href="#rfc.iref.e.2"><b>10.3</b></a></li> 4869 4864 </ul> 4870 4865 </li> … … 4872 4867 </li> 4873 4868 <li><a id="rfc.index.F" href="#rfc.index.F"><b>F</b></a><ul> 4874 <li>From header field <a href="#rfc.xref.header.from.1">3.2</a>, <a href="#rfc.iref.f.1"><b>1 1.4</b></a>, <a href="#rfc.xref.header.from.2">12.3</a></li>4869 <li>From header field <a href="#rfc.xref.header.from.1">3.2</a>, <a href="#rfc.iref.f.1"><b>10.4</b></a>, <a href="#rfc.xref.header.from.2">11.3</a></li> 4875 4870 </ul> 4876 4871 </li> 4877 4872 <li><a id="rfc.index.G" href="#rfc.index.G"><b>G</b></a><ul> 4878 <li>GET method <a href="#rfc.iref.g.2"><b>2.3.2</b></a>, <a href="#rfc.xref.GET.1">1 2.1</a></li>4873 <li>GET method <a href="#rfc.iref.g.2"><b>2.3.2</b></a>, <a href="#rfc.xref.GET.1">11.1</a></li> 4879 4874 <li><tt>Grammar</tt> 4880 4875 <ul> 4881 <li><tt>Accept</tt> <a href="#rfc.iref.g.49"><b>1 1.11</b></a></li>4882 <li><tt>Accept-Charset</tt> <a href="#rfc.iref.g.53"><b>1 1.12</b></a></li>4883 <li><tt>Accept-Encoding</tt> <a href="#rfc.iref.g.54"><b>1 1.13</b></a></li>4884 <li><tt>accept-ext</tt> <a href="#rfc.iref.g.52"><b>1 1.11</b></a></li>4885 <li><tt>Accept-Language</tt> <a href="#rfc.iref.g.56"><b>1 1.14</b></a></li>4886 <li><tt>accept-params</tt> <a href="#rfc.iref.g.51"><b>1 1.11</b></a></li>4887 <li><tt>Allow</tt> <a href="#rfc.iref.g.34"><b>1 1.1</b></a></li>4876 <li><tt>Accept</tt> <a href="#rfc.iref.g.49"><b>10.11</b></a></li> 4877 <li><tt>Accept-Charset</tt> <a href="#rfc.iref.g.53"><b>10.12</b></a></li> 4878 <li><tt>Accept-Encoding</tt> <a href="#rfc.iref.g.54"><b>10.13</b></a></li> 4879 <li><tt>accept-ext</tt> <a href="#rfc.iref.g.52"><b>10.11</b></a></li> 4880 <li><tt>Accept-Language</tt> <a href="#rfc.iref.g.56"><b>10.14</b></a></li> 4881 <li><tt>accept-params</tt> <a href="#rfc.iref.g.51"><b>10.11</b></a></li> 4882 <li><tt>Allow</tt> <a href="#rfc.iref.g.34"><b>10.1</b></a></li> 4888 4883 <li><tt>asctime-date</tt> <a href="#rfc.iref.g.21"><b>6.1</b></a></li> 4889 <li><tt>attribute</tt> <a href="#rfc.iref.g.31"><b> 7.3</b></a></li>4890 <li><tt>charset</tt> <a href="#rfc.iref.g.24"><b> 7.1</b></a></li>4891 <li><tt>codings</tt> <a href="#rfc.iref.g.55"><b>1 1.13</b></a></li>4892 <li><tt>content-coding</tt> <a href="#rfc.iref.g.25"><b> 7.2</b></a></li>4893 <li><tt>Content-Encoding</tt> <a href="#rfc.iref.g.58"><b>1 1.15</b></a></li>4894 <li><tt>Content-Language</tt> <a href="#rfc.iref.g.59"><b>1 1.16</b></a></li>4895 <li><tt>Content-Location</tt> <a href="#rfc.iref.g.60"><b>1 1.17</b></a></li>4896 <li><tt>Content-Type</tt> <a href="#rfc.iref.g.61"><b>1 1.18</b></a></li>4897 <li><tt>Date</tt> <a href="#rfc.iref.g.35"><b>1 1.2</b></a></li>4884 <li><tt>attribute</tt> <a href="#rfc.iref.g.31"><b>6.5</b></a></li> 4885 <li><tt>charset</tt> <a href="#rfc.iref.g.24"><b>6.3</b></a></li> 4886 <li><tt>codings</tt> <a href="#rfc.iref.g.55"><b>10.13</b></a></li> 4887 <li><tt>content-coding</tt> <a href="#rfc.iref.g.25"><b>6.4</b></a></li> 4888 <li><tt>Content-Encoding</tt> <a href="#rfc.iref.g.58"><b>10.15</b></a></li> 4889 <li><tt>Content-Language</tt> <a href="#rfc.iref.g.59"><b>10.16</b></a></li> 4890 <li><tt>Content-Location</tt> <a href="#rfc.iref.g.60"><b>10.17</b></a></li> 4891 <li><tt>Content-Type</tt> <a href="#rfc.iref.g.61"><b>10.18</b></a></li> 4892 <li><tt>Date</tt> <a href="#rfc.iref.g.35"><b>10.2</b></a></li> 4898 4893 <li><tt>date1</tt> <a href="#rfc.iref.g.8"><b>6.1</b></a></li> 4899 4894 <li><tt>day</tt> <a href="#rfc.iref.g.15"><b>6.1</b></a></li> 4900 4895 <li><tt>day-name</tt> <a href="#rfc.iref.g.13"><b>6.1</b></a></li> 4901 4896 <li><tt>day-name-l</tt> <a href="#rfc.iref.g.14"><b>6.1</b></a></li> 4902 <li><tt>delta-seconds</tt> <a href="#rfc.iref.g.46"><b>1 1.8</b></a></li>4903 <li><tt>Expect</tt> <a href="#rfc.iref.g.36"><b>1 1.3</b></a></li>4904 <li><tt>expect-name</tt> <a href="#rfc.iref.g.40"><b>1 1.3</b></a></li>4905 <li><tt>expect-param</tt> <a href="#rfc.iref.g.38"><b>1 1.3</b></a></li>4906 <li><tt>expect-value</tt> <a href="#rfc.iref.g.39"><b>1 1.3</b></a></li>4907 <li><tt>expectation</tt> <a href="#rfc.iref.g.37"><b>1 1.3</b></a></li>4897 <li><tt>delta-seconds</tt> <a href="#rfc.iref.g.46"><b>10.8</b></a></li> 4898 <li><tt>Expect</tt> <a href="#rfc.iref.g.36"><b>10.3</b></a></li> 4899 <li><tt>expect-name</tt> <a href="#rfc.iref.g.40"><b>10.3</b></a></li> 4900 <li><tt>expect-param</tt> <a href="#rfc.iref.g.38"><b>10.3</b></a></li> 4901 <li><tt>expect-value</tt> <a href="#rfc.iref.g.39"><b>10.3</b></a></li> 4902 <li><tt>expectation</tt> <a href="#rfc.iref.g.37"><b>10.3</b></a></li> 4908 4903 <li><tt>extension-code</tt> <a href="#rfc.iref.g.4"><b>4</b></a></li> 4909 <li><tt>From</tt> <a href="#rfc.iref.g.41"><b>1 1.4</b></a></li>4904 <li><tt>From</tt> <a href="#rfc.iref.g.41"><b>10.4</b></a></li> 4910 4905 <li><tt>GMT</tt> <a href="#rfc.iref.g.18"><b>6.1</b></a></li> 4911 4906 <li><tt>hour</tt> <a href="#rfc.iref.g.10"><b>6.1</b></a></li> 4912 4907 <li><tt>HTTP-date</tt> <a href="#rfc.iref.g.6"><b>6.1</b></a></li> 4913 <li><tt>language-range</tt> <a href="#rfc.iref.g.57"><b>1 1.14</b></a></li>4914 <li><tt>language-tag</tt> <a href="#rfc.iref.g.33"><b> 7.4</b></a></li>4915 <li><tt>Location</tt> <a href="#rfc.iref.g.42"><b>1 1.5</b></a></li>4916 <li><tt>Max-Forwards</tt> <a href="#rfc.iref.g.43"><b>1 1.6</b></a></li>4917 <li><tt>media-range</tt> <a href="#rfc.iref.g.50"><b>1 1.11</b></a></li>4918 <li><tt>media-type</tt> <a href="#rfc.iref.g.27"><b> 7.3</b></a></li>4908 <li><tt>language-range</tt> <a href="#rfc.iref.g.57"><b>10.14</b></a></li> 4909 <li><tt>language-tag</tt> <a href="#rfc.iref.g.33"><b>6.6</b></a></li> 4910 <li><tt>Location</tt> <a href="#rfc.iref.g.42"><b>10.5</b></a></li> 4911 <li><tt>Max-Forwards</tt> <a href="#rfc.iref.g.43"><b>10.6</b></a></li> 4912 <li><tt>media-range</tt> <a href="#rfc.iref.g.50"><b>10.11</b></a></li> 4913 <li><tt>media-type</tt> <a href="#rfc.iref.g.27"><b>6.5</b></a></li> 4919 4914 <li><tt>method</tt> <a href="#rfc.iref.g.1"><b>2</b></a></li> 4920 4915 <li><tt>MIME-Version</tt> <a href="#rfc.iref.g.62"><b>A.1</b></a></li> … … 4922 4917 <li><tt>month</tt> <a href="#rfc.iref.g.16"><b>6.1</b></a></li> 4923 4918 <li><tt>obs-date</tt> <a href="#rfc.iref.g.19"><b>6.1</b></a></li> 4924 <li><tt>parameter</tt> <a href="#rfc.iref.g.30"><b> 7.3</b></a></li>4919 <li><tt>parameter</tt> <a href="#rfc.iref.g.30"><b>6.5</b></a></li> 4925 4920 <li><tt>product</tt> <a href="#rfc.iref.g.22"><b>6.2</b></a></li> 4926 4921 <li><tt>product-version</tt> <a href="#rfc.iref.g.23"><b>6.2</b></a></li> 4927 4922 <li><tt>reason-phrase</tt> <a href="#rfc.iref.g.5"><b>4</b></a></li> 4928 <li><tt>Referer</tt> <a href="#rfc.iref.g.44"><b>1 1.7</b></a></li>4929 <li><tt>Retry-After</tt> <a href="#rfc.iref.g.45"><b>1 1.8</b></a></li>4923 <li><tt>Referer</tt> <a href="#rfc.iref.g.44"><b>10.7</b></a></li> 4924 <li><tt>Retry-After</tt> <a href="#rfc.iref.g.45"><b>10.8</b></a></li> 4930 4925 <li><tt>rfc1123-date</tt> <a href="#rfc.iref.g.7"><b>6.1</b></a></li> 4931 4926 <li><tt>rfc850-date</tt> <a href="#rfc.iref.g.20"><b>6.1</b></a></li> 4932 4927 <li><tt>second</tt> <a href="#rfc.iref.g.12"><b>6.1</b></a></li> 4933 <li><tt>Server</tt> <a href="#rfc.iref.g.47"><b>1 1.9</b></a></li>4928 <li><tt>Server</tt> <a href="#rfc.iref.g.47"><b>10.9</b></a></li> 4934 4929 <li><tt>status-code</tt> <a href="#rfc.iref.g.3"><b>4</b></a></li> 4935 <li><tt>subtype</tt> <a href="#rfc.iref.g.29"><b> 7.3</b></a></li>4930 <li><tt>subtype</tt> <a href="#rfc.iref.g.29"><b>6.5</b></a></li> 4936 4931 <li><tt>time-of-day</tt> <a href="#rfc.iref.g.9"><b>6.1</b></a></li> 4937 <li><tt>type</tt> <a href="#rfc.iref.g.28"><b> 7.3</b></a></li>4938 <li><tt>User-Agent</tt> <a href="#rfc.iref.g.48"><b>1 1.10</b></a></li>4939 <li><tt>value</tt> <a href="#rfc.iref.g.32"><b> 7.3</b></a></li>4932 <li><tt>type</tt> <a href="#rfc.iref.g.28"><b>6.5</b></a></li> 4933 <li><tt>User-Agent</tt> <a href="#rfc.iref.g.48"><b>10.10</b></a></li> 4934 <li><tt>value</tt> <a href="#rfc.iref.g.32"><b>6.5</b></a></li> 4940 4935 <li><tt>year</tt> <a href="#rfc.iref.g.17"><b>6.1</b></a></li> 4941 4936 </ul> 4942 4937 </li> 4943 <li>gzip (Coding Format) <a href="#rfc.iref.g.26"> 7.2</a></li>4938 <li>gzip (Coding Format) <a href="#rfc.iref.g.26">6.4</a></li> 4944 4939 </ul> 