Changeset 1851
- Timestamp:
- 02/09/12 06:46:39 (10 years ago)
- Location:
- draft-ietf-httpbis/latest
- Files:
-
- 2 edited
Legend:
- Unmodified
- Added
- Removed
-
draft-ietf-httpbis/latest/p2-semantics.html
r1850 r1851 475 475 <link rel="Chapter" title="3 Representation" href="#rfc.section.3"> 476 476 <link rel="Chapter" title="4 Request Methods" href="#rfc.section.4"> 477 <link rel="Chapter" title="5 Header Fields" href="#rfc.section.5">477 <link rel="Chapter" title="5 Request Header Fields" href="#rfc.section.5"> 478 478 <link rel="Chapter" title="6 Response Status Codes" href="#rfc.section.6"> 479 <link rel="Chapter" title="7 Protocol Parameters" href="#rfc.section.7"> 480 <link rel="Chapter" title="8 Payload" href="#rfc.section.8"> 481 <link rel="Chapter" title="9 Content Negotiation" href="#rfc.section.9"> 482 <link rel="Chapter" title="10 Header Field Definitions" href="#rfc.section.10"> 483 <link rel="Chapter" title="11 IANA Considerations" href="#rfc.section.11"> 484 <link rel="Chapter" title="12 Security Considerations" href="#rfc.section.12"> 485 <link rel="Chapter" title="13 Acknowledgments" href="#rfc.section.13"> 486 <link rel="Chapter" href="#rfc.section.14" title="14 References"> 479 <link rel="Chapter" title="7 Response Header Fields" href="#rfc.section.7"> 480 <link rel="Chapter" title="8 Protocol Parameters" href="#rfc.section.8"> 481 <link rel="Chapter" title="9 Payload" href="#rfc.section.9"> 482 <link rel="Chapter" title="10 Content Negotiation" href="#rfc.section.10"> 483 <link rel="Chapter" title="11 Header Field Definitions" href="#rfc.section.11"> 484 <link rel="Chapter" title="12 IANA Considerations" href="#rfc.section.12"> 485 <link rel="Chapter" title="13 Security Considerations" href="#rfc.section.13"> 486 <link rel="Chapter" title="14 Acknowledgments" href="#rfc.section.14"> 487 <link rel="Chapter" href="#rfc.section.15" title="15 References"> 487 488 <link rel="Appendix" title="A Differences between HTTP and MIME" href="#rfc.section.A"> 488 489 <link rel="Appendix" title="B Additional Features" href="#rfc.section.B"> … … 613 614 </ul> 614 615 </li> 615 <li><a href="#rfc.section.5">5.</a> <a href="#header.fields">Header Fields</a><ul> 616 <li><a href="#rfc.section.5.1">5.1</a> <a href="#request.fields">Request-modifier Header Fields</a></li> 617 <li><a href="#rfc.section.5.2">5.2</a> <a href="#response.fields">Status-modifier Header Fields</a></li> 618 <li><a href="#rfc.section.5.3">5.3</a> <a href="#resource.fields">Resource Metadata Fields</a></li> 619 <li><a href="#rfc.section.5.4">5.4</a> <a href="#payload.fields">Payload Metadata Fields</a></li> 620 <li><a href="#rfc.section.5.5">5.5</a> <a href="#request.header.fields">Request Header Fields</a></li> 621 <li><a href="#rfc.section.5.6">5.6</a> <a href="#response.header.fields">Response Header Fields</a></li> 616 <li><a href="#rfc.section.5">5.</a> <a href="#request.header.fields">Request Header Fields</a><ul> 617 <li><a href="#rfc.section.5.1">5.1</a> <a href="#request.controls">Controls</a></li> 618 <li><a href="#rfc.section.5.2">5.2</a> <a href="#request.conditionals">Conditionals</a></li> 619 <li><a href="#rfc.section.5.3">5.3</a> <a href="#request.conneg">Content Negotiation</a></li> 620 <li><a href="#rfc.section.5.4">5.4</a> <a href="#request.inform">Information</a></li> 622 621 </ul> 623 622 </li> … … 677 676 </ul> 678 677 </li> 679 <li><a href="#rfc.section.7">7.</a> <a href="#protocol.parameters">Protocol Parameters</a><ul> 680 <li><a href="#rfc.section.7.1">7.1</a> <a href="#http.date">Date/Time Formats</a></li> 681 <li><a href="#rfc.section.7.2">7.2</a> <a href="#product.tokens">Product Tokens</a></li> 682 <li><a href="#rfc.section.7.3">7.3</a> <a href="#character.sets">Character Encodings (charset)</a></li> 683 <li><a href="#rfc.section.7.4">7.4</a> <a href="#content.codings">Content Codings</a></li> 684 <li><a href="#rfc.section.7.5">7.5</a> <a href="#media.types">Media Types</a><ul> 685 <li><a href="#rfc.section.7.5.1">7.5.1</a> <a href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></li> 686 <li><a href="#rfc.section.7.5.2">7.5.2</a> <a href="#multipart.types">Multipart Types</a></li> 678 <li><a href="#rfc.section.7">7.</a> <a href="#response.header.fields">Response Header Fields</a></li> 679 <li><a href="#rfc.section.8">8.</a> <a href="#protocol.parameters">Protocol Parameters</a><ul> 680 <li><a href="#rfc.section.8.1">8.1</a> <a href="#http.date">Date/Time Formats</a></li> 681 <li><a href="#rfc.section.8.2">8.2</a> <a href="#product.tokens">Product Tokens</a></li> 682 <li><a href="#rfc.section.8.3">8.3</a> <a href="#character.sets">Character Encodings (charset)</a></li> 683 <li><a href="#rfc.section.8.4">8.4</a> <a href="#content.codings">Content Codings</a></li> 684 <li><a href="#rfc.section.8.5">8.5</a> <a href="#media.types">Media Types</a><ul> 685 <li><a href="#rfc.section.8.5.1">8.5.1</a> <a href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></li> 686 <li><a href="#rfc.section.8.5.2">8.5.2</a> <a href="#multipart.types">Multipart Types</a></li> 687 687 </ul> 688 688 </li> 689 <li><a href="#rfc.section. 7.6">7.6</a> <a href="#language.tags">Language Tags</a></li>689 <li><a href="#rfc.section.8.6">8.6</a> <a href="#language.tags">Language Tags</a></li> 690 690 </ul> 691 691 </li> 692 <li><a href="#rfc.section. 8">8.</a> <a href="#payload">Payload</a><ul>693 <li><a href="#rfc.section. 8.1">8.1</a> <a href="#payload.header.fields">Payload Header Fields</a></li>694 <li><a href="#rfc.section. 8.2">8.2</a> <a href="#payload.body">Payload Body</a></li>692 <li><a href="#rfc.section.9">9.</a> <a href="#payload">Payload</a><ul> 693 <li><a href="#rfc.section.9.1">9.1</a> <a href="#payload.header.fields">Payload Header Fields</a></li> 694 <li><a href="#rfc.section.9.2">9.2</a> <a href="#payload.body">Payload Body</a></li> 695 695 </ul> 696 696 </li> 697 <li><a href="#rfc.section. 9">9.</a> <a href="#content.negotiation">Content Negotiation</a><ul>698 <li><a href="#rfc.section. 9.1">9.1</a> <a href="#server-driven.negotiation">Server-driven Negotiation</a></li>699 <li><a href="#rfc.section. 9.2">9.2</a> <a href="#agent-driven.negotiation">Agent-driven Negotiation</a></li>700 <li><a href="#rfc.section. 9.3">9.3</a> <a href="#quality.values">Quality Values</a></li>697 <li><a href="#rfc.section.10">10.</a> <a href="#content.negotiation">Content Negotiation</a><ul> 698 <li><a href="#rfc.section.10.1">10.1</a> <a href="#server-driven.negotiation">Server-driven Negotiation</a></li> 699 <li><a href="#rfc.section.10.2">10.2</a> <a href="#agent-driven.negotiation">Agent-driven Negotiation</a></li> 700 <li><a href="#rfc.section.10.3">10.3</a> <a href="#quality.values">Quality Values</a></li> 701 701 </ul> 702 702 </li> 703 <li><a href="#rfc.section.1 0">10.</a> <a href="#header.field.definitions">Header Field Definitions</a><ul>704 <li><a href="#rfc.section.1 0.1">10.1</a> <a href="#header.accept">Accept</a></li>705 <li><a href="#rfc.section.1 0.2">10.2</a> <a href="#header.accept-charset">Accept-Charset</a></li>706 <li><a href="#rfc.section.1 0.3">10.3</a> <a href="#header.accept-encoding">Accept-Encoding</a></li>707 <li><a href="#rfc.section.1 0.4">10.4</a> <a href="#header.accept-language">Accept-Language</a></li>708 <li><a href="#rfc.section.1 0.5">10.5</a> <a href="#header.allow">Allow</a></li>709 <li><a href="#rfc.section.1 0.6">10.6</a> <a href="#header.content-encoding">Content-Encoding</a></li>710 <li><a href="#rfc.section.1 0.7">10.7</a> <a href="#header.content-language">Content-Language</a></li>711 <li><a href="#rfc.section.1 0.8">10.8</a> <a href="#header.content-location">Content-Location</a></li>712 <li><a href="#rfc.section.1 0.9">10.9</a> <a href="#header.content-type">Content-Type</a></li>713 <li><a href="#rfc.section.1 0.10">10.10</a> <a href="#header.date">Date</a></li>714 <li><a href="#rfc.section.1 0.11">10.11</a> <a href="#header.expect">Expect</a></li>715 <li><a href="#rfc.section.1 0.12">10.12</a> <a href="#header.from">From</a></li>716 <li><a href="#rfc.section.1 0.13">10.13</a> <a href="#header.location">Location</a></li>717 <li><a href="#rfc.section.1 0.14">10.14</a> <a href="#header.max-forwards">Max-Forwards</a></li>718 <li><a href="#rfc.section.1 0.15">10.15</a> <a href="#header.referer">Referer</a></li>719 <li><a href="#rfc.section.1 0.16">10.16</a> <a href="#header.retry-after">Retry-After</a></li>720 <li><a href="#rfc.section.1 0.17">10.17</a> <a href="#header.server">Server</a></li>721 <li><a href="#rfc.section.1 0.18">10.18</a> <a href="#header.user-agent">User-Agent</a></li>703 <li><a href="#rfc.section.11">11.</a> <a href="#header.field.definitions">Header Field Definitions</a><ul> 704 <li><a href="#rfc.section.11.1">11.1</a> <a href="#header.accept">Accept</a></li> 705 <li><a href="#rfc.section.11.2">11.2</a> <a href="#header.accept-charset">Accept-Charset</a></li> 706 <li><a href="#rfc.section.11.3">11.3</a> <a href="#header.accept-encoding">Accept-Encoding</a></li> 707 <li><a href="#rfc.section.11.4">11.4</a> <a href="#header.accept-language">Accept-Language</a></li> 708 <li><a href="#rfc.section.11.5">11.5</a> <a href="#header.allow">Allow</a></li> 709 <li><a href="#rfc.section.11.6">11.6</a> <a href="#header.content-encoding">Content-Encoding</a></li> 710 <li><a href="#rfc.section.11.7">11.7</a> <a href="#header.content-language">Content-Language</a></li> 711 <li><a href="#rfc.section.11.8">11.8</a> <a href="#header.content-location">Content-Location</a></li> 712 <li><a href="#rfc.section.11.9">11.9</a> <a href="#header.content-type">Content-Type</a></li> 713 <li><a href="#rfc.section.11.10">11.10</a> <a href="#header.date">Date</a></li> 714 <li><a href="#rfc.section.11.11">11.11</a> <a href="#header.expect">Expect</a></li> 715 <li><a href="#rfc.section.11.12">11.12</a> <a href="#header.from">From</a></li> 716 <li><a href="#rfc.section.11.13">11.13</a> <a href="#header.location">Location</a></li> 717 <li><a href="#rfc.section.11.14">11.14</a> <a href="#header.max-forwards">Max-Forwards</a></li> 718 <li><a href="#rfc.section.11.15">11.15</a> <a href="#header.referer">Referer</a></li> 719 <li><a href="#rfc.section.11.16">11.16</a> <a href="#header.retry-after">Retry-After</a></li> 720 <li><a href="#rfc.section.11.17">11.17</a> <a href="#header.server">Server</a></li> 721 <li><a href="#rfc.section.11.18">11.18</a> <a href="#header.user-agent">User-Agent</a></li> 722 722 </ul> 723 723 </li> 724 <li><a href="#rfc.section.1 1">11.</a> <a href="#IANA.considerations">IANA Considerations</a><ul>725 <li><a href="#rfc.section.1 1.1">11.1</a> <a href="#method.registry">Method Registry</a><ul>726 <li><a href="#rfc.section.1 1.1.1">11.1.1</a> <a href="#method.procedure">Procedure</a></li>727 <li><a href="#rfc.section.1 1.1.2">11.1.2</a> <a href="#considerations.for.new.methods">Considerations for New Methods</a></li>728 <li><a href="#rfc.section.1 1.1.3">11.1.3</a> <a href="#method.registration">Registrations</a></li>724 <li><a href="#rfc.section.12">12.</a> <a href="#IANA.considerations">IANA Considerations</a><ul> 725 <li><a href="#rfc.section.12.1">12.1</a> <a href="#method.registry">Method Registry</a><ul> 726 <li><a href="#rfc.section.12.1.1">12.1.1</a> <a href="#method.procedure">Procedure</a></li> 727 <li><a href="#rfc.section.12.1.2">12.1.2</a> <a href="#considerations.for.new.methods">Considerations for New Methods</a></li> 728 <li><a href="#rfc.section.12.1.3">12.1.3</a> <a href="#method.registration">Registrations</a></li> 729 729 </ul> 730 730 </li> 731 <li><a href="#rfc.section.1 1.2">11.2</a> <a href="#status.code.registry">Status Code Registry</a><ul>732 <li><a href="#rfc.section.1 1.2.1">11.2.1</a> <a href="#status.code.procedure">Procedure</a></li>733 <li><a href="#rfc.section.1 1.2.2">11.2.2</a> <a href="#considerations.for.new.status.codes">Considerations for New Status Codes</a></li>734 <li><a href="#rfc.section.1 1.2.3">11.2.3</a> <a href="#status.code.registration">Registrations</a></li>731 <li><a href="#rfc.section.12.2">12.2</a> <a href="#status.code.registry">Status Code Registry</a><ul> 732 <li><a href="#rfc.section.12.2.1">12.2.1</a> <a href="#status.code.procedure">Procedure</a></li> 733 <li><a href="#rfc.section.12.2.2">12.2.2</a> <a href="#considerations.for.new.status.codes">Considerations for New Status Codes</a></li> 734 <li><a href="#rfc.section.12.2.3">12.2.3</a> <a href="#status.code.registration">Registrations</a></li> 735 735 </ul> 736 736 </li> 737 <li><a href="#rfc.section.1 1.3">11.3</a> <a href="#header.field.registry">Header Field Registry</a><ul>738 <li><a href="#rfc.section.1 1.3.1">11.3.1</a> <a href="#considerations.for.new.header.fields">Considerations for New Header Fields</a></li>739 <li><a href="#rfc.section.1 1.3.2">11.3.2</a> <a href="#header.field.registration">Registrations</a></li>737 <li><a href="#rfc.section.12.3">12.3</a> <a href="#header.field.registry">Header Field Registry</a><ul> 738 <li><a href="#rfc.section.12.3.1">12.3.1</a> <a href="#considerations.for.new.header.fields">Considerations for New Header Fields</a></li> 739 <li><a href="#rfc.section.12.3.2">12.3.2</a> <a href="#header.field.registration">Registrations</a></li> 740 740 </ul> 741 741 </li> 742 <li><a href="#rfc.section.1 1.4">11.4</a> <a href="#content.coding.registry">Content Coding Registry</a><ul>743 <li><a href="#rfc.section.1 1.4.1">11.4.1</a> <a href="#content.coding.procedure">Procedure</a></li>744 <li><a href="#rfc.section.1 1.4.2">11.4.2</a> <a href="#content.coding.registration">Registrations</a></li>742 <li><a href="#rfc.section.12.4">12.4</a> <a href="#content.coding.registry">Content Coding Registry</a><ul> 743 <li><a href="#rfc.section.12.4.1">12.4.1</a> <a href="#content.coding.procedure">Procedure</a></li> 744 <li><a href="#rfc.section.12.4.2">12.4.2</a> <a href="#content.coding.registration">Registrations</a></li> 745 745 </ul> 746 746 </li> 747 747 </ul> 748 748 </li> 749 <li><a href="#rfc.section.1 2">12.</a> <a href="#security.considerations">Security Considerations</a><ul>750 <li><a href="#rfc.section.1 2.1">12.1</a> <a href="#security.sensitive">Transfer of Sensitive Information</a></li>751 <li><a href="#rfc.section.1 2.2">12.2</a> <a href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></li>752 <li><a href="#rfc.section.1 2.3">12.3</a> <a href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></li>753 <li><a href="#rfc.section.1 2.4">12.4</a> <a href="#rfc.section.12.4">Security Considerations for CONNECT</a></li>754 <li><a href="#rfc.section.1 2.5">12.5</a> <a href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></li>749 <li><a href="#rfc.section.13">13.</a> <a href="#security.considerations">Security Considerations</a><ul> 750 <li><a href="#rfc.section.13.1">13.1</a> <a href="#security.sensitive">Transfer of Sensitive Information</a></li> 751 <li><a href="#rfc.section.13.2">13.2</a> <a href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></li> 752 <li><a href="#rfc.section.13.3">13.3</a> <a href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></li> 753 <li><a href="#rfc.section.13.4">13.4</a> <a href="#rfc.section.13.4">Security Considerations for CONNECT</a></li> 754 <li><a href="#rfc.section.13.5">13.5</a> <a href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></li> 755 755 </ul> 756 756 </li> 757 <li><a href="#rfc.section.1 3">13.</a> <a href="#acks">Acknowledgments</a></li>758 <li><a href="#rfc.section.1 4">14.</a> <a href="#rfc.references">References</a><ul>759 <li><a href="#rfc.section.1 4.1">14.1</a> <a href="#rfc.references.1">Normative References</a></li>760 <li><a href="#rfc.section.1 4.2">14.2</a> <a href="#rfc.references.2">Informative References</a></li>757 <li><a href="#rfc.section.14">14.</a> <a href="#acks">Acknowledgments</a></li> 758 <li><a href="#rfc.section.15">15.</a> <a href="#rfc.references">References</a><ul> 759 <li><a href="#rfc.section.15.1">15.1</a> <a href="#rfc.references.1">Normative References</a></li> 760 <li><a href="#rfc.section.15.2">15.2</a> <a href="#rfc.references.2">Informative References</a></li> 761 761 </ul> 762 762 </li> … … 827 827 </p> 828 828 <p id="rfc.section.1.p.2">HTTP provides a uniform interface for interacting with resources regardless of their type, nature, or implementation. HTTP 829 semantics includes the intentions defined by each request method (<a href="#methods" title="Request Methods">Section 4</a>), extensions to those semantics that might be described in request header fields (<a href="#request. fields" title="Request-modifier Header Fields">Section 5.1</a>), the meaning of status codes to indicate a machine-readable response (<a href="#status.codes" title="Response Status Codes">Section 6</a>), and other control data and resource metadata that might be given in response header fields.829 semantics includes the intentions defined by each request method (<a href="#methods" title="Request Methods">Section 4</a>), extensions to those semantics that might be described in request header fields (<a href="#request.header.fields" title="Request Header Fields">Section 5</a>), the meaning of status codes to indicate a machine-readable response (<a href="#status.codes" title="Response Status Codes">Section 6</a>), and other control data and resource metadata that might be given in response header fields (<a href="#response.header.fields" title="Response Header Fields">Section 7</a>). 830 830 </p> 831 831 <p id="rfc.section.1.p.3"><span id="rfc.iref.c.1"></span> In addition, this document defines the payload of messages (a.k.a., content), the associated metadata header fields that define … … 850 850 </p> 851 851 <p id="rfc.section.2.p.3">One design goal of HTTP is to separate resource identification from request semantics, which is made possible by vesting the 852 request semantics in the request method (<a href="#methods" title="Request Methods">Section 4</a>) and a few request-modifying header fields (<a href="#request. fields" title="Request-modifier Header Fields">Section 5.1</a>). Resource owners <em class="bcp14">SHOULD NOT</em> include request semantics within a URI, such as by specifying an action to invoke within the path or query components of the852 request semantics in the request method (<a href="#methods" title="Request Methods">Section 4</a>) and a few request-modifying header fields (<a href="#request.header.fields" title="Request Header Fields">Section 5</a>). Resource owners <em class="bcp14">SHOULD NOT</em> include request semantics within a URI, such as by specifying an action to invoke within the path or query components of the 853 853 effective request URI, unless those semantics are disabled when they are inconsistent with the request method. 854 854 </p> … … 912 912 <tr> 913 913 <td class="left">Content-Encoding</td> 914 <td class="left"><a href="#header.content-encoding" id="rfc.xref.header.content-encoding.1" title="Content-Encoding">Section 1 0.6</a></td>914 <td class="left"><a href="#header.content-encoding" id="rfc.xref.header.content-encoding.1" title="Content-Encoding">Section 11.6</a></td> 915 915 </tr> 916 916 <tr> 917 917 <td class="left">Content-Language</td> 918 <td class="left"><a href="#header.content-language" id="rfc.xref.header.content-language.1" title="Content-Language">Section 1 0.7</a></td>918 <td class="left"><a href="#header.content-language" id="rfc.xref.header.content-language.1" title="Content-Language">Section 11.7</a></td> 919 919 </tr> 920 920 <tr> 921 921 <td class="left">Content-Location</td> 922 <td class="left"><a href="#header.content-location" id="rfc.xref.header.content-location.1" title="Content-Location">Section 1 0.8</a></td>922 <td class="left"><a href="#header.content-location" id="rfc.xref.header.content-location.1" title="Content-Location">Section 11.8</a></td> 923 923 </tr> 924 924 <tr> 925 925 <td class="left">Content-Type</td> 926 <td class="left"><a href="#header.content-type" id="rfc.xref.header.content-type.1" title="Content-Type">Section 1 0.9</a></td>926 <td class="left"><a href="#header.content-type" id="rfc.xref.header.content-type.1" title="Content-Type">Section 11.9</a></td> 927 927 </tr> 928 928 <tr> … … 987 987 <h2 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1</a> <a id="method.overview" href="#method.overview">Overview</a></h2> 988 988 <p id="rfc.section.4.1.p.1">The request method token is the primary source of request semantics; it indicates the purpose for which the client has made 989 this request and what is expected by the client as a successful result. The request semantics <em class="bcp14">MAY</em> be further specialized by the semantics of some header fields when present in a request (<a href="#request. fields" title="Request-modifier Header Fields">Section 5.1</a>) if those additional semantics do not conflict with the method.989 this request and what is expected by the client as a successful result. The request semantics <em class="bcp14">MAY</em> be further specialized by the semantics of some header fields when present in a request (<a href="#request.header.fields" title="Request Header Fields">Section 5</a>) if those additional semantics do not conflict with the method. 990 990 </p> 991 991 <div id="rfc.figure.u.2"></div><pre class="inline"><span id="rfc.iref.g.1"></span> <a href="#method.overview" class="smpl">method</a> = <a href="#imported.abnf" class="smpl">token</a> … … 1059 1059 </p> 1060 1060 <p id="rfc.section.4.1.p.7">Additional methods <em class="bcp14">MAY</em> be used in HTTP; many have already been standardized outside the scope of this specification and registered within the HTTP 1061 Method Registry maintained by IANA, as defined in <a href="#method.registry" title="Method Registry">Section 1 1.1</a>.1062 </p> 1063 <p id="rfc.section.4.1.p.8">The set of methods allowed by a target resource can be listed in an <a href="#header.allow" class="smpl">Allow</a> header field (<a href="#header.allow" id="rfc.xref.header.allow.1" title="Allow">Section 1 0.5</a>). However, the set of allowed methods can change dynamically. When a request message is received that is unrecognized or1061 Method Registry maintained by IANA, as defined in <a href="#method.registry" title="Method Registry">Section 12.1</a>. 1062 </p> 1063 <p id="rfc.section.4.1.p.8">The set of methods allowed by a target resource can be listed in an <a href="#header.allow" class="smpl">Allow</a> header field (<a href="#header.allow" id="rfc.xref.header.allow.1" title="Allow">Section 11.5</a>). However, the set of allowed methods can change dynamically. When a request message is received that is unrecognized or 1064 1064 not implemented by an origin server, the origin server <em class="bcp14">SHOULD</em> respond with the <a href="#status.501" class="smpl">501 (Not Implemented)</a> status code. When a request message is received that is known by an origin server but not allowed for the target resource, 1065 1065 the origin server <em class="bcp14">SHOULD</em> respond with the <a href="#status.405" class="smpl">405 (Method Not Allowed)</a> status code. … … 1136 1136 <p id="rfc.section.4.3.1.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.Part6.3"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>). 1137 1137 </p> 1138 <p id="rfc.section.4.3.1.p.7">See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section 1 2.2</a> for security considerations when used for forms.1138 <p id="rfc.section.4.3.1.p.7">See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section 13.2</a> for security considerations when used for forms. 1139 1139 </p> 1140 1140 <h3 id="rfc.section.4.3.2"><a href="#rfc.section.4.3.2">4.3.2</a> <a id="HEAD" href="#HEAD">HEAD</a></h3> … … 1168 1168 the result. 1169 1169 </p> 1170 <p id="rfc.section.4.3.3.p.4">If a resource has been created on the origin server, the response <em class="bcp14">SHOULD</em> be <a href="#status.201" class="smpl">201 (Created)</a> and contain a representation which describes the status of the request and refers to the new resource, and a <a href="#header.location" class="smpl">Location</a> header field (see <a href="#header.location" id="rfc.xref.header.location.1" title="Location">Section 1 0.13</a>).1171 </p> 1172 <p id="rfc.section.4.3.3.