4945 4940 </li> 4946 4941 <li><a id="rfc.index.H" href="#rfc.index.H"><b>H</b></a><ul> 4947 <li>HEAD method <a href="#rfc.iref.h.1"><b>2.3.3</b></a>, <a href="#rfc.xref.HEAD.1">1 2.1</a></li>4942 <li>HEAD method <a href="#rfc.iref.h.1"><b>2.3.3</b></a>, <a href="#rfc.xref.HEAD.1">11.1</a></li> 4948 4943 <li>Header Fields 4949 4944 <ul> 4950 <li>Accept <a href="#rfc.xref.header.accept.1">3.2</a>, <a href="#rfc.xref.header.accept.2"> 7.3</a>, <a href="#rfc.xref.header.accept.3">10.1</a>, <a href="#rfc.iref.h.12"><b>11.11</b></a>, <a href="#rfc.xref.header.accept.4">12.3</a></li>4951 <li>Accept-Charset <a href="#rfc.xref.header.accept-charset.1">3.2</a>, <a href="#rfc.xref.header.accept-charset.2"> 10.1</a>, <a href="#rfc.iref.h.13"><b>11.12</b></a>, <a href="#rfc.xref.header.accept-charset.3">12.3</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li>4952 <li>Accept-Encoding <a href="#rfc.xref.header.accept-encoding.1">3.2</a>, <a href="#rfc.xref.header.accept-encoding.2"> 7.2</a>, <a href="#rfc.xref.header.accept-encoding.3">10.1</a>, <a href="#rfc.iref.h.14"><b>11.13</b></a>, <a href="#rfc.xref.header.accept-encoding.4">12.3</a>, <a href="#rfc.xref.header.accept-encoding.5">12.4</a></li>4953 <li>Accept-Language <a href="#rfc.xref.header.accept-language.1">3.2</a>, <a href="#rfc.xref.header.accept-language.2"> 10.1</a>, <a href="#rfc.iref.h.15"><b>11.14</b></a>, <a href="#rfc.xref.header.accept-language.3">12.3</a></li>4954 <li>Allow <a href="#rfc.xref.header.allow.1">2</a>, <a href="#rfc.xref.header.allow.2">3.3</a>, <a href="#rfc.iref.h.2"><b>1 1.1</b></a>, <a href="#rfc.xref.header.allow.3">12.3</a>, <a href="#rfc.xref.header.allow.4">C</a></li>4955 <li>Content-Encoding <a href="#rfc.xref.header.content-encoding.1"> 7.2</a>, <a href="#rfc.xref.header.content-encoding.2">9.1</a>, <a href="#rfc.iref.h.16"><b>11.15</b></a>, <a href="#rfc.xref.header.content-encoding.3">11.15</a>, <a href="#rfc.xref.header.content-encoding.4">12.3</a></li>4956 <li>Content-Language <a href="#rfc.xref.header.content-language.1"> 9.1</a>, <a href="#rfc.iref.h.17"><b>11.16</b></a>, <a href="#rfc.xref.header.content-language.2">12.3</a></li>4957 <li>Content-Location <a href="#rfc.xref.header.content-location.1">2.3.4</a>, <a href="#rfc.xref.header.content-location.2"> 9.1</a>, <a href="#rfc.xref.header.content-location.3">11.5</a>, <a href="#rfc.iref.h.18"><b>11.17</b></a>, <a href="#rfc.xref.header.content-location.4">12.3</a>, <a href="#rfc.xref.header.content-location.5">C</a></li>4945 <li>Accept <a href="#rfc.xref.header.accept.1">3.2</a>, <a href="#rfc.xref.header.accept.2">6.5</a>, <a href="#rfc.xref.header.accept.3">9.1</a>, <a href="#rfc.iref.h.12"><b>10.11</b></a>, <a href="#rfc.xref.header.accept.4">11.3</a></li> 4946 <li>Accept-Charset <a href="#rfc.xref.header.accept-charset.1">3.2</a>, <a href="#rfc.xref.header.accept-charset.2">9.1</a>, <a href="#rfc.iref.h.13"><b>10.12</b></a>, <a href="#rfc.xref.header.accept-charset.3">11.3</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li> 4947 <li>Accept-Encoding <a href="#rfc.xref.header.accept-encoding.1">3.2</a>, <a href="#rfc.xref.header.accept-encoding.2">6.4</a>, <a href="#rfc.xref.header.accept-encoding.3">9.1</a>, <a href="#rfc.iref.h.14"><b>10.13</b></a>, <a href="#rfc.xref.header.accept-encoding.4">11.3</a>, <a href="#rfc.xref.header.accept-encoding.5">11.4</a></li> 4948 <li>Accept-Language <a href="#rfc.xref.header.accept-language.1">3.2</a>, <a href="#rfc.xref.header.accept-language.2">9.1</a>, <a href="#rfc.iref.h.15"><b>10.14</b></a>, <a href="#rfc.xref.header.accept-language.3">11.3</a></li> 4949 <li>Allow <a href="#rfc.xref.header.allow.1">2</a>, <a href="#rfc.xref.header.allow.2">3.3</a>, <a href="#rfc.iref.h.2"><b>10.1</b></a>, <a href="#rfc.xref.header.allow.3">11.3</a>, <a href="#rfc.xref.header.allow.4">C</a></li> 4950 <li>Content-Encoding <a href="#rfc.xref.header.content-encoding.1">6.4</a>, <a href="#rfc.xref.header.content-encoding.2">8.1</a>, <a href="#rfc.iref.h.16"><b>10.15</b></a>, <a href="#rfc.xref.header.content-encoding.3">10.15</a>, <a href="#rfc.xref.header.content-encoding.4">11.3</a></li> 4951 <li>Content-Language <a href="#rfc.xref.header.content-language.1">8.1</a>, <a href="#rfc.iref.h.17"><b>10.16</b></a>, <a href="#rfc.xref.header.content-language.2">11.3</a></li> 4952 <li>Content-Location <a href="#rfc.xref.header.content-location.1">2.3.4</a>, <a href="#rfc.xref.header.content-location.2">8.1</a>, <a href="#rfc.xref.header.content-location.3">10.5</a>, <a href="#rfc.iref.h.18"><b>10.17</b></a>, <a href="#rfc.xref.header.content-location.4">11.3</a>, <a href="#rfc.xref.header.content-location.5">C</a></li> 4958 4953 <li>Content-Transfer-Encoding <a href="#rfc.iref.h.21">A.5</a>, <a href="#rfc.xref.no.content-transfer-encoding.1">C</a></li> 4959 <li>Content-Type <a href="#rfc.xref.header.content-type.1">3.1</a>, <a href="#rfc.xref.header.content-type.2">4</a>, <a href="#rfc.xref.header.content-type.3"> 7.3</a>, <a href="#rfc.xref.header.content-type.4">9.1</a>, <a href="#rfc.iref.h.19"><b>11.18</b></a>, <a href="#rfc.xref.header.content-type.5">12.3</a></li>4960 <li>Date <a href="#rfc.xref.header.date.1">3.3</a>, <a href="#rfc.iref.h.3"><b>1 1.2</b></a>, <a href="#rfc.xref.header.date.2">12.3</a></li>4961 <li>Expect <a href="#rfc.xref.header.expect.1">3.2</a>, <a href="#rfc.xref.header.expect.2">4.6.14</a>, <a href="#rfc.iref.h.4"><b>1 1.3</b></a>, <a href="#rfc.xref.header.expect.3">12.3</a>, <a href="#rfc.xref.header.expect.4">C</a></li>4962 <li>From <a href="#rfc.xref.header.from.1">3.2</a>, <a href="#rfc.iref.h.5"><b>1 1.4</b></a>, <a href="#rfc.xref.header.from.2">12.3</a></li>4963 <li>Location <a href="#rfc.xref.header.location.1">2.3.4</a>, <a href="#rfc.xref.header.location.2">3.3</a>, <a href="#rfc.xref.header.location.3">4.5</a>, <a href="#rfc.iref.h.6"><b>1 1.5</b></a>, <a href="#rfc.xref.header.location.4">12.3</a>, <a href="#rfc.xref.header.location.5">C</a></li>4964 <li>Max-Forwards <a href="#rfc.xref.header.max-forwards.1">2.3.1</a>, <a href="#rfc.xref.header.max-forwards.2">2.3.7</a>, <a href="#rfc.xref.header.max-forwards.3">3.2</a>, <a href="#rfc.iref.h.7"><b>1 1.6</b></a>, <a href="#rfc.xref.header.max-forwards.4">12.3</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li>4965 <li>MIME-Version <a href="#rfc.xref.mime-version.1">1 2.3</a>, <a href="#rfc.iref.h.20"><b>A.1</b></a></li>4966 <li>Referer <a href="#rfc.xref.header.referer.1">3.2</a>, <a href="#rfc.iref.h.8"><b>1 1.7</b></a>, <a href="#rfc.xref.header.referer.2">12.3</a>, <a href="#rfc.xref.header.referer.3">C</a></li>4967 <li>Retry-After <a href="#rfc.xref.header.retry-after.1">3.3</a>, <a href="#rfc.xref.header.retry-after.2">4.7.4</a>, <a href="#rfc.iref.h.9"><b>1 1.8</b></a>, <a href="#rfc.xref.header.retry-after.3">12.3</a></li>4968 <li>Server <a href="#rfc.xref.header.server.1">3.3</a>, <a href="#rfc.iref.h.10"><b>1 1.9</b></a>, <a href="#rfc.xref.header.server.2">12.3</a>, <a href="#rfc.xref.header.server.3">13.1</a>, <a href="#rfc.xref.header.server.4">C</a></li>4969 <li>User-Agent <a href="#rfc.xref.header.user-agent.1">3.2</a>, <a href="#rfc.xref.header.user-agent.2"> 10.1</a>, <a href="#rfc.iref.h.11"><b>11.10</b></a>, <a href="#rfc.xref.header.user-agent.3">12.3</a>, <a href="#rfc.xref.header.user-agent.4">13.1</a></li>4954 <li>Content-Type <a href="#rfc.xref.header.content-type.1">3.1</a>, <a href="#rfc.xref.header.content-type.2">4</a>, <a href="#rfc.xref.header.content-type.3">6.5</a>, <a href="#rfc.xref.header.content-type.4">8.1</a>, <a href="#rfc.iref.h.19"><b>10.18</b></a>, <a href="#rfc.xref.header.content-type.5">11.3</a></li> 4955 <li>Date <a href="#rfc.xref.header.date.1">3.3</a>, <a href="#rfc.iref.h.3"><b>10.2</b></a>, <a href="#rfc.xref.header.date.2">11.3</a></li> 4956 <li>Expect <a href="#rfc.xref.header.expect.1">3.2</a>, <a href="#rfc.xref.header.expect.2">4.6.14</a>, <a href="#rfc.iref.h.4"><b>10.3</b></a>, <a href="#rfc.xref.header.expect.3">11.3</a>, <a href="#rfc.xref.header.expect.4">C</a></li> 4957 <li>From <a href="#rfc.xref.header.from.1">3.2</a>, <a href="#rfc.iref.h.5"><b>10.4</b></a>, <a href="#rfc.xref.header.from.2">11.3</a></li> 4958 <li>Location <a href="#rfc.xref.header.location.1">2.3.4</a>, <a