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 4.1.1</a> of <a href="#Part6" id="rfc.xref.Part6.5"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>). A cached POST response with a <a href="#header.content-location" class="smpl">Content-Location</a> header field (see <a href="#header.content-location" id="rfc.xref.header.content-location.2" title="Content-Location">Section 1 0.8</a>) whose value is the effective Request URI <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD requests.1170 <p id="rfc.section.4.3.3.p.4">If a resource has been created on the origin server, the response <em class="bcp14">SHOULD</em> be <a href="#status.201" class="smpl">201 (Created)</a> and contain a representation which describes the status of the request and refers to the new resource, and a <a href="#header.location" class="smpl">Location</a> header field (see <a href="#header.location" id="rfc.xref.header.location.1" title="Location">Section 11.13</a>). 1171 </p> 1172 <p id="rfc.section.4.3.3.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 4.1.1</a> of <a href="#Part6" id="rfc.xref.Part6.5"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>). A cached POST response with a <a href="#header.content-location" class="smpl">Content-Location</a> header field (see <a href="#header.content-location" id="rfc.xref.header.content-location.2" title="Content-Location">Section 11.8</a>) whose value is the effective Request URI <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD requests. 1173 1173 </p> 1174 1174 <p id="rfc.section.4.3.3.p.6">Note that POST caching is not widely implemented. However, the <a href="#status.303" class="smpl">303 (See Other)</a> response can be used to direct the user agent to retrieve a cacheable representation of the resource. … … 1317 1317 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 <a href="p1-messaging.html#header.content-length" class="smpl">Content-Length</a> field with a field-value of "0". 1318 1318 </p> 1319 <p id="rfc.section.4.3.7.p.7">The <a href="#header.max-forwards" class="smpl">Max-Forwards</a> 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 0.14</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.1319 <p id="rfc.section.4.3.7.p.7">The <a href="#header.max-forwards" class="smpl">Max-Forwards</a> 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 11.14</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. 1320 1320 </p> 1321 1321 <h3 id="rfc.section.4.3.8"><a href="#rfc.section.4.3.8">4.3.8</a> <a id="TRACE" href="#TRACE">TRACE</a></h3> 1322 1322 <div id="rfc.iref.t.1"></div> 1323 1323 <div id="rfc.iref.m.8"></div> 1324 <p id="rfc.section.4.3.8.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 <a href="#status.200" class="smpl">200 (OK)</a> response. The final recipient is either the origin server or the first proxy to receive a <a href="#header.max-forwards" class="smpl">Max-Forwards</a> 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 0.14</a>). A TRACE request <em class="bcp14">MUST NOT</em> include a message body.1324 <p id="rfc.section.4.3.8.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 <a href="#status.200" class="smpl">200 (OK)</a> response. The final recipient is either the origin server or the first proxy to receive a <a href="#header.max-forwards" class="smpl">Max-Forwards</a> value of zero (0) in the request (see <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.2" title="Max-Forwards">Section 11.14</a>). A TRACE request <em class="bcp14">MUST NOT</em> include a message body. 1325 1325 </p> 1326 1326 <p id="rfc.section.4.3.8.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 … … 1330 1330 <p id="rfc.section.4.3.8.p.3">If the request is valid, the response <em class="bcp14">SHOULD</em> have a <a href="#header.content-type" class="smpl">Content-Type</a> of "message/http" (see <a href="p1-messaging.html#internet.media.type.message.http" title="Internet Media Type message/http">Section 7.3.1</a> of <a href="#Part1" id="rfc.xref.Part1.12"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>) and contain a message body that encloses a copy of the entire request message. Responses to the TRACE method are not cacheable. 1331 1331 </p> 1332 <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a> <a id="header.fields" href="#header.fields">Header Fields</a></h1> 1333 <h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a> <a id="request.fields" href="#request.fields">Request-modifier Header Fields</a></h2> 1334 <h2 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2</a> <a id="response.fields" href="#response.fields">Status-modifier Header Fields</a></h2> 1335 <h2 id="rfc.section.5.3"><a href="#rfc.section.5.3">5.3</a> <a id="resource.fields" href="#resource.fields">Resource Metadata Fields</a></h2> 1336 <h2 id="rfc.section.5.4"><a href="#rfc.section.5.4">5.4</a> <a id="payload.fields" href="#payload.fields">Payload Metadata Fields</a></h2> 1337 <h2 id="rfc.section.5.5"><a href="#rfc.section.5.5">5.5</a> <a id="request.header.fields" href="#request.header.fields">Request Header Fields</a></h2> 1338 <p id="rfc.section.5.5.p.1">The request header fields allow the client to pass additional information about the request, and about the client itself, 1332 <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a> <a id="request.header.fields" href="#request.header.fields">Request Header Fields</a></h1> 1333 <p id="rfc.section.5.p.1">The request header fields allow the client to pass additional information about the request, and about the client itself, 1339 1334 to the server. These fields act as request modifiers, with semantics equivalent to the parameters on a programming language 1340 1335 method invocation. … … 1351 1346 <tr> 1352 1347 <td class="left">Accept</td> 1353 <td class="left"><a href="#header.accept" id="rfc.xref.header.accept.1" title="Accept">Section 1 0.1</a></td>1348 <td class="left"><a href="#header.accept" id="rfc.xref.header.accept.1" title="Accept">Section 11.1</a></td> 1354 1349 </tr> 1355 1350 <tr> 1356 1351 <td class="left">Accept-Charset</td> 1357 <td class="left"><a href="#header.accept-charset" id="rfc.xref.header.accept-charset.1" title="Accept-Charset">Section 1 0.2</a></td>1352 <td class="left"><a href="#header.accept-charset" id="rfc.xref.header.accept-charset.1" title="Accept-Charset">Section 11.2</a></td> 1358 1353 </tr> 1359 1354 <tr> 1360 1355 <td class="left">Accept-Encoding</td> 1361 <td class="left"><a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.1" title="Accept-Encoding">Section 1 0.3</a></td>1356 <td class="left"><a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.1" title="Accept-Encoding">Section 11.3</a></td> 1362 1357 </tr> 1363 1358 <tr> 1364 1359 <td class="left">Accept-Language</td> 1365 <td class="left"><a href="#header.accept-language" id="rfc.xref.header.accept-language.1" title="Accept-Language">Section 1 0.4</a></td>1360 <td class="left"><a href="#header.accept-language" id="rfc.xref.header.accept-language.1" title="Accept-Language">Section 11.4</a></td> 1366 1361 </tr> 1367 1362 <tr> … … 1371 1366 <tr> 1372 1367 <td class="left">Expect</td> 1373 <td class="left"><a href="#header.expect" id="rfc.xref.header.expect.1" title="Expect">Section 1 0.11</a></td>1368 <td class="left"><a href="#header.expect" id="rfc.xref.header.expect.1" title="Expect">Section 11.11</a></td> 1374 1369 </tr> 1375 1370 <tr> 1376 1371 <td class="left">From</td> 1377 <td class="left"><a href="#header.from" id="rfc.xref.header.from.1" title="From">Section 1 0.12</a></td>1372 <td class="left"><a href="#header.from" id="rfc.xref.header.from.1" title="From">Section 11.12</a></td> 1378 1373 </tr> 1379 1374 <tr> … … 1403 1398 <tr> 1404 1399 <td class="left">Max-Forwards</td> 1405 <td class="left"><a href="#header.max-forwards" id="rfc.xref.header.max-forwards.3" title="Max-Forwards">Section 1 0.14</a></td>1400 <td class="left"><a href="#header.max-forwards" id="rfc.xref.header.max-forwards.3" title="Max-Forwards">Section 11.14</a></td> 1406 1401 </tr> 1407 1402 <tr> … … 1415 1410 <tr> 1416 1411 <td class="left">Referer</td> 1417 <td class="left"><a href="#header.referer" id="rfc.xref.header.referer.1" title="Referer">Section 1 0.15</a></td>1412 <td class="left"><a href="#header.referer" id="rfc.xref.header.referer.1" title="Referer">Section 11.15</a></td> 1418 1413 </tr> 1419 1414 <tr> … … 1423 1418 <tr> 1424 1419 <td class="left">User-Agent</td> 1425 <td class="left"><a href="#header.user-agent" id="rfc.xref.header.user-agent.1" title="User-Agent">Section 1 0.18</a></td>1420 <td class="left"><a href="#header.user-agent" id="rfc.xref.header.user-agent.1" title="User-Agent">Section 11.18</a></td> 1426 1421 </tr> 1427 1422 </tbody> 1428 1423 </table> 1429 1424 </div> 1430 <h2 id="rfc.section.5.6"><a href="#rfc.section.5.6">5.6</a> <a id="response.header.fields" href="#response.header.fields">Response Header Fields</a></h2> 1431 <p id="rfc.section.5.6.p.1">The response header fields allow the server to pass additional information about the response which cannot be placed in the 1432 status-line. These header fields give information about the server and about further access to the target resource (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 5.5</a> of <a href="#Part1" id="rfc.xref.Part1.15"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). 1433 </p> 1434 <div id="rfc.table.u.4"> 1435 <table class="tt full left" cellpadding="3" cellspacing="0"> 1436 <thead> 1437 <tr> 1438 <th>Header Field Name</th> 1439 <th>Defined in...</th> 1440 </tr> 1441 </thead> 1442 <tbody> 1443 <tr> 1444 <td class="left">Accept-Ranges</td> 1445 <td class="left"><a href="p5-range.html#header.accept-ranges" title="Accept-Ranges">Section 5.1</a> of <a href="#Part5" id="rfc.xref.Part5.6"><cite title="HTTP/1.1, part 5: Range Requests">[Part5]</cite></a></td> 1446 </tr> 1447 <tr> 1448 <td class="left">Age</td> 1449 <td class="left"><a href="p6-cache.html#header.age" title="Age">Section 7.1</a> of <a href="#Part6" id="rfc.xref.Part6.8"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a></td> 1450 </tr> 1451 <tr> 1452 <td class="left">Allow</td> 1453 <td class="left"><a href="#header.allow" id="rfc.xref.header.allow.2" title="Allow">Section 10.5</a></td> 1454 </tr> 1455 <tr> 1456 <td class="left">Date</td> 1457 <td class="left"><a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section 10.10</a></td> 1458 </tr> 1459 <tr> 1460 <td class="left">ETag</td> 1461 <td class="left"><a href="p4-conditional.html#header.etag" title="ETag">Section 2.3</a> of <a href="#Part4" id="rfc.xref.Part4.8"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a></td> 1462 </tr> 1463 <tr> 1464 <td class="left">Location</td> 1465 <td class="left"><a href="#header.location" id="rfc.xref.header.location.2" title="Location">Section 10.13</a></td> 1466 </tr> 1467 <tr> 1468 <td class="left">Proxy-Authenticate</td> 1469 <td class="left"><a href="p7-auth.html#header.proxy-authenticate" title="Proxy-Authenticate">Section 4.2</a> of <a href="#Part7" id="rfc.xref.Part7.3"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a></td> 1470 </tr> 1471 <tr> 1472 <td class="left">Retry-After</td> 1473 <td class="left"><a href="#header.retry-after" id="rfc.xref.header.retry-after.1" title="Retry-After">Section 10.16</a></td> 1474 </tr> 1475 <tr> 1476 <td class="left">Server</td> 1477 <td class="left"><a href="#header.server" id="rfc.xref.header.server.1" title="Server">Section 10.17</a></td> 1478 </tr> 1479 <tr> 1480 <td class="left">Vary</td> 1481 <td class="left"><a href="p6-cache.html#header.vary" title="Vary">Section 7.5</a> of <a href="#Part6" id="rfc.xref.Part6.9"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a></td> 1482 </tr> 1483 <tr> 1484 <td class="left">WWW-Authenticate</td> 1485 <td class="left"><a href="p7-auth.html#header.www-authenticate" title="WWW-Authenticate">Section 4.4</a> of <a href="#Part7" id="rfc.xref.Part7.4"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a></td> 1486 </tr> 1487 </tbody> 1488 </table> 1489 </div> 1425 <h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a> <a id="request.controls" href="#request.controls">Controls</a></h2> 1426 <h2 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2</a> <a id="request.conditionals" href="#request.conditionals">Conditionals</a></h2> 1427 <h2 id="rfc.section.5.3"><a href="#rfc.section.5.3">5.3</a> <a id="request.conneg" href="#request.conneg">Content Negotiation</a></h2> 1428 <h2 id="rfc.section.5.4"><a href="#rfc.section.5.4">5.4</a> <a id="request.inform" href="#request.inform">Information</a></h2> 1490 1429 <h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a> <a id="status.codes" href="#status.codes">Response Status Codes</a></h1> 1491 1430 <p id="rfc.section.6.p.1">The status-code element is a 3-digit integer result code of the attempt to understand and satisfy the request.</p> … … 1511 1450 </li> 1512 1451 </ul> 1513 <p id="rfc.section.6.p.4">For most status codes the response can carry a payload, in which case a <a href="#header.content-type" class="smpl">Content-Type</a> header field indicates the payload's media type (<a href="#header.content-type" id="rfc.xref.header.content-type.2" title="Content-Type">Section 1 0.9</a>).1452 <p id="rfc.section.6.p.4">For most status codes the response can carry a payload, in which case a <a href="#header.content-type" class="smpl">Content-Type</a> header field indicates the payload's media type (<a href="#header.content-type" id="rfc.xref.header.content-type.2" title="Content-Type">Section 11.9</a>). 1514 1453 </p> 1515 1454 <h2 id="rfc.section.6.1"><a href="#rfc.section.6.1">6.1</a> <a id="overview.of.status.codes" href="#overview.of.status.codes">Overview of Status Codes</a></h2> 1516 <p id="rfc.section.6.1.p.1">The status codes listed below are defined in this specification, <a href="p4-conditional.html#status.code.definitions" title="Status Code Definitions">Section 4</a> of <a href="#Part4" id="rfc.xref.Part4. 9"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>, <a href="p5-range.html#status.code.definitions" title="Status Code Definitions">Section 3</a> of <a href="#Part5" id="rfc.xref.Part5.7"><cite title="HTTP/1.1, part 5: Range Requests">[Part5]</cite></a>, and <a href="p7-auth.html#status.code.definitions" title="Status Code Definitions">Section 3</a> of <a href="#Part7" id="rfc.xref.Part7.5"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a>. The reason phrases listed here are only recommendations — they can be replaced by local equivalents without affecting the1455 <p id="rfc.section.6.1.p.1">The status codes listed below are defined in this specification, <a href="p4-conditional.html#status.code.definitions" title="Status Code Definitions">Section 4</a> of <a href="#Part4" id="rfc.xref.Part4.8"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>, <a href="p5-range.html#status.code.definitions" title="Status Code Definitions">Section 3</a> of <a href="#Part5" id="rfc.xref.Part5.6"><cite title="HTTP/1.1, part 5: Range Requests">[Part5]</cite></a>, and <a href="p7-auth.html#status.code.definitions" title="Status Code Definitions">Section 3</a> of <a href="#Part7" id="rfc.xref.Part7.3"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a>. The reason phrases listed here are only recommendations — they can be replaced by local equivalents without affecting the 1517 1456 protocol. 1518 1457 </p> 1519 <div id="rfc.table.u. 5">1458 <div id="rfc.table.u.4"> 1520 1459 <table class="tt full left" cellpadding="3" cellspacing="0"> 1521 1460 <thead> … … 1570 1509 <td class="left">206</td> 1571 1510 <td class="left">Partial Content</td> 1572 <td id="status.206" class="left"><a href="p5-range.html#status.206" title="206 Partial Content">Section 3.1</a> of <a href="#Part5" id="rfc.xref.Part5. 8"><cite title="HTTP/1.1, part 5: Range Requests">[Part5]</cite></a></td>1511 <td id="status.206" class="left"><a href="p5-range.html#status.206" title="206 Partial Content">Section 3.1</a> of <a href="#Part5" id="rfc.xref.Part5.7"><cite title="HTTP/1.1, part 5: Range Requests">[Part5]</cite></a></td> 1573 1512 </tr> 1574 1513 <tr> … … 1595 1534 <td class="left">304</td> 1596 1535 <td class="left">Not Modified</td> 1597 <td id="status.304" class="left"><a href="p4-conditional.html#status.304" title="304 Not Modified">Section 4.1</a> of <a href="#Part4" id="rfc.xref.Part4. 10"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a></td>1536 <td id="status.304" class="left"><a href="p4-conditional.html#status.304" title="304 Not Modified">Section 4.1</a> of <a href="#Part4" id="rfc.xref.Part4.9"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a></td> 1598 1537 </tr> 1599 1538 <tr> … … 1615 1554 <td class="left">401</td> 1616 1555 <td class="left">Unauthorized</td> 1617 <td id="status.401" class="left"><a href="p7-auth.html#status.401" title="401 Unauthorized">Section 3.1</a> of <a href="#Part7" id="rfc.xref.Part7. 6"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a></td>1556 <td id="status.401" class="left"><a href="p7-auth.html#status.401" title="401 Unauthorized">Section 3.1</a> of <a href="#Part7" id="rfc.xref.Part7.4"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a></td> 1618 1557 </tr> 1619 1558 <tr> … … 1645 1584 <td class="left">407</td> 1646 1585 <td class="left">Proxy Authentication Required</td> 1647 <td id="status.407" class="left"><a href="p7-auth.html#status.407" title="407 Proxy Authentication Required">Section 3.2</a> of <a href="#Part7" id="rfc.xref.Part7. 7"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a></td>1586 <td id="status.407" class="left"><a href="p7-auth.html#status.407" title="407 Proxy Authentication Required">Section 3.2</a> of <a href="#Part7" id="rfc.xref.Part7.5"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a></td> 1648 1587 </tr> 1649 1588 <tr> … … 1670 1609 <td class="left">412</td> 1671 1610 <td class="left">Precondition Failed</td> 1672 <td id="status.412" class="left"><a href="p4-conditional.html#status.412" title="412 Precondition Failed">Section 4.2</a> of <a href="#Part4" id="rfc.xref.Part4.1 1"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a></td>1611 <td id="status.412" class="left"><a href="p4-conditional.html#status.412" title="412 Precondition Failed">Section 4.2</a> of <a href="#Part4" id="rfc.xref.Part4.10"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a></td> 1673 1612 </tr> 1674 1613 <tr> … … 1690 1629 <td class="left">416</td> 1691 1630 <td class="left">Requested range not satisfiable</td> 1692 <td id="status.416" class="left"><a href="p5-range.html#status.416" title="416 Requested Range Not Satisfiable">Section 3.2</a> of <a href="#Part5" id="rfc.xref.Part5. 9"><cite title="HTTP/1.1, part 5: Range Requests">[Part5]</cite></a></td>1631 <td id="status.416" class="left"><a href="p5-range.html#status.416" title="416 Requested Range Not Satisfiable">Section 3.2</a> of <a href="#Part5" id="rfc.xref.Part5.8"><cite title="HTTP/1.1, part 5: Range Requests">[Part5]</cite></a></td> 1693 1632 </tr> 1694 1633 <tr> … … 1755 1694 <p id="rfc.section.6.2.1.p.1">The client <em class="bcp14">SHOULD</em> continue with its request. This interim response is used to inform the client that the initial part of the request has been 1756 1695 received and has not yet been rejected by the server. The client <em class="bcp14">SHOULD</em> continue by sending the remainder of the request or, if the request has already been completed, ignore this response. The 1757 server <em class="bcp14">MUST</em> send a final response after the request has been completed. See <a href="p1-messaging.html#use.of.the.100.status" title="Use of the 100 (Continue) Status">Section 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.1 6"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a> for detailed discussion of the use and handling of this status code.1696 server <em class="bcp14">MUST</em> send a final response after the request has been completed. See <a href="p1-messaging.html#use.of.the.100.status" title="Use of the 100 (Continue) Status">Section 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.15"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a> for detailed discussion of the use and handling of this status code. 1758 1697 </p> 1759 1698 <div id="rfc.iref.25"></div> 1760 1699 <div id="rfc.iref.s.5"></div> 1761 1700 <h3 id="rfc.section.6.2.2"><a href="#rfc.section.6.2.2">6.2.2</a> <a id="status.101" href="#status.101">101 Switching Protocols</a></h3> 1762 <p id="rfc.section.6.2.2.p.1">The server understands and is willing to comply with the client's request, via the <a href="p1-messaging.html#header.upgrade" class="smpl">Upgrade</a> message header field (<a href="p1-messaging.html#header.upgrade" title="Upgrade">Section 6.4</a> of <a href="#Part1" id="rfc.xref.Part1.1 7"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>), for a change in the application protocol being used on this connection. The server will switch protocols to those defined1701 <p id="rfc.section.6.2.2.p.1">The server understands and is willing to comply with the client's request, via the <a href="p1-messaging.html#header.upgrade" class="smpl">Upgrade</a> message header field (<a href="p1-messaging.html#header.upgrade" title="Upgrade">Section 6.4</a> of <a href="#Part1" id="rfc.xref.Part1.16"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>), for a change in the application protocol being used on this connection. The server will switch protocols to those defined 1763 1702 by the response's Upgrade header field immediately after the empty line which terminates the 101 response. 1764 1703 </p> … … 1785 1724 <dd>a representation containing the request message as received by the end server.</dd> 1786 1725 </dl> 1787 <p id="rfc.section.6.3.1.p.2">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6. 10"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 200 responses.1726 <p id="rfc.section.6.3.1.p.2">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.8"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 200 responses. 1788 1727 </p> 1789 1728 <div id="rfc.iref.28"></div> … … 1798 1737 </p> 1799 1738 <p id="rfc.section.6.3.2.p.4">A 201 response <em class="bcp14">MAY</em> contain an <a href="p4-conditional.html#header.etag" class="smpl">ETag</a> response header field indicating the current value of the entity-tag for the representation of the resource identified by 1800 the <a href="#header.location" class="smpl">Location</a> header field or, in case the Location header field was omitted, by the Effective Request URI (see <a href="p4-conditional.html#header.etag" title="ETag">Section 2.3</a> of <a href="#Part4" id="rfc.xref.Part4.1 2"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>).1739 the <a href="#header.location" class="smpl">Location</a> header field or, in case the Location header field was omitted, by the Effective Request URI (see <a href="p4-conditional.html#header.etag" title="ETag">Section 2.3</a> of <a href="#Part4" id="rfc.xref.Part4.11"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>). 