href="#rfc.xref.header.location.2">3.3</a>, <a href="#rfc.xref.header.location.3">4.5</a>, <a href="#rfc.iref.h.6"><b>10.5</b></a>, <a href="#rfc.xref.header.location.4">11.3</a>, <a href="#rfc.xref.header.location.5">C</a></li> 4959 <li>Max-Forwards <a href="#rfc.xref.header.max-forwards.1">2.3.1</a>, <a href="#rfc.xref.header.max-forwards.2">2.3.7</a>, <a href="#rfc.xref.header.max-forwards.3">3.2</a>, <a href="#rfc.iref.h.7"><b>10.6</b></a>, <a href="#rfc.xref.header.max-forwards.4">11.3</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li> 4960 <li>MIME-Version <a href="#rfc.xref.mime-version.1">11.3</a>, <a href="#rfc.iref.h.20"><b>A.1</b></a></li> 4961 <li>Referer <a href="#rfc.xref.header.referer.1">3.2</a>, <a href="#rfc.iref.h.8"><b>10.7</b></a>, <a href="#rfc.xref.header.referer.2">11.3</a>, <a href="#rfc.xref.header.referer.3">C</a></li> 4962 <li>Retry-After <a href="#rfc.xref.header.retry-after.1">3.3</a>, <a href="#rfc.xref.header.retry-after.2">4.7.4</a>, <a href="#rfc.iref.h.9"><b>10.8</b></a>, <a href="#rfc.xref.header.retry-after.3">11.3</a></li> 4963 <li>Server <a href="#rfc.xref.header.server.1">3.3</a>, <a href="#rfc.iref.h.10"><b>10.9</b></a>, <a href="#rfc.xref.header.server.2">11.3</a>, <a href="#rfc.xref.header.server.3">12.1</a>, <a href="#rfc.xref.header.server.4">C</a></li> 4964 <li>User-Agent <a href="#rfc.xref.header.user-agent.1">3.2</a>, <a href="#rfc.xref.header.user-agent.2">9.1</a>, <a href="#rfc.iref.h.11"><b>10.10</b></a>, <a href="#rfc.xref.header.user-agent.3">11.3</a>, <a href="#rfc.xref.header.user-agent.4">12.1</a></li> 4970 4965 </ul> 4971 4966 </li> … … 4977 4972 </li> 4978 4973 <li><a id="rfc.index.L" href="#rfc.index.L"><b>L</b></a><ul> 4979 <li>Location header field <a href="#rfc.xref.header.location.1">2.3.4</a>, <a href="#rfc.xref.header.location.2">3.3</a>, <a href="#rfc.xref.header.location.3">4.5</a>, <a href="#rfc.iref.l.1"><b>1 1.5</b></a>, <a href="#rfc.xref.header.location.4">12.3</a>, <a href="#rfc.xref.header.location.5">C</a></li>4974 <li>Location header field <a href="#rfc.xref.header.location.1">2.3.4</a>, <a href="#rfc.xref.header.location.2">3.3</a>, <a href="#rfc.xref.header.location.3">4.5</a>, <a href="#rfc.iref.l.1"><b>10.5</b></a>, <a href="#rfc.xref.header.location.4">11.3</a>, <a href="#rfc.xref.header.location.5">C</a></li> 4980 4975 </ul> 4981 4976 </li> 4982 4977 <li><a id="rfc.index.M" href="#rfc.index.M"><b>M</b></a><ul> 4983 <li>Max-Forwards header field <a href="#rfc.xref.header.max-forwards.1">2.3.1</a>, <a href="#rfc.xref.header.max-forwards.2">2.3.7</a>, <a href="#rfc.xref.header.max-forwards.3">3.2</a>, <a href="#rfc.iref.m.9"><b>1 1.6</b></a>, <a href="#rfc.xref.header.max-forwards.4">12.3</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li>4978 <li>Max-Forwards header field <a href="#rfc.xref.header.max-forwards.1">2.3.1</a>, <a href="#rfc.xref.header.max-forwards.2">2.3.7</a>, <a href="#rfc.xref.header.max-forwards.3">3.2</a>, <a href="#rfc.iref.m.9"><b>10.6</b></a>, <a href="#rfc.xref.header.max-forwards.4">11.3</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li> 4984 4979 <li>Methods 4985 4980 <ul> 4986 <li>CONNECT <a href="#rfc.iref.m.8"><b>2.3.8</b></a>, <a href="#rfc.xref.CONNECT.1">1 2.1</a>, <a href="#rfc.xref.CONNECT.2">C</a></li>4987 <li>DELETE <a href="#rfc.iref.m.6"><b>2.3.6</b></a>, <a href="#rfc.xref.DELETE.1">1 2.1</a></li>4988 <li>GET <a href="#rfc.iref.m.2"><b>2.3.2</b></a>, <a href="#rfc.xref.GET.1">1 2.1</a></li>4989 <li>HEAD <a href="#rfc.iref.m.3"><b>2.3.3</b></a>, <a href="#rfc.xref.HEAD.1">1 2.1</a></li>4990 <li>OPTIONS <a href="#rfc.iref.m.1"><b>2.3.1</b></a>, <a href="#rfc.xref.OPTIONS.1">1 1.6</a>, <a href="#rfc.xref.OPTIONS.2">12.1</a></li>4991 <li>POST <a href="#rfc.iref.m.4"><b>2.3.4</b></a>, <a href="#rfc.xref.POST.1">1 2.1</a>, <a href="#rfc.xref.POST.2">C</a></li>4992 <li>PUT <a href="#rfc.iref.m.5"><b>2.3.5</b></a>, <a href="#rfc.xref.PUT.1">1 2.1</a>, <a href="#rfc.xref.PUT.2">C</a></li>4993 <li>TRACE <a href="#rfc.iref.m.7"><b>2.3.7</b></a>, <a href="#rfc.xref.TRACE.1">1 1.6</a>, <a href="#rfc.xref.TRACE.2">12.1</a>, <a href="#rfc.xref.TRACE.3">13.1</a></li>4981 <li>CONNECT <a href="#rfc.iref.m.8"><b>2.3.8</b></a>, <a href="#rfc.xref.CONNECT.1">11.1</a>, <a href="#rfc.xref.CONNECT.2">C</a></li> 4982 <li>DELETE <a href="#rfc.iref.m.6"><b>2.3.6</b></a>, <a href="#rfc.xref.DELETE.1">11.1</a></li> 4983 <li>GET <a href="#rfc.iref.m.2"><b>2.3.2</b></a>, <a href="#rfc.xref.GET.1">11.1</a></li> 4984 <li>HEAD <a href="#rfc.iref.m.3"><b>2.3.3</b></a>, <a href="#rfc.xref.HEAD.1">11.1</a></li> 4985 <li>OPTIONS <a href="#rfc.iref.m.1"><b>2.3.1</b></a>, <a href="#rfc.xref.OPTIONS.1">10.6</a>, <a href="#rfc.xref.OPTIONS.2">11.1</a></li> 4986 <li>POST <a href="#rfc.iref.m.4"><b>2.3.4</b></a>, <a href="#rfc.xref.POST.1">11.1</a>, <a href="#rfc.xref.POST.2">C</a></li> 4987 <li>PUT <a href="#rfc.iref.m.5"><b>2.3.5</b></a>, <a href="#rfc.xref.PUT.1">11.1</a>, <a href="#rfc.xref.PUT.2">C</a></li> 4988 <li>TRACE <a href="#rfc.iref.m.7"><b>2.3.7</b></a>, <a href="#rfc.xref.TRACE.1">10.6</a>, <a href="#rfc.xref.TRACE.2">11.1</a>, <a href="#rfc.xref.TRACE.3">12.1</a></li> 4994 4989 </ul> 4995 4990 </li> 4996 <li>MIME-Version header field <a href="#rfc.xref.mime-version.1">1 2.3</a>, <a href="#rfc.iref.m.10"><b>A.1</b></a></li>4991 <li>MIME-Version header field <a href="#rfc.xref.mime-version.1">11.3</a>, <a href="#rfc.iref.m.10"><b>A.1</b></a></li> 4997 4992 </ul> 4998 4993 </li> 4999 4994 <li><a id="rfc.index.O" href="#rfc.index.O"><b>O</b></a><ul> 5000 <li>OPTIONS method <a href="#rfc.iref.o.1"><b>2.3.1</b></a>, <a href="#rfc.xref.OPTIONS.1">1 1.6</a>, <a href="#rfc.xref.OPTIONS.2">12.1</a></li>4995 <li>OPTIONS method <a href="#rfc.iref.o.1"><b>2.3.1</b></a>, <a href="#rfc.xref.OPTIONS.1">10.6</a>, <a href="#rfc.xref.OPTIONS.2">11.1</a></li> 5001 4996 </ul> 5002 4997 </li> 5003 4998 <li><a id="rfc.index.P" href="#rfc.index.P"><b>P</b></a><ul> 5004 <li><em>Part1</em> <a href="#rfc.xref.Part1.1">1</a>, <a href="#rfc.xref.Part1.2">1.2</a>, <a href="#rfc.xref.Part1.3">1.3</a>, <a href="#rfc.xref.Part1.4">1.3.1</a>, <a href="#rfc.xref.Part1.5">1.3.1</a>, <a href="#rfc.xref.Part1.6">1.3.1</a>, <a href="#rfc.xref.Part1.7">1.3.1</a>, <a href="#rfc.xref.Part1.8">1.3.1</a>, <a href="#rfc.xref.Part1.9">1.3.1</a>, <a href="#rfc.xref.Part1.10">1.3.1</a>, <a href="#rfc.xref.Part1.11">1.3.2</a>, <a href="#rfc.xref.Part1.12">1.3.2</a>, <a href="#rfc.xref.Part1.13">1.3.2</a>, <a href="#rfc.xref.Part1.14">1.3.2</a>, <a href="#rfc.xref.Part1.15">2</a>, <a href="#rfc.xref.Part1.16">2.2.1</a>, <a href="#rfc.xref.Part1.17">2.3.1</a>, <a href="#rfc.xref.Part1.18">2.3.7</a>, <a href="#rfc.xref.Part1.19">2.3.7</a>, <a href="#rfc.xref.Part1.20">2.3.8</a>, <a href="#rfc.xref.Part1.21">3</a>, <a href="#rfc.xref.Part1.22">3.1</a>, <a href="#rfc.xref.Part1.23">3.1</a>, <a href="#rfc.xref.Part1.24">3.1</a>, <a href="#rfc.xref.Part1.25">3.1</a>, <a href="#rfc.xref.Part1.26">3.1</a>, <a href="#rfc.xref.Part1.27">3.2</a>, <a href="#rfc.xref.Part1.28">3.2</a>, <a href="#rfc.xref.Part1.29">3.3</a>, <a href="#rfc.xref.Part1.30">4.3.1</a>, <a href="#rfc.xref.Part1.31">4.3.2</a>, <a href="#rfc.xref.Part1.32">4.4.4</a>, <a href="#rfc.xref.Part1.33">4.4.6</a>, <a href="#rfc.xref.Part1.34">4.6.15</a>, <a href="#rfc.xref.Part1.35">4.7.6</a>, <a href="#rfc.xref.Part1.36">5</a>, <a href="#rfc.xref.Part1.37">5.1</a>, <a href="#rfc.xref.Part1.38"> 7.2</a>, <a href="#rfc.xref.Part1.39">7.2</a>, <a href="#rfc.xref.Part1.40">7.2</a>, <a href="#rfc.xref.Part1.41">7.2.1</a>, <a href="#rfc.xref.Part1.42">7.2.1</a>, <a href="#rfc.xref.Part1.43">8.1</a>, <a href="#rfc.xref.Part1.44">8.2</a>, <a href="#rfc.xref.Part1.45">11.3</a>, <a href="#rfc.xref.Part1.46">11.9</a>, <a href="#rfc.xref.Part1.47">11.9</a>, <a href="#rfc.xref.Part1.48">11.10</a>, <a href="#rfc.xref.Part1.49">11.17</a>, <a href="#rfc.xref.Part1.50">12.4</a>, <a href="#rfc.xref.Part1.51">12.4</a>, <a href="#rfc.xref.Part1.52">12.4</a>, <a href="#rfc.xref.Part1.53">14</a>, <a href="#Part1"><b>15.1</b></a>, <a href="#rfc.xref.Part1.54">A.6</a>, <a href="#rfc.xref.Part1.55">C</a><ul>4999 <li><em>Part1</em> <a href="#rfc.xref.Part1.1">1</a>, <a href="#rfc.xref.Part1.2">1.2</a>, <a href="#rfc.xref.Part1.3">1.3</a>, <a