1801 1740 </p> 1802 1741 <div id="rfc.iref.29"></div> … … 1815 1754 <div id="rfc.iref.s.10"></div> 1816 1755 <h3 id="rfc.section.6.3.4"><a href="#rfc.section.6.3.4">6.3.4</a> <a id="status.203" href="#status.203">203 Non-Authoritative Information</a></h3> 1817 <p id="rfc.section.6.3.4.p.1">The representation in the response has been transformed or otherwise modified by a transforming proxy (<a href="p1-messaging.html#intermediaries" title="Intermediaries">Section 2.3</a> of <a href="#Part1" id="rfc.xref.Part1.1 8"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). Note that the behavior of transforming intermediaries is controlled by the no-transform Cache-Control directive (<a href="p6-cache.html#header.cache-control" title="Cache-Control">Section 7.2</a> of <a href="#Part6" id="rfc.xref.Part6.11"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>).1756 <p id="rfc.section.6.3.4.p.1">The representation in the response has been transformed or otherwise modified by a transforming proxy (<a href="p1-messaging.html#intermediaries" title="Intermediaries">Section 2.3</a> of <a href="#Part1" id="rfc.xref.Part1.17"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). Note that the behavior of transforming intermediaries is controlled by the no-transform Cache-Control directive (<a href="p6-cache.html#header.cache-control" title="Cache-Control">Section 7.2</a> of <a href="#Part6" id="rfc.xref.Part6.9"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>). 1818 1757 </p> 1819 1758 <p id="rfc.section.6.3.4.p.2">This status code is only appropriate when the response status code would have been <a href="#status.200" class="smpl">200 (OK)</a> otherwise. When the status code before transformation would have been different, the 214 Transformation Applied warn-code 1820 (<a href="p6-cache.html#header.warning" title="Warning">Section 7.6</a> of <a href="#Part6" id="rfc.xref.Part6.1 2"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) is appropriate.1821 </p> 1822 <p id="rfc.section.6.3.4.p.3">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.1 3"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 203 responses.1759 (<a href="p6-cache.html#header.warning" title="Warning">Section 7.6</a> of <a href="#Part6" id="rfc.xref.Part6.10"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) is appropriate. 1760 </p> 1761 <p id="rfc.section.6.3.4.p.3">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.11"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 203 responses. 1823 1762 </p> 1824 1763 <div id="rfc.iref.31"></div> … … 1850 1789 another input action. 1851 1790 </p> 1852 <p id="rfc.section.6.3.6.p.2">The message body included with the response <em class="bcp14">MUST</em> be empty. Note that receivers still need to parse the response according to the algorithm defined in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.1 9"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>.1791 <p id="rfc.section.6.3.6.p.2">The message body included with the response <em class="bcp14">MUST</em> be empty. Note that receivers still need to parse the response according to the algorithm defined in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.18"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>. 1853 1792 </p> 1854 1793 <h2 id="rfc.section.6.4"><a href="#rfc.section.6.4">6.4</a> <a id="status.3xx" href="#status.3xx">Redirection 3xx</a></h2> … … 1873 1812 </li> 1874 1813 <li> 1875 <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 <a href="#status.300" class="smpl">300 (Multiple Choices)</a>.1814 <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 <a href="#status.300" class="smpl">300 (Multiple Choices)</a>. 1876 1815 </p> 1877 1816 </li> 1878 1817 <li> 1879 1818 <p>Other kinds of redirection, such as to a cached result (status code <a href="p4-conditional.html#status.304" class="smpl">304 1880 (Not Modified)</a>, see <a href="p4-conditional.html#status.304" title="304 Not Modified">Section 4.1</a> of <a href="#Part4" id="rfc.xref.Part4.1 3"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>).1819 (Not Modified)</a>, see <a href="p4-conditional.html#status.304" title="304 Not Modified">Section 4.1</a> of <a href="#Part4" id="rfc.xref.Part4.12"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>). 1881 1820 </p> 1882 1821 </li> … … 1888 1827 </p> 1889 1828 </div> 1890 <p id="rfc.section.6.4.p.4">A <a href="#header.location" class="smpl">Location</a> 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 10.13</a>.1829 <p id="rfc.section.6.4.p.4">A <a href="#header.location" class="smpl">Location</a> 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.2" title="Location">Section 11.13</a>. 1891 1830 </p> 1892 1831 <p id="rfc.section.6.4.p.5">Note that for methods not known to be "safe", as defined in <a href="#safe.methods" title="Safe Methods">Section 4.2.1</a>, automatic redirection needs to done with care, since the redirect might change the conditions under which the request was … … 1903 1842 <h3 id="rfc.section.6.4.1"><a href="#rfc.section.6.4.1">6.4.1</a> <a id="status.300" href="#status.300">300 Multiple Choices</a></h3> 1904 1843 <p id="rfc.section.6.4.1.p.1">The target resource has more than one representation, each with its own specific location, and agent-driven negotiation information 1905 (<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 that1844 (<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 that 1906 1845 location. 1907 1846 </p> … … 1912 1851 <p id="rfc.section.6.4.1.p.3">If the server has a preferred choice of representation, it <em class="bcp14">SHOULD</em> include the specific URI for that representation in the <a href="#header.location" class="smpl">Location</a> field; user agents <em class="bcp14">MAY</em> use the Location field value for automatic redirection. 1913 1852 </p> 1914 <p id="rfc.section.6.4.1.p.4">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.1 4"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 300 responses.1853 <p id="rfc.section.6.4.1.p.4">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.12"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 300 responses. 1915 1854 </p> 1916 1855 <div id="rfc.iref.35"></div> … … 1920 1859 request URI to one or more of the new references returned by the server, where possible. 1921 1860 </p> 1922 <p id="rfc.section.6.4.2.p.2">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.1 5"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 301 responses.1861 <p id="rfc.section.6.4.2.p.2">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.13"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 301 responses. 1923 1862 </p> 1924 1863 <p id="rfc.section.6.4.2.p.3">The new permanent URI <em class="bcp14">SHOULD</em> be given by the <a href="#header.location" class="smpl">Location</a> field in the response. A response payload can contain a short hypertext note with a hyperlink to the new URI(s). … … 2069 2008 — that is left to the discretion of the server owner. 2070 2009 </p> 2071 <p id="rfc.section.6.5.9.p.3">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.1 6"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 410 responses.2010 <p id="rfc.section.6.5.9.p.3">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.14"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 410 responses. 2072 2011 </p> 2073 2012 <div id="rfc.iref.51"></div> … … 2103 2042 <div id="rfc.iref.s.35"></div> 2104 2043 <h3 id="rfc.section.6.5.14"><a href="#rfc.section.6.5.14">6.5.14</a> <a id="status.417" href="#status.417">417 Expectation Failed</a></h3> 2105 <p id="rfc.section.6.5.14.p.1">The expectation given in an <a href="#header.expect" class="smpl">Expect</a> header field (see <a href="#header.expect" id="rfc.xref.header.expect.2" title="Expect">Section 1 0.11</a>) could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could2044 <p id="rfc.section.6.5.14.p.1">The expectation given in an <a href="#header.expect" class="smpl">Expect</a> header field (see <a href="#header.expect" id="rfc.xref.header.expect.2" title="Expect">Section 11.11</a>) could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could 2106 2045 not be met by the next-hop server. 2107 2046 </p> … … 2109 2048 <div id="rfc.iref.s.36"></div> 2110 2049 <h3 id="rfc.section.6.5.15"><a href="#rfc.section.6.5.15">6.5.15</a> <a id="status.426" href="#status.426">426 Upgrade Required</a></h3> 2111 <p id="rfc.section.6.5.15.p.1">The request can not be completed without a prior protocol upgrade. This response <em class="bcp14">MUST</em> include an <a href="p1-messaging.html#header.upgrade" class="smpl">Upgrade</a> header field (<a href="p1-messaging.html#header.upgrade" title="Upgrade">Section 6.4</a> of <a href="#Part1" id="rfc.xref.Part1. 20"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>) specifying the required protocols.2050 <p id="rfc.section.6.5.15.p.1">The request can not be completed without a prior protocol upgrade. This response <em class="bcp14">MUST</em> include an <a href="p1-messaging.html#header.upgrade" class="smpl">Upgrade</a> header field (<a href="p1-messaging.html#header.upgrade" title="Upgrade">Section 6.4</a> of <a href="#Part1" id="rfc.xref.Part1.19"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>) specifying the required protocols. 2112 2051 </p> 2113 2052 <div id="rfc.figure.u.5"></div> … … 2150 2089 <p id="rfc.section.6.6.4.p.1">The server is currently unable to handle the request due to a temporary overloading or maintenance of the server.</p> 2151 2090 <p id="rfc.section.6.6.4.p.2">The implication is that this is a temporary condition which will be alleviated after some delay. If known, the length of the 2152 delay <em class="bcp14">MAY</em> be indicated in a <a href="#header.retry-after" class="smpl">Retry-After</a> header field (<a href="#header.retry-after" id="rfc.xref.header.retry-after. 2" title="Retry-After">Section 10.16</a>). If no Retry-After is given, the client <em class="bcp14">SHOULD</em> handle the response as it would for a <a href="#status.500" class="smpl">500 (Internal2091 delay <em class="bcp14">MAY</em> be indicated in a <a href="#header.retry-after" class="smpl">Retry-After</a> header field (<a href="#header.retry-after" id="rfc.xref.header.retry-after.1" title="Retry-After">Section 11.16</a>). If no Retry-After is given, the client <em class="bcp14">SHOULD</em> handle the response as it would for a <a href="#status.500" class="smpl">500 (Internal 2153 2092 Server Error)</a> response. 2154 2093 </p> … … 2174 2113 <p id="rfc.section.6.6.6.p.1">The server does not support, or refuses to support, the protocol version that was used in the request message. The server 2175 2114 is indicating that it is unable or unwilling to complete the request using the same major version as the client, as described 2176 in <a href="p1-messaging.html#http.version" title="Protocol Versioning">Section 2.6</a> of <a href="#Part1" id="rfc.xref.Part1.21"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>, other than with this error message. The response <em class="bcp14">SHOULD</em> contain a representation describing why that version is not supported and what other protocols are supported by that server. 2177 </p> 2178 <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a> <a id="protocol.parameters" href="#protocol.parameters">Protocol Parameters</a></h1> 2179 <h2 id="rfc.section.7.1"><a href="#rfc.section.7.1">7.1</a> <a id="http.date" href="#http.date">Date/Time Formats</a></h2> 2180 <p id="rfc.section.7.1.p.1">HTTP applications have historically allowed three different formats for date/time stamps. However, the preferred format is 2115 in <a href="p1-messaging.html#http.version" title="Protocol Versioning">Section 2.6</a> of <a href="#Part1" id="rfc.xref.Part1.20"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>, other than with this error message. The response <em class="bcp14">SHOULD</em> contain a representation describing why that version is not supported and what other protocols are supported by that server. 2116 </p> 2117 <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a> <a id="response.header.fields" href="#response.header.fields">Response Header Fields</a></h1> 2118 <p id="rfc.section.7.p.1">The response header fields allow the server to pass additional information about the response which cannot be placed in the 2119 status-line. These header fields give information about the server and about further access to the target resource (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 5.5</a> of <a href="#Part1" id="rfc.xref.Part1.21"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). 