href="#rfc.xref.Part1.4">1.3.1</a>, <a href="#rfc.xref.Part1.5">1.3.1</a>, <a href="#rfc.xref.Part1.6">1.3.1</a>, <a href="#rfc.xref.Part1.7">1.3.1</a>, <a href="#rfc.xref.Part1.8">1.3.1</a>, <a href="#rfc.xref.Part1.9">1.3.1</a>, <a href="#rfc.xref.Part1.10">1.3.1</a>, <a href="#rfc.xref.Part1.11">1.3.2</a>, <a href="#rfc.xref.Part1.12">1.3.2</a>, <a href="#rfc.xref.Part1.13">1.3.2</a>, <a href="#rfc.xref.Part1.14">1.3.2</a>, <a href="#rfc.xref.Part1.15">2</a>, <a href="#rfc.xref.Part1.16">2.2.1</a>, <a href="#rfc.xref.Part1.17">2.3.1</a>, <a href="#rfc.xref.Part1.18">2.3.7</a>, <a href="#rfc.xref.Part1.19">2.3.7</a>, <a href="#rfc.xref.Part1.20">2.3.8</a>, <a href="#rfc.xref.Part1.21">3</a>, <a href="#rfc.xref.Part1.22">3.1</a>, <a href="#rfc.xref.Part1.23">3.1</a>, <a href="#rfc.xref.Part1.24">3.1</a>, <a href="#rfc.xref.Part1.25">3.1</a>, <a href="#rfc.xref.Part1.26">3.1</a>, <a href="#rfc.xref.Part1.27">3.2</a>, <a href="#rfc.xref.Part1.28">3.2</a>, <a href="#rfc.xref.Part1.29">3.3</a>, <a href="#rfc.xref.Part1.30">4.3.1</a>, <a href="#rfc.xref.Part1.31">4.3.2</a>, <a href="#rfc.xref.Part1.32">4.4.4</a>, <a href="#rfc.xref.Part1.33">4.4.6</a>, <a href="#rfc.xref.Part1.34">4.6.15</a>, <a href="#rfc.xref.Part1.35">4.7.6</a>, <a href="#rfc.xref.Part1.36">5</a>, <a href="#rfc.xref.Part1.37">5.1</a>, <a href="#rfc.xref.Part1.38">6.4</a>, <a href="#rfc.xref.Part1.39">6.4</a>, <a href="#rfc.xref.Part1.40">6.4</a>, <a href="#rfc.xref.Part1.41">6.4.1</a>, <a href="#rfc.xref.Part1.42">6.4.1</a>, <a href="#rfc.xref.Part1.43">7.1</a>, <a href="#rfc.xref.Part1.44">7.2</a>, <a href="#rfc.xref.Part1.45">10.3</a>, <a href="#rfc.xref.Part1.46">10.9</a>, <a href="#rfc.xref.Part1.47">10.9</a>, <a href="#rfc.xref.Part1.48">10.10</a>, <a href="#rfc.xref.Part1.49">10.17</a>, <a href="#rfc.xref.Part1.50">11.4</a>, <a href="#rfc.xref.Part1.51">11.4</a>, <a href="#rfc.xref.Part1.52">11.4</a>, <a href="#rfc.xref.Part1.53">13</a>, <a href="#Part1"><b>14.1</b></a>, <a href="#rfc.xref.Part1.54">A.6</a>, <a href="#rfc.xref.Part1.55">C</a><ul> 5005 5000 <li><em>Section 1.2</em> <a href="#rfc.xref.Part1.3">1.3</a></li> 5006 5001 <li><em>Section 2</em> <a href="#rfc.xref.Part1.2">1.2</a></li> … … 5009 5004 <li><em>Section 2.7</em> <a href="#rfc.xref.Part1.11">1.3.2</a>, <a href="#rfc.xref.Part1.13">1.3.2</a>, <a href="#rfc.xref.Part1.14">1.3.2</a></li> 5010 5005 <li><em>Section 3.2.1</em> <a href="#rfc.xref.Part1.5">1.3.1</a>, <a href="#rfc.xref.Part1.6">1.3.1</a>, <a href="#rfc.xref.Part1.7">1.3.1</a></li> 5011 <li><em>Section 3.2</em> <a href="#rfc.xref.Part1.21">3</a>, <a href="#rfc.xref.Part1.24">3.1</a>, <a href="#rfc.xref.Part1.46">1 1.9</a>, <a href="#rfc.xref.Part1.48">11.10</a></li>5006 <li><em>Section 3.2</em> <a href="#rfc.xref.Part1.21">3</a>, <a href="#rfc.xref.Part1.24">3.1</a>, <a href="#rfc.xref.Part1.46">10.9</a>, <a href="#rfc.xref.Part1.48">10.10</a></li> 5012 5007 <li><em>Section 3.2.4</em> <a href="#rfc.xref.Part1.8">1.3.1</a>, <a href="#rfc.xref.Part1.9">1.3.1</a>, <a href="#rfc.xref.Part1.10">1.3.1</a>, <a href="#rfc.xref.Part1.12">1.3.2</a>, <a href="#rfc.xref.Part1.23">3.1</a></li> 5013 5008 <li><em>Section 3.2.5</em> <a href="#rfc.xref.Part1.22">3.1</a></li> 5014 <li><em>Section 3.3</em> <a href="#rfc.xref.Part1.16">2.2.1</a>, <a href="#rfc.xref.Part1.33">4.4.6</a>, <a href="#rfc.xref.Part1.36">5</a>, <a href="#rfc.xref.Part1.44"> 8.2</a></li>5009 <li><em>Section 3.3</em> <a href="#rfc.xref.Part1.16">2.2.1</a>, <a href="#rfc.xref.Part1.33">4.4.6</a>, <a href="#rfc.xref.Part1.36">5</a>, <a href="#rfc.xref.Part1.44">7.2</a></li> 5015 5010 <li><em>Section 3.3.1</em> <a href="#rfc.xref.Part1.54">A.6</a></li> 5016 <li><em>Section 3.3.2</em> <a href="#rfc.xref.Part1.43"> 8.1</a></li>5017 <li><em>Section 4</em> <a href="#rfc.xref.Part1.41"> 7.2.1</a></li>5011 <li><em>Section 3.3.2</em> <a href="#rfc.xref.Part1.43">7.1</a></li> 5012 <li><em>Section 4</em> <a href="#rfc.xref.Part1.41">6.4.1</a></li> 5018 5013 <li><em>Section 4.1</em> <a href="#rfc.xref.Part1.26">3.1</a></li> 5019 <li><em>Section 4.2.1</em> <a href="#rfc.xref.Part1.38"> 7.2</a>, <a href="#rfc.xref.Part1.50">12.4</a></li>5020 <li><em>Section 4.2</em> <a href="#rfc.xref.Part1.42"> 7.2.1</a></li>5021 <li><em>Section 4.2.2</em> <a href="#rfc.xref.Part1.39"> 7.2</a>, <a href="#rfc.xref.Part1.51">12.4</a></li>5022 <li><em>Section 4.2.3</em> <a href="#rfc.xref.Part1.40"> 7.2</a>, <a href="#rfc.xref.Part1.52">12.4</a></li>5014 <li><em>Section 4.2.1</em> <a href="#rfc.xref.Part1.38">6.4</a>, <a href="#rfc.xref.Part1.50">11.4</a></li> 5015 <li><em>Section 4.2</em> <a href="#rfc.xref.Part1.42">6.4.1</a></li> 5016 <li><em>Section 4.2.2</em> <a href="#rfc.xref.Part1.39">6.4</a>, <a href="#rfc.xref.Part1.51">11.4</a></li> 5017 <li><em>Section 4.2.3</em> <a href="#rfc.xref.Part1.40">6.4</a>, <a href="#rfc.xref.Part1.52">11.4</a></li> 5023 5018 <li><em>Section 4.3</em> <a href="#rfc.xref.Part1.28">3.2</a></li> 5024 5019 <li><em>Section 5.3</em> <a href="#rfc.xref.Part1.17">2.3.1</a>, <a href="#rfc.xref.Part1.20">2.3.8</a></li> 5025 5020 <li><em>Section 5.4</em> <a href="#rfc.xref.Part1.27">3.2</a></li> 5026 <li><em>Section 5.5</em> <a href="#rfc.xref.Part1.15">2</a>, <a href="#rfc.xref.Part1.29">3.3</a>, <a href="#rfc.xref.Part1.37">5.1</a>, <a href="#rfc.xref.Part1.49">1 1.17</a></li>5021 <li><em>Section 5.5</em> <a href="#rfc.xref.Part1.15">2</a>, <a href="#rfc.xref.Part1.29">3.3</a>, <a href="#rfc.xref.Part1.37">5.1</a>, <a href="#rfc.xref.Part1.49">10.17</a></li> 5027 5022 <li><em>Section 6.1</em> <a href="#rfc.xref.Part1.25">3.1</a></li> 5028 <li><em>Section 6.2</em> <a href="#rfc.xref.Part1.18">2.3.7</a>, <a href="#rfc.xref.Part1.47">1 1.9</a>, <a href="#rfc.xref.Part1.55">C</a></li>5029 <li><em>Section 6.4.3</em> <a href="#rfc.xref.Part1.30">4.3.1</a>, <a href="#rfc.xref.Part1.45">1 1.3</a></li>5023 <li><em>Section 6.2</em> <a href="#rfc.xref.Part1.18">2.3.7</a>, <a href="#rfc.xref.Part1.47">10.9</a>, <a href="#rfc.xref.Part1.55">C</a></li> 5024 <li><em>Section 6.4.3</em> <a href="#rfc.xref.Part1.30">4.3.1</a>, <a href="#rfc.xref.Part1.45">10.3</a></li> 5030 5025 <li><em>Section 6.5</em> <a href="#rfc.xref.Part1.31">4.3.2</a>, <a href="#rfc.xref.Part1.34">4.6.15</a></li> 5031 5026 <li><em>Section 7.3.1</em> <a href="#rfc.xref.Part1.19">2.3.7</a></li> 5032 <li><em>Section 9</em> <a href="#rfc.xref.Part1.53">1 4</a></li>5027 <li><em>Section 9</em> <a href="#rfc.xref.Part1.53">13</a></li> 5033 5028 </ul> 5034 5029 </li> 5035 <li><em>Part4</em> <a href="#rfc.xref.Part4.1">3.2</a>, <a href="#rfc.xref.Part4.2">3.2</a>, <a href="#rfc.xref.Part4.3">3.2</a>, <a href="#rfc.xref.Part4.4">3.2</a>, <a href="#rfc.xref.Part4.5">3.3</a>, <a href="#rfc.xref.Part4.6">4.1</a>, <a href="#rfc.xref.Part4.7">4.1</a>, <a href="#rfc.xref.Part4.8">4.1</a>, <a href="#rfc.xref.Part4.9">4.4.2</a>, <a href="#rfc.xref.Part4.10">4.5</a>, <a href="#rfc.xref.Part4.11"> 9.1</a>, <a href="#rfc.xref.Part4.12">9.1</a>, <a href="#Part4"><b>15.1</b></a>, <a href="#rfc.xref.Part4.13">E.2</a><ul>5036 <li><em>Section 2.2</em> <a href="#rfc.xref.Part4.12"> 9.1</a></li>5037 <li><em>Section 2.3</em> <a href="#rfc.xref.Part4.5">3.3</a>, <a href="#rfc.xref.Part4.9">4.4.2</a>, <a href="#rfc.xref.Part4.11"> 9.1</a></li>5030 <li><em>Part4</em> <a href="#rfc.xref.Part4.1">3.2</a>, <a href="#rfc.xref.Part4.2">3.2</a>, <a href="#rfc.xref.Part4.3">3.2</a>, <a href="#rfc.xref.Part4.4">3.2</a>, <a href="#rfc.xref.Part4.5">3.3</a>, <a href="#rfc.xref.Part4.6">4.1</a>, <a href="#rfc.xref.Part4.7">4.1</a>, <a href="#rfc.xref.Part4.8">4.1</a>, <a href="#rfc.xref.Part4.9">4.4.2</a>, <a href="#rfc.xref.Part4.10">4.5</a>, <a href="#rfc.xref.Part4.11">8.1</a>, <a href="#rfc.xref.Part4.12">8.1</a>, <a href="#Part4"><b>14.1</b></a>, <a href="#rfc.xref.Part4.13">E.2</a><ul> 5031 <li><em>Section 2.2</em> <a href="#rfc.xref.Part4.12">8.1</a></li> 5032 <li><em>Section 2.3</em> <a href="#rfc.xref.Part4.5">3.3</a>, <a href="#rfc.xref.Part4.9">4.4.2</a>, <a href="#rfc.xref.Part4.11">8.1</a></li> 5038 5033 <li><em>Section 3.1</em> <a href="#rfc.xref.Part4.1">3.2</a></li> 5039 5034 <li><em>Section 3.2</em> <a href="#rfc.xref.Part4.3">3.2</a></li> … … 5045 5040 </ul> 5046 5041 </li> 5047 <li><em>Part5</em> <a href="#rfc.xref.Part5.1">2.3.2</a>, <a href="#rfc.xref.Part5.2">3.2</a>, <a