2120 </p> 2121 <div id="rfc.table.u.5"> 2122 <table class="tt full left" cellpadding="3" cellspacing="0"> 2123 <thead> 2124 <tr> 2125 <th>Header Field Name</th> 2126 <th>Defined in...</th> 2127 </tr> 2128 </thead> 2129 <tbody> 2130 <tr> 2131 <td class="left">Accept-Ranges</td> 2132 <td class="left"><a href="p5-range.html#header.accept-ranges" title="Accept-Ranges">Section 5.1</a> of <a href="#Part5" id="rfc.xref.Part5.9"><cite title="HTTP/1.1, part 5: Range Requests">[Part5]</cite></a></td> 2133 </tr> 2134 <tr> 2135 <td class="left">Age</td> 2136 <td class="left"><a href="p6-cache.html#header.age" title="Age">Section 7.1</a> of <a href="#Part6" id="rfc.xref.Part6.15"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a></td> 2137 </tr> 2138 <tr> 2139 <td class="left">Allow</td> 2140 <td class="left"><a href="#header.allow" id="rfc.xref.header.allow.2" title="Allow">Section 11.5</a></td> 2141 </tr> 2142 <tr> 2143 <td class="left">Date</td> 2144 <td class="left"><a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section 11.10</a></td> 2145 </tr> 2146 <tr> 2147 <td class="left">ETag</td> 2148 <td class="left"><a href="p4-conditional.html#header.etag" title="ETag">Section 2.3</a> of <a href="#Part4" id="rfc.xref.Part4.13"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a></td> 2149 </tr> 2150 <tr> 2151 <td class="left">Location</td> 2152 <td class="left"><a href="#header.location" id="rfc.xref.header.location.3" title="Location">Section 11.13</a></td> 2153 </tr> 2154 <tr> 2155 <td class="left">Proxy-Authenticate</td> 2156 <td class="left"><a href="p7-auth.html#header.proxy-authenticate" title="Proxy-Authenticate">Section 4.2</a> of <a href="#Part7" id="rfc.xref.Part7.6"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a></td> 2157 </tr> 2158 <tr> 2159 <td class="left">Retry-After</td> 2160 <td class="left"><a href="#header.retry-after" id="rfc.xref.header.retry-after.2" title="Retry-After">Section 11.16</a></td> 2161 </tr> 2162 <tr> 2163 <td class="left">Server</td> 2164 <td class="left"><a href="#header.server" id="rfc.xref.header.server.1" title="Server">Section 11.17</a></td> 2165 </tr> 2166 <tr> 2167 <td class="left">Vary</td> 2168 <td class="left"><a href="p6-cache.html#header.vary" title="Vary">Section 7.5</a> of <a href="#Part6" id="rfc.xref.Part6.16"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a></td> 2169 </tr> 2170 <tr> 2171 <td class="left">WWW-Authenticate</td> 2172 <td class="left"><a href="p7-auth.html#header.www-authenticate" title="WWW-Authenticate">Section 4.4</a> of <a href="#Part7" id="rfc.xref.Part7.7"><cite title="HTTP/1.1, part 7: Authentication">[Part7]</cite></a></td> 2173 </tr> 2174 </tbody> 2175 </table> 2176 </div> 2177 <h1 id="rfc.section.8"><a href="#rfc.section.8">8.</a> <a id="protocol.parameters" href="#protocol.parameters">Protocol Parameters</a></h1> 2178 <h2 id="rfc.section.8.1"><a href="#rfc.section.8.1">8.1</a> <a id="http.date" href="#http.date">Date/Time Formats</a></h2> 2179 <p id="rfc.section.8.1.p.1">HTTP applications have historically allowed three different formats for date/time stamps. However, the preferred format is 2181 2180 a fixed-length subset of that defined by <a href="#RFC1123" id="rfc.xref.RFC1123.1"><cite title="Requirements for Internet Hosts - Application and Support">[RFC1123]</cite></a>: 2182 2181 </p> 2183 2182 <div id="rfc.figure.u.6"></div><pre class="text">Sun, 06 Nov 1994 08:49:37 GMT ; RFC 1123 2184 </pre><p id="rfc.section. 7.1.p.3">The other formats are described here only for compatibility with obsolete implementations.</p>2183 </pre><p id="rfc.section.8.1.p.3">The other formats are described here only for compatibility with obsolete implementations.</p> 2185 2184 <div id="rfc.figure.u.7"></div><pre class="text">Sunday, 06-Nov-94 08:49:37 GMT ; obsolete RFC 850 format 2186 2185 Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format 2187 </pre><p id="rfc.section. 7.1.p.5">HTTP/1.1 clients and servers that parse a date value <em class="bcp14">MUST</em> accept all three formats (for compatibility with HTTP/1.0), though they <em class="bcp14">MUST</em> only generate the RFC 1123 format for representing HTTP-date values in header fields.2188 </p> 2189 <p id="rfc.section. 7.1.p.6">All HTTP date/time stamps <em class="bcp14">MUST</em> be represented in Greenwich Mean Time (GMT), without exception. For the purposes of HTTP, GMT is exactly equal to UTC (Coordinated2186 </pre><p id="rfc.section.8.1.p.5">HTTP/1.1 clients and servers that parse a date value <em class="bcp14">MUST</em> accept all three formats (for compatibility with HTTP/1.0), though they <em class="bcp14">MUST</em> only generate the RFC 1123 format for representing HTTP-date values in header fields. 2187 </p> 2188 <p id="rfc.section.8.1.p.6">All HTTP date/time stamps <em class="bcp14">MUST</em> be represented in Greenwich Mean Time (GMT), without exception. For the purposes of HTTP, GMT is exactly equal to UTC (Coordinated 2190 2189 Universal Time). This is indicated in the first two formats by the inclusion of "GMT" as the three-letter abbreviation for 2191 2190 time zone, and <em class="bcp14">MUST</em> be assumed when reading the asctime format. HTTP-date is case sensitive and <em class="bcp14">MUST NOT</em> include additional whitespace beyond that specifically included as SP in the grammar. … … 2193 2192 <div id="rfc.figure.u.8"></div><pre class="inline"><span id="rfc.iref.g.3"></span> <a href="#http.date" class="smpl">HTTP-date</a> = <a href="#preferred.date.format" class="smpl">rfc1123-date</a> / <a href="#obsolete.date.formats" class="smpl">obs-date</a> 2194 2193 </pre><div id="preferred.date.format"> 2195 <p id="rfc.section. 7.1.p.8"> Preferred format:</p>2194 <p id="rfc.section.8.1.p.8"> Preferred format:</p> 2196 2195 </div> 2197 2196 <div id="rfc.figure.u.9"></div><pre class="inline"><span id="rfc.iref.g.4"></span><span id="rfc.iref.g.5"></span><span id="rfc.iref.g.6"></span><span id="rfc.iref.g.7"></span><span id="rfc.iref.g.8"></span><span id="rfc.iref.g.9"></span><span id="rfc.iref.g.10"></span><span id="rfc.iref.g.11"></span><span id="rfc.iref.g.12"></span><span id="rfc.iref.g.13"></span><span id="rfc.iref.g.14"></span><span id="rfc.iref.g.15"></span> <a href="#preferred.date.format" class="smpl">rfc1123-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> "," <a href="#imported.abnf" class="smpl">SP</a> date1 <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a> … … 2233 2232 <a href="#preferred.date.format" class="smpl">minute</a> = 2<a href="#imported.abnf" class="smpl">DIGIT</a> 2234 2233 <a href="#preferred.date.format" class="smpl">second</a> = 2<a href="#imported.abnf" class="smpl">DIGIT</a> 2235 </pre><p id="rfc.section. 7.1.p.10">The semantics of <a href="#preferred.date.format" class="smpl">day-name</a>, <a href="#preferred.date.format" class="smpl">day</a>, <a href="#preferred.date.format" class="smpl">month</a>, <a href="#preferred.date.format" class="smpl">year</a>, and <a href="#preferred.date.format" class="smpl">time-of-day</a> are the same as those defined for the RFC 5322 constructs with the corresponding name (<a href="#RFC5322" id="rfc.xref.RFC5322.1"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.3">Section 3.3</a>).2234 </pre><p id="rfc.section.8.1.p.10">The semantics of <a href="#preferred.date.format" class="smpl">day-name</a>, <a href="#preferred.date.format" class="smpl">day</a>, <a href="#preferred.date.format" class="smpl">month</a>, <a href="#preferred.date.format" class="smpl">year</a>, and <a href="#preferred.date.format" class="smpl">time-of-day</a> are the same as those defined for the RFC 5322 constructs with the corresponding name (<a href="#RFC5322" id="rfc.xref.RFC5322.1"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.3">Section 3.3</a>). 2236 2235 </p> 2237 2236 <div id="obsolete.date.formats"> 2238 <p id="rfc.section. 7.1.p.11"> Obsolete formats:</p>2237 <p id="rfc.section.8.1.p.11"> Obsolete formats:</p> 2239 2238 </div> 2240 2239 <div id="rfc.figure.u.10"></div><pre class="inline"><span id="rfc.iref.g.16"></span> <a href="#obsolete.date.formats" class="smpl">obs-date</a> = <a href="#obsolete.date.formats" class="smpl">rfc850-date</a> / <a href="#obsolete.date.formats" class="smpl">asctime-date</a> … … 2253 2252 <a href="#obsolete.date.formats" class="smpl">date3</a> = <a href="#preferred.date.format" class="smpl">month</a> <a href="#imported.abnf" class="smpl">SP</a> ( 2<a href="#imported.abnf" class="smpl">DIGIT</a> / ( <a href="#imported.abnf" class="smpl">SP</a> 1<a href="#imported.abnf" class="smpl">DIGIT</a> )) 2254 2253 ; month day (e.g., Jun 2) 2255 </pre><div class="note" id="rfc.section. 7.1.p.15">2254 </pre><div class="note" id="rfc.section.8.1.p.15"> 2256 2255 <p> <b>Note:</b> Recipients of date values are encouraged to be robust in accepting date values that might have been sent by non-HTTP applications, 2257 2256 as is sometimes the case when retrieving or posting messages via proxies/gateways to SMTP or NNTP. 2258 2257 </p> 2259 2258 </div> 2260 <div class="note" id="rfc.section. 7.1.p.16">2259 <div class="note" id="rfc.section.8.1.p.16"> 2261 2260 <p> <b>Note:</b> HTTP requirements for the date/time stamp format apply only to their usage within the protocol stream. Clients and servers 2262 2261 are not required to use these formats for user presentation, request logging, etc. 2263 2262 </p> 2264 2263 </div> 2265 <h2 id="rfc.section. 7.2"><a href="#rfc.section.7.2">7.2</a> <a id="product.tokens" href="#product.tokens">Product Tokens</a></h2>2266 <p id="rfc.section. 7.2.p.1">Product tokens are used to allow communicating applications to identify themselves by software name and version. Most fields2264 <h2 id="rfc.section.8.2"><a href="#rfc.section.8.2">8.2</a> <a id="product.tokens" href="#product.tokens">Product Tokens</a></h2> 2265 <p id="rfc.section.8.2.p.1">Product tokens are used to allow communicating applications to identify themselves by software name and version. Most fields 2267 2266 using product tokens also allow sub-products which form a significant part of the application to be listed, separated by whitespace. 2268 2267 By convention, the products are listed in order of their significance for identifying the application. … … 2270 2269 <div id="rfc.figure.u.13"></div><pre class="inline"><span id="rfc.iref.g.19"></span><span id="rfc.iref.g.20"></span> <a href="#product.tokens" class="smpl">product</a> = <a href="#imported.abnf" class="smpl">token</a> ["/" <a href="#product.tokens" class="smpl">product-version</a>] 2271 2270 <a href="#product.tokens" class="smpl">product-version</a> = <a href="#imported.abnf" class="smpl">token</a> 2272 </pre><p id="rfc.section. 7.2.p.3">Examples:</p>2271 </pre><p id="rfc.section.8.2.p.3">Examples:</p> 2273 2272 <div id="rfc.figure.u.14"></div><pre class="text"> User-Agent: CERN-LineMode/2.15 libwww/2.17b3 2274 2273 Server: Apache/0.8.4 2275 </pre><p id="rfc.section. 7.2.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).2276 </p> 2277 <h2 id="rfc.section. 7.3"><a href="#rfc.section.7.3">7.3</a> <a id="character.sets" href="#character.sets">Character Encodings (charset)</a></h2>2278 <p id="rfc.section. 7.3.p.1">HTTP uses charset names to indicate the character encoding of a textual representation.</p>2274 </pre><p id="rfc.section.8.2.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). 2275 </p> 2276 <h2 id="rfc.section.8.3"><a href="#rfc.section.8.3">8.3</a> <a id="character.sets" href="#character.sets">Character Encodings (charset)</a></h2> 2277 <p id="rfc.section.8.3.p.1">HTTP uses charset names to indicate the character encoding of a textual representation.</p> 2279 2278 <div id="rule.charset"> 2280 <p id="rfc.section. 7.3.p.2"> A character encoding is identified by a case-insensitive token. The complete set of tokens is defined by the IANA Character2279 <p id="rfc.section.8.3.p.2"> A character encoding is identified by a case-insensitive token. The complete set of tokens is defined by the IANA Character 2281 2280 Set registry (<<a href="http://www.iana.org/assignments/character-sets">http://www.iana.org/assignments/character-sets</a>>). 2282 2281 </p> 2283 2282 </div> 2284 2283 <div id="rfc.figure.u.15"></div><pre class="inline"><span id="rfc.iref.g.21"></span> <a href="#rule.charset" class="smpl">charset</a> = <a href="#imported.abnf" class="smpl">token</a> 2285 </pre><p id="rfc.section. 7.3.p.4">Although HTTP allows an arbitrary token to be used as a charset value, any token that has a predefined value within the IANA2284 </pre><p id="rfc.section.8.3.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 2286 2285 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. 2287 2286 </p> 2288 <p id="rfc.section. 7.3.p.5">HTTP uses charset in two contexts: within an <a href="#header.accept-charset" class="smpl">Accept-Charset</a> request header field (in which the charset value is an unquoted token) and as the value of a parameter in a <a href="#header.content-type" class="smpl">Content-Type</a> header field (within a request or response), in which case the parameter value of the charset parameter can be quoted.2289 </p> 2290 <p id="rfc.section. 7.3.p.6">Implementers 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>.2291 </p> 2292 <h2 id="rfc.section. 7.4"><a href="#rfc.section.7.4">7.4</a> <a id="content.codings" href="#content.codings">Content Codings</a></h2>2293 <p id="rfc.section. 7.4.p.1">Content coding values indicate an encoding transformation that has been or can be applied to a representation. Content codings2287 <p id="rfc.section.8.3.p.5">HTTP uses charset in two contexts: within an <a href="#header.accept-charset" class="smpl">Accept-Charset</a> request header field (in which the charset value is an unquoted token) and as the value of a parameter in a <a href="#header.content-type" class="smpl">Content-Type</a> header field (within a request or response), in which case the parameter value of the charset parameter can be quoted. 2288 </p> 2289 <p id="rfc.section.8.3.p.6">Implementers 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>. 2290 </p> 2291 <h2 id="rfc.section.8.4"><a href="#rfc.section.8.4">8.4</a> <a id="content.codings" href="#content.codings">Content Codings</a></h2> 2292 <p id="rfc.section.8.4.p.1">Content coding values indicate an encoding transformation that has been or can be applied to a representation. Content codings 2294 2293 are primarily used to allow a representation to be compressed or otherwise usefully transformed without losing the identity 2295 2294 of its underlying media type and without loss of information. Frequently, the representation is stored in coded form, transmitted … … 2297 2296 </p> 2298 2297 <div id="rfc.figure.u.16"></div><pre class="inline"><span id="rfc.iref.g.22"></span> <a href="#content.codings" class="smpl">content-coding</a> = <a href="#imported.abnf" class="smpl">token</a> 2299 </pre><p id="rfc.section. 7.4.p.3">All content-coding values are case-insensitive. HTTP/1.1 uses content-coding values in the <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.2" title="Accept-Encoding">Section 10.3</a>) and <a href="#header.content-encoding" class="smpl">Content-Encoding</a> (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.2" title="Content-Encoding">Section 10.6</a>) header fields. Although the value describes the content-coding, what is more important is that it indicates what decoding2298 </pre><p id="rfc.section.8.4.p.3">All content-coding values are case-insensitive. HTTP/1.1 uses content-coding values in the <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.2" title="Accept-Encoding">Section 11.3</a>) and <a href="#header.content-encoding" class="smpl">Content-Encoding</a> (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.2" title="Content-Encoding">Section 11.6</a>) header fields. Although the value describes the content-coding, what is more important is that it indicates what decoding 2300 2299 mechanism will be required to remove the encoding. 2301 2300 </p> 2302 <p id="rfc.section. 7.4.p.4">compress<span id="rfc.iref.c.4"></span><span id="rfc.iref.c.5"></span>2301 <p id="rfc.section.8.4.p.4">compress<span id="rfc.iref.c.4"></span><span id="rfc.iref.c.5"></span> 2303 2302 </p> 2304 2303 <ul class="empty"> … … 2306 2305 </li> 2307 2306 </ul> 2308 <p id="rfc.section. 7.4.p.5">deflate<span id="rfc.iref.d.2"></span><span id="rfc.iref.c.6"></span>2307 <p id="rfc.section.8.4.p.5">deflate<span id="rfc.iref.d.2"></span><span id="rfc.iref.c.6"></span> 2309 2308 </p> 2310 2309 <ul class="empty"> … … 2312 2311 </li> 2313 2312 </ul> 2314 <p id="rfc.section. 7.4.p.6">gzip<span id="rfc.iref.g.23"></span><span id="rfc.iref.c.7"></span>2313 <p id="rfc.section.8.4.p.6">gzip<span id="rfc.iref.g.23"></span><span id="rfc.iref.c.7"></span> 2315 2314 </p> 2316 2315 <ul class="empty"> … … 2318 2317 </li> 2319 2318 </ul> 2320 <h2 id="rfc.section. 7.5"><a href="#rfc.section.7.5">7.5</a> <a id="media.types" href="#media.types">Media Types</a></h2>2321 <p id="rfc.section. 7.5.p.1">HTTP uses Internet Media Types <a href="#RFC2046" id="rfc.xref.RFC2046.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> in the <a href="#header.content-type" class="smpl">Content-Type</a> (<a href="#header.content-type" id="rfc.xref.header.content-type.3" title="Content-Type">Section 10.9</a>) and <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.2" title="Accept">Section 10.1</a>) header fields in order to provide open and extensible data typing and type negotiation.2319 <h2 id="rfc.section.8.5"><a href="#rfc.section.8.5">8.5</a> <a id="media.types" href="#media.types">Media Types</a></h2> 2320 <p id="rfc.section.8.5.p.1">HTTP uses Internet Media Types <a href="#RFC2046" id="rfc.xref.RFC2046.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> in the <a href="#header.content-type" class="smpl">Content-Type</a> (<a href="#header.content-type" id="rfc.xref.header.content-type.3" title="Content-Type">Section 11.9</a>) and <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.2" title="Accept">Section 11.1</a>) header fields in order to provide open and extensible data typing and type negotiation. 2322 2321 </p> 2323 2322 <div id="rfc.figure.u.17"></div><pre class="inline"><span id="rfc.iref.g.24"></span><span id="rfc.iref.g.25"></span><span id="rfc.iref.g.26"></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="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> ) … … 2325 2324 <a href="#media.types" class="smpl">subtype</a> = <a href="#imported.abnf" class="smpl">token</a> 2326 2325 </pre><div id="rule.parameter"> 2327 <p id="rfc.section. 7.5.p.3"> The type/subtype <em class="bcp14">MAY</em> be followed by parameters in the form of attribute/value pairs.2326 <p id="rfc.section.8.5.p.3"> The type/subtype <em class="bcp14">MAY</em> be followed by parameters in the form of attribute/value pairs. 2328 2327 </p> 2329 2328 </div> … … 2331 2330 <a href="#rule.parameter" class="smpl">attribute</a> = <a href="#imported.abnf" class="smpl">token</a> 2332 2331 <a href="#rule.parameter" class="smpl">value</a> = <a href="#imported.abnf" class="smpl">word</a> 2333 </pre><p id="rfc.section. 7.5.p.5">The type, subtype, and parameter attribute names are case-insensitive. Parameter values might or might not be case-sensitive,2332 </pre><p id="rfc.section.8.5.p.5">The type, subtype, and parameter attribute names are case-insensitive. Parameter values might or might not be case-sensitive, 2334 2333 depending on the semantics of the parameter name. The presence or absence of a parameter might be significant to the processing 2335 2334 of a media-type, depending on its definition within the media type registry. 2336 2335 </p> 2337 <p id="rfc.section. 7.5.p.6">A parameter value that matches the <a href="#imported.abnf" class="smpl">token</a> production can be transmitted as either a token or within a quoted-string. The quoted and unquoted values are equivalent.2338 </p> 2339 <p id="rfc.section. 7.5.p.7">Note that some older HTTP applications do not recognize media type parameters. When sending data to older HTTP applications,2336 <p id="rfc.section.8.5.p.6">A parameter value that matches the <a href="#imported.abnf" class="smpl">token</a> production can be transmitted as either a token or within a quoted-string. The quoted and unquoted values are equivalent. 2337 </p> 2338 <p id="rfc.section.8.5.p.7">Note that some older HTTP applications do not recognize media type parameters. When sending data to older HTTP applications, 2340 2339 implementations <em class="bcp14">SHOULD</em> only use media type parameters when they are required by that type/subtype definition. 2341 2340 </p> 2342 <p id="rfc.section. 7.5.p.8">Media-type values are registered with the Internet Assigned Number Authority (IANA). The media type registration process is2341 <p id="rfc.section.8.5.p.8">Media-type values are registered with the Internet Assigned Number Authority (IANA). The media type registration process is 2343 2342 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. 2344 2343 </p> 2345 <h3 id="rfc.section. 7.5.1"><a href="#rfc.section.7.5.1">7.5.1</a> <a id="canonicalization.and.text.defaults" href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></h3>2346 <p id="rfc.section. 7.5.1.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.2347 </p> 2348 <p id="rfc.section. 7.5.1.p.2">When in canonical form, media subtypes of the "text" type use CRLF as the text line break. HTTP relaxes this requirement and2344 <h3 id="rfc.section.8.5.1"><a href="#rfc.section.8.5.1">8.5.1</a> <a id="canonicalization.and.text.defaults" href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></h3> 2345 <p id="rfc.section.8.5.1.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. 2346 </p> 2347 <p id="rfc.section.8.5.1.p.2">When in canonical form, media subtypes of the "text" type use CRLF as the text line break. HTTP relaxes this requirement and 2349 2348 allows the transport of text media with plain CR or LF alone representing a line break when it is done consistently for an 2350 2349 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 … … 2354 2353 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). 2355 2354 </p> 2356 <p id="rfc.section. 7.5.1.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.2357 </p> 2358 <h3 id="rfc.section. 7.5.2"><a href="#rfc.section.7.5.2">7.5.2</a> <a id="multipart.types" href="#multipart.types">Multipart Types</a></h3>2359 <p id="rfc.section. 7.5.2.p.1">MIME provides for a number of "multipart" types — encapsulations of one or more representations within a single message body.2355 <p id="rfc.section.8.5.1.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. 2356 </p> 2357 <h3 id="rfc.section.8.5.2"><a href="#rfc.section.8.5.2">8.5.2</a> <a id="multipart.types" href="#multipart.types">Multipart Types</a></h3> 2358 <p id="rfc.section.8.5.2.p.1">MIME provides for a number of "multipart" types — encapsulations of one or more representations within a single message body. 2360 2359 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.RFC2046.3"><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. 2361 2360 </p> 2362 <p id="rfc.section. 7.5.2.p.2">In general, HTTP treats a multipart message body no differently than any other media type: strictly as payload. HTTP does2361 <p id="rfc.section.8.5.2.p.2">In general, HTTP treats a multipart message body no differently than any other media type: strictly as payload. HTTP does 2363 2362 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 2364 2363 each body-part of a multipart message body do not have any significance to HTTP beyond that defined by their MIME semantics. 2365 2364 </p> 2366 <p id="rfc.section. 7.5.2.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".2367 </p> 2368 <div class="note" id="rfc.section. 7.5.2.p.4">2365 <p id="rfc.section.8.5.2.