href="#rfc.xref.Part5.3">3.2</a>, <a href="#rfc.xref.Part5.4">3.3</a>, <a href="#rfc.xref.Part5.5">4.1</a>, <a href="#rfc.xref.Part5.6">4.1</a>, <a href="#rfc.xref.Part5.7">4.1</a>, <a href="#rfc.xref.Part5.8"> 8.1</a>, <a href="#Part5"><b>15.1</b></a><ul>5042 <li><em>Part5</em> <a href="#rfc.xref.Part5.1">2.3.2</a>, <a href="#rfc.xref.Part5.2">3.2</a>, <a href="#rfc.xref.Part5.3">3.2</a>, <a href="#rfc.xref.Part5.4">3.3</a>, <a href="#rfc.xref.Part5.5">4.1</a>, <a href="#rfc.xref.Part5.6">4.1</a>, <a href="#rfc.xref.Part5.7">4.1</a>, <a href="#rfc.xref.Part5.8">7.1</a>, <a href="#Part5"><b>14.1</b></a><ul> 5048 5043 <li><em>Section 3</em> <a href="#rfc.xref.Part5.5">4.1</a></li> 5049 5044 <li><em>Section 3.1</em> <a href="#rfc.xref.Part5.6">4.1</a></li> 5050 5045 <li><em>Section 3.2</em> <a href="#rfc.xref.Part5.7">4.1</a></li> 5051 5046 <li><em>Section 5.1</em> <a href="#rfc.xref.Part5.4">3.3</a></li> 5052 <li><em>Section 5.2</em> <a href="#rfc.xref.Part5.8"> 8.1</a></li>5047 <li><em>Section 5.2</em> <a href="#rfc.xref.Part5.8">7.1</a></li> 5053 5048 <li><em>Section 5.3</em> <a href="#rfc.xref.Part5.2">3.2</a></li> 5054 5049 <li><em>Section 5.4</em> <a href="#rfc.xref.Part5.1">2.3.2</a>, <a href="#rfc.xref.Part5.3">3.2</a></li> 5055 5050 </ul> 5056 5051 </li> 5057 <li><em>Part6</em> <a href="#rfc.xref.Part6.1">2.2.1</a>, <a href="#rfc.xref.Part6.2">2.3.2</a>, <a href="#rfc.xref.Part6.3">2.3.3</a>, <a href="#rfc.xref.Part6.4">2.3.4</a>, <a href="#rfc.xref.Part6.5">2.3.5</a>, <a href="#rfc.xref.Part6.6">2.3.6</a>, <a href="#rfc.xref.Part6.7">3.1</a>, <a href="#rfc.xref.Part6.8">3.3</a>, <a href="#rfc.xref.Part6.9">3.3</a>, <a href="#rfc.xref.Part6.10">4.2.1</a>, <a href="#rfc.xref.Part6.11">4.4.1</a>, <a href="#rfc.xref.Part6.12">4.4.4</a>, <a href="#rfc.xref.Part6.13">4.4.4</a>, <a href="#rfc.xref.Part6.14">4.4.4</a>, <a href="#rfc.xref.Part6.15">4.5.1</a>, <a href="#rfc.xref.Part6.16">4.5.2</a>, <a href="#rfc.xref.Part6.17">4.6.9</a>, <a href="#rfc.xref.Part6.18"> 9.1</a>, <a href="#rfc.xref.Part6.19">10.1</a>, <a href="#Part6"><b>15.1</b></a><ul>5052 <li><em>Part6</em> <a href="#rfc.xref.Part6.1">2.2.1</a>, <a href="#rfc.xref.Part6.2">2.3.2</a>, <a href="#rfc.xref.Part6.3">2.3.3</a>, <a href="#rfc.xref.Part6.4">2.3.4</a>, <a href="#rfc.xref.Part6.5">2.3.5</a>, <a href="#rfc.xref.Part6.6">2.3.6</a>, <a href="#rfc.xref.Part6.7">3.1</a>, <a href="#rfc.xref.Part6.8">3.3</a>, <a href="#rfc.xref.Part6.9">3.3</a>, <a href="#rfc.xref.Part6.10">4.2.1</a>, <a href="#rfc.xref.Part6.11">4.4.1</a>, <a href="#rfc.xref.Part6.12">4.4.4</a>, <a href="#rfc.xref.Part6.13">4.4.4</a>, <a href="#rfc.xref.Part6.14">4.4.4</a>, <a href="#rfc.xref.Part6.15">4.5.1</a>, <a href="#rfc.xref.Part6.16">4.5.2</a>, <a href="#rfc.xref.Part6.17">4.6.9</a>, <a href="#rfc.xref.Part6.18">8.1</a>, <a href="#rfc.xref.Part6.19">9.1</a>, <a href="#Part6"><b>14.1</b></a><ul> 5058 5053 <li><em>Section 2.3.1</em> <a href="#rfc.xref.Part6.4">2.3.4</a></li> 5059 5054 <li><em>Section 2.3.1.1</em> <a href="#rfc.xref.Part6.11">4.4.1</a>, <a href="#rfc.xref.Part6.14">4.4.4</a>, <a href="#rfc.xref.Part6.15">4.5.1</a>, <a href="#rfc.xref.Part6.16">4.5.2</a>, <a href="#rfc.xref.Part6.17">4.6.9</a></li> … … 5062 5057 <li><em>Section 3.1</em> <a href="#rfc.xref.Part6.8">3.3</a></li> 5063 5058 <li><em>Section 3.2</em> <a href="#rfc.xref.Part6.12">4.4.4</a></li> 5064 <li><em>Section 3.3</em> <a href="#rfc.xref.Part6.18"> 9.1</a></li>5065 <li><em>Section 3.5</em> <a href="#rfc.xref.Part6.9">3.3</a>, <a href="#rfc.xref.Part6.19"> 10.1</a></li>5059 <li><em>Section 3.3</em> <a href="#rfc.xref.Part6.18">8.1</a></li> 5060 <li><em>Section 3.5</em> <a href="#rfc.xref.Part6.9">3.3</a>, <a href="#rfc.xref.Part6.19">9.1</a></li> 5066 5061 <li><em>Section 3.6</em> <a href="#rfc.xref.Part6.13">4.4.4</a></li> 5067 5062 </ul> 5068 5063 </li> 5069 <li><em>Part7</em> <a href="#rfc.xref.Part7.1">3.2</a>, <a href="#rfc.xref.Part7.2">3.2</a>, <a href="#rfc.xref.Part7.3">3.3</a>, <a href="#rfc.xref.Part7.4">3.3</a>, <a href="#rfc.xref.Part7.5">4.1</a>, <a href="#rfc.xref.Part7.6">4.1</a>, <a href="#rfc.xref.Part7.7">4.1</a>, <a href="#Part7"><b>1 5.1</b></a><ul>5064 <li><em>Part7</em> <a href="#rfc.xref.Part7.1">3.2</a>, <a href="#rfc.xref.Part7.2">3.2</a>, <a href="#rfc.xref.Part7.3">3.3</a>, <a href="#rfc.xref.Part7.4">3.3</a>, <a href="#rfc.xref.Part7.5">4.1</a>, <a href="#rfc.xref.Part7.6">4.1</a>, <a href="#rfc.xref.Part7.7">4.1</a>, <a href="#Part7"><b>14.1</b></a><ul> 5070 5065 <li><em>Section 3</em> <a href="#rfc.xref.Part7.5">4.1</a></li> 5071 5066 <li><em>Section 3.1</em> <a href="#rfc.xref.Part7.6">4.1</a></li> … … 5077 5072 </ul> 5078 5073 </li> 5079 <li>payload <a href="#rfc.iref.p.3"> 8</a></li>5080 <li>POST method <a href="#rfc.iref.p.1"><b>2.3.4</b></a>, <a href="#rfc.xref.POST.1">1 2.1</a>, <a href="#rfc.xref.POST.2">C</a></li>5081 <li>PUT method <a href="#rfc.iref.p.2"><b>2.3.5</b></a>, <a href="#rfc.xref.PUT.1">1 2.1</a>, <a href="#rfc.xref.PUT.2">C</a></li>5074 <li>payload <a href="#rfc.iref.p.3">7</a></li> 5075 <li>POST method <a href="#rfc.iref.p.1"><b>2.3.4</b></a>, <a href="#rfc.xref.POST.1">11.1</a>, <a href="#rfc.xref.POST.2">C</a></li> 5076 <li>PUT method <a href="#rfc.iref.p.2"><b>2.3.5</b></a>, <a href="#rfc.xref.PUT.1">11.1</a>, <a href="#rfc.xref.PUT.2">C</a></li> 5082 5077 </ul> 5083 5078 </li> 5084 5079 <li><a id="rfc.index.R" href="#rfc.index.R"><b>R</b></a><ul> 5085 <li>Referer header field <a href="#rfc.xref.header.referer.1">3.2</a>, <a href="#rfc.iref.r.2"><b>1 1.7</b></a>, <a href="#rfc.xref.header.referer.2">12.3</a>, <a href="#rfc.xref.header.referer.3">C</a></li>5086 <li>representation <a href="#rfc.iref.r.1"> 9</a></li>5087 <li>Retry-After header field <a href="#rfc.xref.header.retry-after.1">3.3</a>, <a href="#rfc.xref.header.retry-after.2">4.7.4</a>, <a href="#rfc.iref.r.3"><b>1 1.8</b></a>, <a href="#rfc.xref.header.retry-after.3">12.3</a></li>5088 <li><em>RFC1123</em> <a href="#rfc.xref.RFC1123.1">6.1</a>, <a href="#rfc.xref.RFC1123.2">6.1</a>, <a href="#RFC1123"><b>1 5.2</b></a><ul>5080 <li>Referer header field <a href="#rfc.xref.header.referer.1">3.2</a>, <a href="#rfc.iref.r.2"><b>10.7</b></a>, <a href="#rfc.xref.header.referer.2">11.3</a>, <a href="#rfc.xref.header.referer.3">C</a></li> 5081 <li>representation <a href="#rfc.iref.r.1">8</a></li> 5082 <li>Retry-After header field <a href="#rfc.xref.header.retry-after.1">3.3</a>, <a href="#rfc.xref.header.retry-after.2">4.7.4</a>, <a href="#rfc.iref.r.3"><b>10.8</b></a>, <a href="#rfc.xref.header.retry-after.3">11.3</a></li> 5083 <li><em>RFC1123</em> <a href="#rfc.xref.RFC1123.1">6.1</a>, <a href="#rfc.xref.RFC1123.2">6.1</a>, <a href="#RFC1123"><b>14.2</b></a><ul> 5089 5084 <li><em>Section 5.2.14</em> <a href="#rfc.xref.RFC1123.2">6.1</a></li> 5090 5085 </ul> 5091 5086 </li> 5092 <li><em>RFC1945</em> <a href="#rfc.xref.RFC1945.1">4.5</a>, <a href="#RFC1945"><b>1 5.2</b></a>, <a href="#rfc.xref.RFC1945.2">B</a><ul>5087 <li><em>RFC1945</em> <a href="#rfc.xref.RFC1945.1">4.5</a>, <a href="#RFC1945"><b>14.2</b></a>, <a href="#rfc.xref.RFC1945.2">B</a><ul> 5093 5088 <li><em>Section 9.3</em> <a href="#rfc.xref.RFC1945.1">4.5</a></li> 5094 5089 </ul> 5095 5090 </li> 5096 <li><em>RFC1950</em> <a href="#rfc.xref.RFC1950.1">1 2.4</a>, <a href="#RFC1950"><b>15.1</b></a></li>5097 <li><em>RFC1951</em> <a href="#rfc.xref.RFC1951.1">1 2.4</a>, <a href="#RFC1951"><b>15.1</b></a></li>5098 <li><em>RFC1952</em> <a href="#rfc.xref.RFC1952.1">1 2.4</a>, <a href="#RFC1952"><b>15.1</b></a></li>5099 <li><em>RFC2045</em> <a href="#RFC2045"><b>1 5.1</b></a>, <a href="#rfc.xref.RFC2045.1">A</a>, <a href="#rfc.xref.RFC2045.2">A.1</a></li>5100 <li><em>RFC2046</em> <a href="#rfc.xref.RFC2046.1"> 7.3</a>, <a href="#rfc.xref.RFC2046.2">7.3.2</a>, <a href="#rfc.xref.RFC2046.3">9.2</a>, <a href="#RFC2046"><b>15.1</b></a>, <a href="#rfc.xref.RFC2046.4">A.2</a><ul>5101 <li><em>Section 4.5.1</em> <a href="#rfc.xref.RFC2046.3"> 9.2</a></li>5102 <li><em>Section 5.1.1</em> <a href="#rfc.xref.RFC2046.2"> 7.3.2</a></li>5091 <li><em>RFC1950</em> <a href="#rfc.xref.RFC1950.1">11.4</a>, <a href="#RFC1950"><b>14.1</b></a></li> 5092 <li><em>RFC1951</em> <a href="#rfc.xref.RFC1951.1">11.4</a>, <a href="#RFC1951"><b>14.1</b></a></li> 5093 <li><em>RFC1952</em> <a href="#rfc.xref.RFC1952.1">11.4</a>, <a href="#RFC1952"><b>14.1</b></a></li> 5094 <li><em>RFC2045</em> <a href="#RFC2045"><b>14.1</b></a>, <a href="#rfc.xref.RFC2045.1">A</a>, <a href="#rfc.xref.RFC2045.2">A.1</a></li> 5095 <li><em>RFC2046</em> <a href="#rfc.xref.RFC2046.1">6.5</a>, <a href="#rfc.xref.RFC2046.2">6.5.2</a>, <a href="#rfc.xref.RFC2046.3">8.2</a>, <a href="#RFC2046"><b>14.1</b></a>, <a href="#rfc.xref.RFC2046.4">A.2</a><ul> 5096 <li><em>Section 4.5.1</em> <a href="#rfc.xref.RFC2046.3">8.2</a></li> 5097 <li><em>Section 5.1.1</em> <a href="#rfc.xref.RFC2046.2">6.5.2</a></li> 5103 5098 </ul> 5104 5099 </li> 5105 <li><em>RFC2049</em> <a href="#RFC2049"><b>1 5.2</b></a>, <a href="#rfc.xref.RFC2049.1">A.2</a><ul>5100 <li><em>RFC2049</em> <a href="#RFC2049"><b>14.2</b></a>, <a href="#rfc.xref.RFC2049.1">A.2</a><ul> 5106 5101 <li><em>Section 4</em> <a href="#rfc.xref.RFC2049.1">A.2</a></li> 5107 5102 </ul> 5108 5103 </li> 5109 <li><em>RFC2068</em> <a href="#rfc.xref.RFC2068.1">4.5</a>, <a href="#rfc.xref.RFC2068.2">4.5</a>, <a href="#RFC2068"><b>1 5.2</b></a>, <a href="#rfc.xref.RFC2068.3">B</a><ul>5104 <li><em>RFC2068</em> <a href="#rfc.xref.RFC2068.1">4.5</a>, <a href="#rfc.xref.RFC2068.2">4.5</a>, <a href="#RFC2068"><b>14.2</b></a>, <a href="#rfc.xref.RFC2068.3">B</a><ul> 5110 5105 <li><em>Section 10.3</em> <a href="#rfc.xref.RFC2068.2">4.5</a></li> 5111 5106 <li><em>Section 10.3.4</em> <a href="#rfc.xref.RFC2068.1">4.5</a></li> 5112 5107 </ul> 5113 5108 </li> 5114 <li><em>RFC2076</em> <a href="#RFC2076"><b>1 5.2</b></a>, <a href="#rfc.xref.RFC2076.1">B</a></li>5115 <li><em>RFC2119</em> <a href="#rfc.xref.RFC2119.1">1.2</a>, <a href="#RFC2119"><b>1 5.1</b></a></li>5116 <li><em>RFC2277</em> <a href="#rfc.xref.RFC2277.1"> 7.1</a>, <a href="#RFC2277"><b>15.2</b></a></li>5117 <li><em>RFC2295</em> <a href="#rfc.xref.RFC2295.1"> 10</a>, <a href="#RFC2295"><b>15.1</b></a></li>5118 <li><em>RFC2388</em> <a href="#rfc.xref.RFC2388.1"> 7.3.2</a>, <a href="#RFC2388"><b>15.2</b></a></li>5119 <li><em>RFC2557</em> <a href="#rfc.xref.RFC2557.1">1 1.17</a>, <a href="#RFC2557"><b>15.2</b></a>, <a href="#rfc.xref.RFC2557.2">A.7</a><ul>5120 <li><em>Section 4</em> <a href="#rfc.xref.RFC2557.1">1 1.17</a></li>5109 <li><em>RFC2076</em> <a href="#RFC2076"><b>14.2</b></a>, <a href="#rfc.xref.RFC2076.1">B</a></li> 5110 <li><em>RFC2119</em> <a href="#rfc.xref.RFC2119.1">1.2</a>, <a href="#RFC2119"><b>14.1</b></a></li> 5111 <li><em>RFC2277</em> <a href="#rfc.xref.RFC2277.1">6.3</a>, <a href="#RFC2277"><b>14.2</b></a></li> 5112 <li><em>RFC2295</em> <a href="#rfc.xref.RFC2295.1">9</a>, <a href="#RFC2295"><b>14.1</b></a></li> 5113 <li><em>RFC2388</em> <a href="#rfc.xref.RFC2388.1">6.5.2</a>, <a href="#RFC2388"><b>14.2</b></a></li> 5114 <li><em>RFC2557</em> <a href="#rfc.xref.RFC2557.1">10.17</a>, <a href="#RFC2557"><b>14.2</b></a>, <a href="#rfc.xref.RFC2557.2">A.7</a><ul> 5115 <li><em>Section 4</em> <a href="#rfc.xref.RFC2557.1">10.17</a></li> 5121 5116 </ul> 5122 5117 </li> 5123 <li><em>RFC2616</em> <a href="#rfc.xref.RFC2616.1">1</a>, <a href="#rfc.xref.RFC2616.2">4.5</a>, <a href="#rfc.xref.RFC2616.3">1 1.14</a>, <a href="#RFC2616"><b>15.2</b></a>, <a href="#rfc.xref.RFC2616.4">E.1</a><ul>5118 <li><em>RFC2616</em> <a href="#rfc.xref.RFC2616.1">1</a>, <a href="#rfc.xref.RFC2616.2">4.5</a>, <a href="#rfc.xref.RFC2616.3">10.14</a>, <a href="#RFC2616"><b>14.2</b></a>, <a href="#rfc.xref.RFC2616.4">E.1</a><ul> 5124 5119 <li><em>Section 10.3.8</em> <a href="#rfc.xref.RFC2616.2">4.5</a></li> 5125 <li><em>Section 14.4</em> <a href="#rfc.xref.RFC2616.3">1 1.14</a></li>5120 <li><em>Section 14.4</em> <a href="#rfc.xref.RFC2616.3">10.14</a></li> 5126 5121 </ul> 5127 5122 </li> 5128 <li><em>RFC2817</em> <a href="#rfc.xref.RFC2817.1">1 2.2</a>, <a href="#RFC2817"><b>15.2</b></a>, <a href="#rfc.xref.RFC2817.2">C</a>, <a href="#rfc.xref.RFC2817.3">C</a>, <a href="#rfc.xref.RFC2817.4">C</a><ul>5129 <li><em>Section 7.1</em> <a href="#rfc.xref.RFC2817.1">1 2.2</a>, <a href="#rfc.xref.RFC2817.3">C</a></li>5123 <li><em>RFC2817</em> <a href="#rfc.xref.RFC2817.1">11.2</a>, <a href="#RFC2817"><b>14.2</b></a>, <a href="#rfc.xref.RFC2817.2">C</a>, <a href="#rfc.xref.RFC2817.3">C</a>, <a href="#rfc.xref.RFC2817.4">C</a><ul> 5124 <li><em>Section 7.1</em> <a href="#rfc.xref.RFC2817.1">11.2</a>, <a href="#rfc.xref.RFC2817.3">C</a></li> 5130 5125 </ul> 5131 5126 </li> 5132 <li><em>RFC3629</em> <a href="#rfc.xref.RFC3629.1"> 7.1</a>, <a href="#RFC3629"><b>15.2</b></a></li>5133 <li><em>RFC3864</em> <a href="#rfc.xref.RFC3864.1">3.1</a>, <a href="#rfc.xref.RFC3864.2">3.1</a>, <a href="#rfc.xref.RFC3864.3">1 2.3</a>, <a href="#RFC3864"><b>15.2</b></a><ul>5127 <li><em>RFC3629</em> <a href="#rfc.xref.RFC3629.1">6.3</a>, <a href="#RFC3629"><b>14.2</b></a></li> 5128 <li><em>RFC3864</em> <a href="#rfc.xref.RFC3864.1">3.1</a>, <a href="#rfc.xref.RFC3864.2">3.1</a>, <a href="#rfc.xref.RFC3864.3">11.3</a>, <a href="#RFC3864"><b>14.2</b></a><ul> 5134 5129 <li><em>Section 4.1</em> <a href="#rfc.xref.RFC3864.2">3.1</a></li> 5135 5130 </ul> 5136 5131 </li> 5137 <li><em>RFC3986</em> <a href="#rfc.xref.RFC3986.1">1 1.5</a>, <a href="#rfc.xref.RFC3986.2">11.5</a>, <a href="#RFC3986"><b>15.1</b></a><ul>5138 <li><em>Section 4.2</em> <a href="#rfc.xref.RFC3986.1">1 1.5</a></li>5139 <li><em>Section 5</em> <a href="#rfc.xref.RFC3986.2">1 1.5</a></li>5132 <li><em>RFC3986</em> <a href="#rfc.xref.RFC3986.1">10.5</a>, <a href="#rfc.xref.RFC3986.2">10.5</a>, <a href="#RFC3986"><b>14.1</b></a><ul> 5133 <li><em>Section 4.2</em> <a href="#rfc.xref.RFC3986.1">10.5</a></li> 5134 <li><em>Section 5</em> <a href="#rfc.xref.RFC3986.2">10.5</a></li> 5140 5135 </ul> 5141 5136 </li> 5142 <li><em>RFC4288</em> <a href="#rfc.xref.RFC4288.1"> 7.3</a>, <a href="#RFC4288"><b>15.1</b></a></li>5143 <li><em>RFC4647</em> <a href="#rfc.xref.RFC4647.1">1 1.14</a>, <a href="#rfc.xref.RFC4647.2">11.14</a>, <a href="#rfc.xref.RFC4647.3">11.14</a>, <a href="#rfc.xref.RFC4647.4">11.14</a>, <a href="#RFC4647"><b>15.1</b></a><ul>5144 <li><em>Section 2.1</em> <a href="#rfc.xref.RFC4647.1">1 1.14</a></li>5145 <li><em>Section 2.3</em> <a href="#rfc.xref.RFC4647.2">1 1.14</a></li>5146 <li><em>Section 3</em> <a href="#rfc.xref.RFC4647.3">1 1.14</a></li>5147 <li><em>Section 3.3.1</em> <a href="#rfc.xref.RFC4647.4">1 1.14</a></li>5137 <li><em>RFC4288</em> <a href="#rfc.xref.RFC4288.1">6.5</a>, <a href="#RFC4288"><b>14.1</b></a></li> 5138 <li><em>RFC4647</em> <a href="#rfc.xref.RFC4647.1">10.14</a>, <a href="#rfc.xref.RFC4647.2">10.14</a>, <a href="#rfc.xref.RFC4647.3">10.14</a>, <a href="#rfc.xref.RFC4647.4">10.14</a>, <a href="#RFC4647"><b>14.1</b></a><ul> 5139 <li><em>Section 2.1</em> <a href="#rfc.xref.RFC4647.1">10.14</a></li> 5140 <li><em>Section 2.3</em> <a href="#rfc.xref.RFC4647.2">10.14</a></li> 5141 <li><em>Section 3</em> <a href="#rfc.xref.RFC4647.3">10.14</a></li> 5142 <li><em>Section 3.3.1</em> <a href="#rfc.xref.RFC4647.4">10.14</a></li> 5148 5143 </ul> 5149 5144 </li> 5150 <li><em>RFC5226</em> <a href="#rfc.xref.RFC5226.1">2.2</a>, <a href="#rfc.xref.RFC5226.2">4.2</a>, <a href="#rfc.xref.RFC5226.3"> 7.2.1</a>, <a href="#RFC5226"><b>15.2</b></a><ul>5151 <li><em>Section 4.1</em> <a href="#rfc.xref.RFC5226.1">2.2</a>, <a href="#rfc.xref.RFC5226.2">4.2</a>, <a href="#rfc.xref.RFC5226.3"> 7.2.1</a></li>5145 <li><em>RFC5226</em> <a href="#rfc.xref.RFC5226.1">2.2</a>, <a href="#rfc.xref.RFC5226.2">4.2</a>, <a href="#rfc.xref.RFC5226.3">6.4.1</a>, <a href="#RFC5226"><b>14.2</b></a><ul> 5146 <li><em>Section 4.1</em> <a href="#rfc.xref.RFC5226.1">2.2</a>, <a href="#rfc.xref.RFC5226.2">4.2</a>, <a href="#rfc.xref.RFC5226.3">6.4.1</a></li> 5152 5147 </ul> 5153 5148 </li> 5154 <li><em>RFC5234</em> <a href="#rfc.xref.RFC5234.1">1.3</a>, <a href="#rfc.xref.RFC5234.2">1.3</a>, <a href="#rfc.xref.RFC5234.3">3.1</a>, <a href="#RFC5234"><b>1 5.1</b></a><ul>5149 <li><em>RFC5234</em> <a href="#rfc.xref.RFC5234.1">1.3</a>, <a href="#rfc.xref.RFC5234.2">1.3</a>, <a href="#rfc.xref.RFC5234.3">3.1</a>, <a href="#RFC5234"><b>14.1</b></a><ul> 5155 5150 <li><em>Appendix B.1</em> <a href="#rfc.xref.RFC5234.2">1.3</a></li> 5156 5151 </ul> 5157 5152 </li> 5158 <li><em>RFC5322</em> <a href="#rfc.xref.RFC5322.1">6.1</a>, <a href="#rfc.xref.RFC5322.2">1 1.2</a>, <a href="#rfc.xref.RFC5322.3">11.4</a>, <a href="#rfc.xref.RFC5322.4">11.4</a>, <a href="#RFC5322"><b>15.2</b></a>, <a href="#rfc.xref.RFC5322.5">A</a><ul>5153 <li><em>RFC5322</em> <a href="#rfc.xref.RFC5322.1">6.1</a>, <a href="#rfc.xref.RFC5322.2">10.2</a>, <a href="#rfc.xref.RFC5322.3">10.4</a>, <a href="#rfc.xref.RFC5322.4">10.4</a>, <a href="#RFC5322"><b>14.2</b></a>, <a href="#rfc.xref.RFC5322.5">A</a><ul> 5159 5154 <li><em>Section 3.3</em> <a href="#rfc.xref.RFC5322.1">6.1</a></li> 5160 <li><em>Section 3.4</em> <a href="#rfc.xref.RFC5322.3">1 1.4</a>, <a href="#rfc.xref.RFC5322.4">11.4</a></li>5161 <li><em>Section 3.6.1</em> <a href="#rfc.xref.RFC5322.2">1 1.2</a></li>5155 <li><em>Section 3.4</em> <a href="#rfc.xref.RFC5322.3">10.4</a>, <a href="#rfc.xref.RFC5322.4">10.4</a></li> 5156 <li><em>Section 3.6.1</em> <a href="#rfc.xref.RFC5322.2">10.2</a></li> 5162 5157 </ul> 5163 5158 </li> 5164 <li><em>RFC5646</em> <a href="#rfc.xref.RFC5646.1"> 7.4</a>, <a href="#rfc.xref.RFC5646.2">7.4</a>, <a href="#rfc.xref.RFC5646.3">7.4</a>, <a href="#RFC5646"><b>15.1</b></a><ul>5165 <li><em>Section 2.1</em> <a href="#rfc.xref.RFC5646.2"> 7.4</a></li>5159 <li><em>RFC5646</em> <a href="#rfc.xref.RFC5646.1">6.6</a>, <a href="#rfc.xref.RFC5646.2">6.6</a>, <a href="#rfc.xref.RFC5646.3">6.6</a>, <a href="#RFC5646"><b>14.1</b></a><ul> 5160 <li><em>Section 2.1</em> <a href="#rfc.xref.RFC5646.2">6.6</a></li> 5166 5161 </ul> 5167 5162 </li> 5168 <li><em>RFC5789</em> <a href="#rfc.xref.RFC5789.1">2.3.5</a>, <a href="#RFC5789"><b>1 5.2</b></a></li>5169 <li><em>RFC5987</em> <a href="#rfc.xref.RFC5987.1">3.1</a>, <a href="#RFC5987"><b>1 5.2</b></a></li>5170 <li><em>RFC6151</em> <a href="#RFC6151"><b>1 5.2</b></a>, <a href="#rfc.xref.RFC6151.1">C</a></li>5171 <li><em>RFC6266</em> <a href="#RFC6266"><b>1 5.2</b></a>, <a href="#rfc.xref.RFC6266.1">B</a>, <a href="#rfc.xref.RFC6266.2">C</a></li>5163 <li><em>RFC5789</em> <a href="#rfc.xref.RFC5789.1">2.3.5</a>, <a href="#RFC5789"><b>14.2</b></a></li> 5164 <li><em>RFC5987</em> <a href="#rfc.xref.RFC5987.1">3.1</a>, <a href="#RFC5987"><b>14.2</b></a></li> 5165 <li><em>RFC6151</em> <a href="#RFC6151"><b>14.2</b></a>, <a href="#rfc.xref.RFC6151.1">C</a></li> 5166 <li><em>RFC6266</em> <a href="#RFC6266"><b>14.2</b></a>, <a href="#rfc.xref.RFC6266.1">B</a>, <a href="#rfc.xref.RFC6266.2">C</a></li> 5172 5167 </ul> 5173 5168 </li> … … 5175 5170 <li>Safe Methods <a href="#rfc.iref.s.2"><b>2.1.1</b></a></li> 5176 5171 <li>selected representation <a href="#rfc.iref.s.1"><b>1.1</b></a></li> 5177 <li>Server header field <a href="#rfc.xref.header.server.1">3.3</a>, <a href="#rfc.iref.s.39"><b>1 1.9</b></a>, <a href="#rfc.xref.header.server.2">12.3</a>, <a href="#rfc.xref.header.server.3">13.1</a>, <a href="#rfc.xref.header.server.4">C</a></li>5172 <li>Server header field <a href="#rfc.xref.header.server.1">3.3</a>, <a href="#rfc.iref.s.39"><b>10.9</b></a>, <a href="#rfc.xref.header.server.2">11.3</a>, <a href="#rfc.xref.header.server.3">12.1</a>, <a href="#rfc.xref.header.server.4">C</a></li> 5178 5173 <li>Status Codes 5179 5174 <ul> 5180 <li>100 Continue <a href="#rfc.xref.status.100.1">4.1</a>, <a href="#rfc.iref.s.3"><b>4.3.1</b></a>, <a href="#rfc.xref.status.100.2">1 2.2</a></li>5181 <li>101 Switching Protocols <a href="#rfc.xref.status.101.1">4.1</a>, <a href="#rfc.iref.s.4"><b>4.3.2</b></a>, <a href="#rfc.xref.status.101.2">1 2.2</a></li>5182 <li>200 OK <a href="#rfc.xref.status.200.1">4.1</a>, <a href="#rfc.iref.s.5"><b>4.4.1</b></a>, <a href="#rfc.xref.status.200.2">1 2.2</a></li>5183 <li>201 Created <a href="#rfc.xref.status.201.1">4.1</a>, <a href="#rfc.iref.s.6"><b>4.4.2</b></a>, <a href="#rfc.xref.status.201.2">1 2.2</a></li>5184 <li>202 Accepted <a href="#rfc.xref.status.202.1">4.1</a>, <a href="#rfc.iref.s.7"><b>4.4.3</b></a>, <a href="#rfc.xref.status.202.2">1 2.2</a></li>5185 <li>203 Non-Authoritative Information <a href="#rfc.xref.status.203.1">4.1</a>, <a href="#rfc.iref.s.8"><b>4.4.4</b></a>, <a href="#rfc.xref.status.203.2">1 2.2</a>, <a href="#rfc.xref.status.203.3">C</a></li>5186 <li>204 No Content <a href="#rfc.xref.status.204.1">4.1</a>, <a href="#rfc.iref.s.9"><b>4.4.5</b></a>, <a href="#rfc.xref.status.204.2">1 2.2</a></li>5187 <li>205 Reset Content <a href="#rfc.xref.status.205.1">4.1</a>, <a href="#rfc.iref.s.10"><b>4.4.6</b></a>, <a href="#rfc.xref.status.205.2">1 2.2</a></li>5188 <li>300 Multiple Choices <a href="#rfc.xref.status.300.1">4.1</a>, <a href="#rfc.iref.s.11"><b>4.5.1</b></a>, <a href="#rfc.xref.status.300.2">1 2.2</a></li>5189 <li>301 Moved Permanently <a href="#rfc.xref.status.301.1">4.1</a>, <a href="#rfc.iref.s.12"><b>4.5.2</b></a>, <a href="#rfc.xref.status.301.2">1 2.2</a>, <a href="#rfc.xref.status.301.3">C</a></li>5190 <li>302 Found <a href="#rfc.xref.status.302.1">4.1</a>, <a href="#rfc.iref.s.13"><b>4.5.3</b></a>, <a href="#rfc.xref.status.302.2">1 2.2</a>, <a href="#rfc.xref.status.302.3">C</a></li>5191 <li>303 See Other <a href="#rfc.xref.status.303.1">4.1</a>, <a href="#rfc.iref.s.14"><b>4.5.4</b></a>, <a href="#rfc.xref.status.303.2">1 2.2</a></li>5192 <li>305 Use Proxy <a href="#rfc.xref.status.305.1">4.1</a>, <a href="#rfc.iref.s.15"><b>4.5.5</b></a>, <a href="#rfc.xref.status.305.2">1 2.2</a>, <a href="#rfc.xref.status.305.3">C</a></li>5193 <li>306 (Unused) <a href="#rfc.iref.s.16"><b>4.5.6</b></a>, <a href="#rfc.xref.status.306.1">1 2.2</a></li>5194 <li>307 Temporary Redirect <a href="#rfc.xref.status.307.1">4.1</a>, <a href="#rfc.iref.s.17"><b>4.5.7</b></a>, <a href="#rfc.xref.status.307.2">1 2.2</a>, <a href="#rfc.xref.status.307.3">C</a></li>5195 <li>400 Bad Request <a href="#rfc.xref.status.400.1">4.1</a>, <a href="#rfc.iref.s.18"><b>4.6.1</b></a>, <a href="#rfc.xref.status.400.2">1 2.2</a></li>5196 <li>402 Payment Required <a href="#rfc.xref.status.402.1">4.1</a>, <a href="#rfc.iref.s.19"><b>4.6.2</b></a>, <a href="#rfc.xref.status.402.2">1 2.2</a></li>5197 <li>403 Forbidden <a href="#rfc.xref.status.403.1">4.1</a>, <a href="#rfc.iref.s.20"><b>4.6.3</b></a>, <a href="#rfc.xref.status.403.2">1 2.2</a></li>5198 <li>404 Not Found <a href="#rfc.xref.status.404.1">4.1</a>, <a href="#rfc.iref.s.21"><b>4.6.4</b></a>, <a href="#rfc.xref.status.404.2">1 2.2</a></li>5199 <li>405 Method Not Allowed <a href="#rfc.xref.status.405.1">4.1</a>, <a href="#rfc.iref.s.22"><b>4.6.5</b></a>, <a href="#rfc.xref.status.405.2">1 2.2</a></li>5200 <li>406 Not Acceptable <a href="#rfc.xref.status.406.1">4.1</a>, <a href="#rfc.iref.s.23"><b>4.6.6</b></a>, <a href="#rfc.xref.status.406.2">1 2.2</a></li>5201 <li>408 Request Timeout <a href="#rfc.xref.status.408.1">4.1</a>, <a href="#rfc.iref.s.24"><b>4.6.7</b></a>, <a href="#rfc.xref.status.408.2">1 2.2</a></li>5202 <li>409 Conflict <a href="#rfc.xref.status.409.1">4.1</a>, <a href="#rfc.iref.s.25"><b>4.6.8</b></a>, <a href="#rfc.xref.status.409.2">1 2.2</a></li>5203 <li>410 Gone <a href="#rfc.xref.status.410.1">4.1</a>, <a href="#rfc.iref.s.26"><b>4.6.9</b></a>, <a href="#rfc.xref.status.410.2">1 2.2</a></li>5204 <li>411 Length Required <a href="#rfc.xref.status.411.1">4.1</a>, <a href="#rfc.iref.s.27"><b>4.6.10</b></a>, <a href="#rfc.xref.status.411.2">1 2.2</a></li>5205 <li>413 Request Representation Too Large <a href="#rfc.xref.status.413.1">4.1</a>, <a href="#rfc.iref.s.28"><b>4.6.11</b></a>, <a href="#rfc.xref.status.413.2">1 2.2</a></li>5206 <li>414 URI Too Long <a href="#rfc.xref.status.414.1">4.1</a>, <a href="#rfc.iref.s.29"><b>4.6.12</b></a>, <a href="#rfc.xref.status.414.2">1 2.2</a></li>5207 <li>415 Unsupported Media Type <a href="#rfc.xref.status.415.1">4.1</a>, <a href="#rfc.iref.s.30"><b>4.6.13</b></a>, <a href="#rfc.xref.status.415.2">1 2.2</a></li>5208 <li>417 Expectation Failed <a href="#rfc.xref.status.417.1">4.1</a>, <a href="#rfc.iref.s.31"><b>4.6.14</b></a>, <a href="#rfc.xref.status.417.2">1 2.2</a></li>5209 <li>426 Upgrade Required <a href="#rfc.xref.status.426.1">4.1</a>, <a href="#rfc.iref.s.32"><b>4.6.15</b></a>, <a href="#rfc.xref.status.426.2">1 2.2</a>, <a href="#rfc.xref.status.426.3">C</a></li>5210 <li>500 Internal Server Error <a href="#rfc.xref.status.500.1">4.1</a>, <a href="#rfc.iref.s.33"><b>4.7.1</b></a>, <a href="#rfc.xref.status.500.2">1 2.2</a></li>5211 <li>501 Not Implemented <a href="#rfc.xref.status.501.1">4.1</a>, <a href="#rfc.iref.s.34"><b>4.7.2</b></a>, <a href="#rfc.xref.status.501.2">1 2.2</a></li>5212 <li>502 Bad Gateway <a href="#rfc.xref.status.502.1">4.1</a>, <a href="#rfc.iref.s.35"><b>4.7.3</b></a>, <a href="#rfc.xref.status.502.2">1 2.2</a></li>5213 <li>503 Service Unavailable <a href="#rfc.xref.status.503.1">4.1</a>, <a href="#rfc.iref.s.36"><b>4.7.4</b></a>, <a href="#rfc.xref.status.503.2">1 2.2</a></li>5214 <li>504 Gateway Timeout <a href="#rfc.xref.status.504.1">4.1</a>, <a href="#rfc.iref.s.37"><b>4.7.5</b></a>, <a href="#rfc.xref.status.504.2">1 2.2</a></li>5215 <li>505 HTTP Version Not Supported <a href="#rfc.xref.status.505.1">4.1</a>, <a href="#rfc.iref.s.38"><b>4.7.6</b></a>, <a href="#rfc.xref.status.505.2">1 2.2</a></li>5175 <li>100 Continue <a href="#rfc.xref.status.100.1">4.1</a>, <a href="#rfc.iref.s.3"><b>4.3.1</b></a>, <a href="#rfc.xref.status.100.2">11.2</a></li> 5176 <li>101 Switching Protocols <a href="#rfc.xref.status.101.1">4.1</a>, <a href="#rfc.iref.s.4"><b>4.3.2</b></a>, <a href="#rfc.xref.status.101.2">11.2</a></li> 5177 <li>200 OK <a href="#rfc.xref.status.200.1">4.1</a>, <a href="#rfc.iref.s.5"><b>4.4.1</b></a>, <a href="#rfc.xref.status.200.2">11.2</a></li> 5178 <li>201 Created <a href="#rfc.xref.status.201.1">4.1</a>, <a href="#rfc.iref.s.6"><b>4.4.2</b></a>, <a href="#rfc.xref.status.201.2">11.2</a></li> 5179 <li>202 Accepted <a href="#rfc.xref.status.202.1">4.1</a>, <a href="#rfc.iref.s.7"><b>4.4.3</b></a>, <a href="#rfc.xref.status.202.2">11.2</a></li> 5180 <li>203 Non-Authoritative Information <a href="#rfc.xref.status.203.1">4.1</a>, <a href="#rfc.iref.s.8"><b>4.4.4</b></a>, <a href="#rfc.xref.status.203.2">11.2</a>, <a href="#rfc.xref.status.203.3">C</a></li> 5181 <li>204 No Content <a href="#rfc.xref.status.204.1">4.1</a>, <a href="#rfc.iref.s.9"><b>4.4.5</b></a>, <a href="#rfc.xref.status.204.2">11.2</a></li> 5182 <li>205 Reset Content <a href="#rfc.xref.status.205.1">4.1</a>, <a href="#rfc.iref.s.10"><b>4.4.6</b></a>, <a href="#rfc.xref.status.205.2">11.2</a></li> 5183 <li>300 Multiple Choices <a href="#rfc.xref.status.300.1">4.1</a>, <a href="#rfc.iref.s.11"><b>4.5.1</b></a>, <a href="#rfc.xref.status.300.2">11.2</a></li> 5184 <li>301 Moved Permanently <a href="#rfc.xref.status.301.1">4.1</a>, <a href="#rfc.iref.s.12"><b>4.5.2</b></a>, <a href="#rfc.xref.status.301.2">11.2</a>, <a href="#rfc.xref.status.301.3">C</a></li> 5185 <li>302 Found <a href="#rfc.xref.status.302.1">4.1</a>, <a href="#rfc.iref.s.13"><b>4.5.3</b></a>, <a href="#rfc.xref.status.302.2">11.2</a>, <a href="#rfc.xref.status.302.3">C</a></li> 5186 <li>303 See Other <a href="#rfc.xref.status.303.1">4.1</a>, <a href="#rfc.iref.s.14"><b>4.5.4</b></a>, <a href="#rfc.xref.status.303.2">11.2</a></li> 5187 <li>305 Use Proxy <a href="#rfc.xref.status.305.1">4.1</a>, <a href="#rfc.iref.s.15"><b>4.5.5</b></a>, <a href="#rfc.xref.status.305.2">11.2</a>, <a href="#rfc.xref.status.305.3">C</a></li> 5188 <li>306 (Unused) <a href="#rfc.iref.s.16"><b>4.5.6</b></a>, <a href="#rfc.xref.status.306.1">11.2</a></li> 5189 <li>307 Temporary Redirect <a href="#rfc.xref.status.307.1">4.1</a>, <a href="#rfc.iref.s.17"><b>4.5.7</b></a>, <a href="#rfc.xref.status.307.2">11.2</a>, <a href="#rfc.xref.status.307.3">C</a></li> 5190 <li>400 Bad Request <a href="#rfc.xref.status.400.1">4.1</a>, <a href="#rfc.iref.s.18"><b>4.6.1</b></a>, <a href="#rfc.xref.status.400.2">11.2</a></li> 5191 <li>402 Payment Required <a href="#rfc.xref.status.402.1">4.1</a>, <a href="#rfc.iref.s.19"><b>4.6.2</b></a>, <a href="#rfc.xref.status.402.2">11.2</a></li> 5192 <li>403 Forbidden <a href="#rfc.xref.status.403.1">4.1</a>, <a href="#rfc.iref.s.20"><b>4.6.3</b></a>, <a href="#rfc.xref.status.403.2">11.2</a></li> 5193 <li>404 Not Found <a href="#rfc.xref.status.404.1">4.1</a>, <a href="#rfc.iref.s.21"><b>4.6.4</b></a>, <a href="#rfc.xref.status.404.2">11.2</a></li> 5194 <li>405 Method Not Allowed <a href="#rfc.xref.status.405.1">4.1</a>, <a href="#rfc.iref.s.22"><b>4.6.5</b></a>, <a href="#rfc.xref.status.405.2">11.2</a></li> 5195 <li>406 Not Acceptable <a href="#rfc.xref.status.406.1">4.1</a>, <a href="#rfc.iref.s.23"><b>4.6.6</b></a>, <a href="#rfc.xref.status.406.2">11.2</a></li> 5196 <li>408 Request Timeout <a href="#rfc.xref.status.408.1">4.1</a>, <a href="#rfc.iref.s.24"><b>4.6.7</b></a>, <a href="#rfc.xref.status.408.2">11.2</a></li> 5197 <li>409 Conflict <a href="#rfc.xref.status.409.1">4.1</a>, <a href="#rfc.iref.s.25"><b>4.6.8</b></a>, <a href="#rfc.xref.status.409.2">11.2</a></li> 5198 <li>410 Gone <a href="#rfc.xref.status.410.1">4.1</a>, <a href="#rfc.iref.s.26"><b>4.6.9</b></a>, <a href="#rfc.xref.status.410.2">11.2</a></li> 5199 <li>411 Length Required <a href="#rfc.xref.status.411.1">4.1</a>, <a href="#rfc.iref.s.27"><b>4.6.10</b></a>, <a href="#rfc.xref.status.411.2">11.2</a></li> 5200 <li>413 Request Representation Too Large <a href="#rfc.xref.status.413.1">4.1</a>, <a href="#rfc.iref.s.28"><b>4.6.11</b></a>, <a href="#rfc.xref.status.413.2">11.2</a></li> 5201 <li>414 URI Too Long <a href="#rfc.xref.status.414.1">4.1</a>, <a href="#rfc.iref.s.29"><b>4.6.12</b></a>, <a href="#rfc.xref.status.414.2">11.2</a></li> 5202 <li>415 Unsupported Media Type <a href="#rfc.xref.status.415.1">4.1</a>, <a href="#rfc.iref.s.30"><b>4.6.13</b></a>, <a href="#rfc.xref.status.415.2">11.2</a></li> 5203 <li>417 Expectation Failed <a href="#rfc.xref.status.417.1">4.1</a>, <a href="#rfc.iref.s.31"><b>4.6.14</b></a>, <a href="#rfc.xref.status.417.2">11.2</a></li> 5204 <li>426 Upgrade Required <a href="#rfc.xref.status.426.1">4.1</a>, <a href="#rfc.iref.s.32"><b>4.6.15</b></a>, <a href="#rfc.xref.status.426.2">11.2</a>, <a href="#rfc.xref.status.426.3">C</a></li> 5205 <li>500 Internal Server Error <a href="#rfc.xref.status.500.1">4.1</a>, <a href="#rfc.iref.s.33"><b>4.7.1</b></a>, <a href="#rfc.xref.status.500.2">11.2</a></li> 5206 <li>501 Not Implemented <a href="#rfc.xref.status.501.1">4.1</a>, <a href="#rfc.iref.s.34"><b>4.7.2</b></a>, <a href="#rfc.xref.status.501.2">11.2</a></li> 5207 <li>502 Bad Gateway <a href="#rfc.xref.status.502.1">4.1</a>, <a href="#rfc.iref.s.35"><b>4.7.3</b></a>, <a href="#rfc.xref.status.502.2">11.2</a></li> 5208 <li>503 Service Unavailable <a href="#rfc.xref.status.503.1">4.1</a>, <a href="#rfc.iref.s.36"><b>4.7.4</b></a>, <a href="#rfc.xref.status.503.2">11.2</a></li> 5209 <li>504 Gateway Timeout <a href="#rfc.xref.status.504.1">4.1</a>, <a href="#rfc.iref.s.37"><b>4.7.5</b></a>, <a href="#rfc.xref.status.504.2">11.2</a></li> 5210 <li>505 HTTP Version Not Supported <a href="#rfc.xref.status.505.1">4.1</a>, <a href="#rfc.iref.s.38"><b>4.7.6</b></a>, <a href="#rfc.xref.status.505.2">11.2</a></li> 5216 5211 </ul> 5217 5212 </li> … … 5219 5214 </li> 5220 5215 <li><a id="rfc.index.T" href="#rfc.index.T"><b>T</b></a><ul> 5221 <li>TRACE method <a href="#rfc.iref.t.1"><b>2.3.7</b></a>, <a href="#rfc.xref.TRACE.1">1 1.6</a>, <a href="#rfc.xref.TRACE.2">12.1</a>, <a href="#rfc.xref.TRACE.3">13.1</a></li>5216 <li>TRACE method <a href="#rfc.iref.t.1"><b>2.3.7</b></a>, <a href="#rfc.xref.TRACE.1">10.6</a>, <a href="#rfc.xref.TRACE.2">11.1</a>, <a href="#rfc.xref.TRACE.3">12.1</a></li> 5222 5217 </ul> 5223 5218 </li> 5224 5219 <li><a id="rfc.index.U" href="#rfc.index.U"><b>U</b></a><ul> 5225 <li>User-Agent header field <a href="#rfc.xref.header.user-agent.1">3.2</a>, <a href="#rfc.xref.header.user-agent.2"> 10.1</a>, <a href="#rfc.iref.u.1"><b>11.10</b></a>, <a href="#rfc.xref.header.user-agent.3">12.3</a>, <a href="#rfc.xref.header.user-agent.4">13.1</a></li>5220 <li>User-Agent header field <a href="#rfc.xref.header.user-agent.1">3.2</a>, <a href="#rfc.xref.header.user-agent.2">9.1</a>, <a href="#rfc.iref.u.1"><b>10.10</b></a>, <a href="#rfc.xref.header.user-agent.3">11.3</a>, <a href="#rfc.xref.header.user-agent.4">12.1</a></li> 5226 5221 </ul> 5227 5222 </li> -
draft-ietf-httpbis/experiment/p2-semantics.xml
r1627 r1629 2325 2325 </t> 2326 2326 </section> 2327 </section>2328 2329 <section title="Protocol Parameters" anchor="protocol.parameters">2330 2327 2331 2328 <section title="Character Encodings (charset)" anchor="character.sets">
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