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". 2366 </p> 2367 <div class="note" id="rfc.section.8.5.2.p.4"> 2369 2368 <p> <b>Note:</b> The "multipart/form-data" type has been specifically defined for carrying form data suitable for processing via the POST request 2370 2369 method, as described in <a href="#RFC2388" id="rfc.xref.RFC2388.1"><cite title="Returning Values from Forms: multipart/form-data">[RFC2388]</cite></a>. 2371 2370 </p> 2372 2371 </div> 2373 <h2 id="rfc.section. 7.6"><a href="#rfc.section.7.6">7.6</a> <a id="language.tags" href="#language.tags">Language Tags</a></h2>2374 <p id="rfc.section. 7.6.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 to2372 <h2 id="rfc.section.8.6"><a href="#rfc.section.8.6">8.6</a> <a id="language.tags" href="#language.tags">Language Tags</a></h2> 2373 <p id="rfc.section.8.6.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 2375 2374 other human beings. Computer languages are explicitly excluded. HTTP uses language tags within the <a href="#header.accept-language" class="smpl">Accept-Language</a> and <a href="#header.content-language" class="smpl">Content-Language</a> fields. 2376 2375 </p> 2377 <p id="rfc.section. 7.6.p.2">In summary, a language tag is composed of one or more parts: A primary language subtag followed by a possibly empty series2376 <p id="rfc.section.8.6.p.2">In summary, a language tag is composed of one or more parts: A primary language subtag followed by a possibly empty series 2378 2377 of subtags: 2379 2378 </p> 2380 2379 <div id="rfc.figure.u.19"></div><pre class="inline"><span id="rfc.iref.g.30"></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>> 2381 </pre><p id="rfc.section. 7.6.p.4">White space is not allowed within the tag and all tags are case-insensitive. The name space of language subtags is administered2380 </pre><p id="rfc.section.8.6.p.4">White space is not allowed within the tag and all tags are case-insensitive. The name space of language subtags is administered 2382 2381 by the IANA (see <<a href="http://www.iana.org/assignments/language-subtag-registry">http://www.iana.org/assignments/language-subtag-registry</a>>). 2383 2382 </p> 2384 2383 <div id="rfc.figure.u.20"></div> 2385 2384 <p>Example tags include:</p> <pre class="text"> en, en-US, es-419, az-Arab, x-pig-latin, man-Nkoo-GN 2386 </pre> <p id="rfc.section. 7.6.p.6">See <a href="#RFC5646" id="rfc.xref.RFC5646.3"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a> for further information.2387 </p> 2388 <h1 id="rfc.section. 8"><a href="#rfc.section.8">8.</a> <a id="payload" href="#payload">Payload</a></h1>2389 <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,2385 </pre> <p id="rfc.section.8.6.p.6">See <a href="#RFC5646" id="rfc.xref.RFC5646.3"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a> for further information. 2386 </p> 2387 <h1 id="rfc.section.9"><a href="#rfc.section.9">9.</a> <a id="payload" href="#payload">Payload</a></h1> 2388 <p id="rfc.section.9.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, 2390 2389 in the form of header fields, and data, in the form of the sequence of octets in the message body after any transfer-coding 2391 2390 has been decoded. 2392 2391 </p> 2393 2392 <div id="rfc.iref.p.3"></div> 2394 <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 representation2393 <p id="rfc.section.9.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 2395 2394 because some messages contain only the associated representation's header fields (e.g., responses to HEAD) or only some part(s) 2396 2395 of the representation (e.g., the <a href="p5-range.html#status.206" class="smpl">206 (Partial Content)</a> status code). 2397 2396 </p> 2398 <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>2399 <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 "payload2397 <h2 id="rfc.section.9.1"><a href="#rfc.section.9.1">9.1</a> <a id="payload.header.fields" href="#payload.header.fields">Payload Header Fields</a></h2> 2398 <p id="rfc.section.9.1.p.1">HTTP header fields that specifically define the payload, rather than the associated representation, are referred to as "payload 2400 2399 header fields". The following payload header fields are defined by HTTP/1.1: 2401 2400 </p> … … 2420 2419 </table> 2421 2420 </div> 2422 <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>2423 <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.Part1.26"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>. The payload body is obtained from the message body by decoding any <a href="p1-messaging.html#header.transfer-encoding" class="smpl">Transfer-Encoding</a> that might have been applied to ensure safe and proper transfer of the message.2424 </p> 2425 <h1 id="rfc.section. 9"><a href="#rfc.section.9">9.</a> <a id="content.negotiation" href="#content.negotiation">Content Negotiation</a></h1>2426 <p id="rfc.section. 9.p.1">HTTP responses include a representation which contains information for interpretation, whether by a human user or for further2421 <h2 id="rfc.section.9.2"><a href="#rfc.section.9.2">9.2</a> <a id="payload.body" href="#payload.body">Payload Body</a></h2> 2422 <p id="rfc.section.9.2.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.Part1.26"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>. The payload body is obtained from the message body by decoding any <a href="p1-messaging.html#header.transfer-encoding" class="smpl">Transfer-Encoding</a> that might have been applied to ensure safe and proper transfer of the message. 2423 </p> 2424 <h1 id="rfc.section.10"><a href="#rfc.section.10">10.</a> <a id="content.negotiation" href="#content.negotiation">Content Negotiation</a></h1> 2425 <p id="rfc.section.10.p.1">HTTP responses include a representation which contains information for interpretation, whether by a human user or for further 2427 2426 processing. Often, the server has different ways of representing the same information; for example, in different formats, 2428 2427 languages, or using different character encodings. 2429 2428 </p> 2430 <p id="rfc.section. 9.p.2">HTTP clients and their users might have different or variable capabilities, characteristics or preferences which would influence2429 <p id="rfc.section.10.p.2">HTTP clients and their users might have different or variable capabilities, characteristics or preferences which would influence 2431 2430 which representation, among those available from the server, would be best for the server to deliver. For this reason, HTTP 2432 2431 provides mechanisms for "content negotiation" — a process of allowing selection of a representation of a given resource, when 2433 2432 more than one is available. 2434 2433 </p> 2435 <p id="rfc.section. 9.p.3">This specification defines two patterns of content negotiation; "server-driven", where the server selects the representation2434 <p id="rfc.section.10.p.3">This specification defines two patterns of content negotiation; "server-driven", where the server selects the representation 2436 2435 based upon the client's stated preferences, and "agent-driven" negotiation, where the server provides a list of representations 2437 2436 for the client to choose from, based upon their metadata. In addition, there are other patterns: some applications use an … … 2439 2438 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. 2440 2439 </p> 2441 <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 number2440 <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 number 2442 2441 of preferences or capabilities to be expressed by a client are large (such as when many different formats are supported by 2443 2442 a user-agent), server-driven negotiation becomes unwieldy, and might not be appropriate. Conversely, when the number of representations 2444 2443 to choose from is very large, agent-driven negotiation might not be appropriate. 2445 2444 </p> 2446 <p id="rfc.section. 9.p.5">Note that, in all cases, the supplier of representations has the responsibility for determining which representations might2445 <p id="rfc.section.10.p.5">Note that, in all cases, the supplier of representations has the responsibility for determining which representations might 2447 2446 be considered to be the "same information". 2448 2447 </p> 2449 <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>2450 <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-driven2448 <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> 2449 <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-driven 2451 2450 negotiation. Selection is based on the available representations of the response (the dimensions over which it can vary; e.g., 2452 2451 language, content-coding, etc.) and the contents of particular header fields in the request message or on other information 2453 2452 pertaining to the request (such as the network address of the client). 2454 2453 </p> 2455 <p id="rfc.section. 9.1.p.2">Server-driven negotiation is advantageous when the algorithm for selecting from among the available representations is difficult2454 <p id="rfc.section.10.1.p.2">Server-driven negotiation is advantageous when the algorithm for selecting from among the available representations is difficult 2456 2455 to describe to the user agent, or when the server desires to send its "best guess" to the client along with the first response 2457 2456 (hoping to avoid the round-trip delay of a subsequent request if the "best guess" is good enough for the user). In order to 2458 2457 improve the server's guess, the user agent <em class="bcp14">MAY</em> include request header fields (<a href="#header.accept" class="smpl">Accept</a>, <a href="#header.accept-language" class="smpl">Accept-Language</a>, <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a>, etc.) which describe its preferences for such a response. 2459 2458 </p> 2460 <p id="rfc.section. 9.1.p.3">Server-driven negotiation has disadvantages: </p>2459 <p id="rfc.section.10.1.p.3">Server-driven negotiation has disadvantages: </p> 2461 2460 <ol> 2462 2461 <li>It is impossible for the server to accurately determine what might be "best" for any given user, since that would require … … 2470 2469 <li>It might limit a public cache's ability to use the same response for multiple user's requests.</li> 2471 2470 </ol> 2472 <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 honor2471 <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 honor 2473 2472 them. For example, the origin server might not implement server-driven negotiation, or it might decide that sending a response 2474 2473 that doesn't conform to them is better than sending a <a href="#status.406" class="smpl">406 2475 2474 (Not Acceptable)</a> response. 2476 2475 </p> 2477 <p id="rfc.section. 9.1.p.5">HTTP/1.1 includes the following header fields for enabling server-driven negotiation through description of user agent capabilities2478 and user preferences: <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.3" title="Accept">Section 1 0.1</a>), <a href="#header.accept-charset" class="smpl">Accept-Charset</a> (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.2" title="Accept-Charset">Section 10.2</a>), <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.3" title="Accept-Encoding">Section 10.3</a>), <a href="#header.accept-language" class="smpl">Accept-Language</a> (<a href="#header.accept-language" id="rfc.xref.header.accept-language.2" title="Accept-Language">Section 10.4</a>), and <a href="#header.user-agent" class="smpl">User-Agent</a> (<a href="#header.user-agent" id="rfc.xref.header.user-agent.2" title="User-Agent">Section 10.18</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 information2476 <p id="rfc.section.10.1.p.5">HTTP/1.1 includes the following header fields for enabling server-driven negotiation through description of user agent capabilities 2477 and user preferences: <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.3" title="Accept">Section 11.1</a>), <a href="#header.accept-charset" class="smpl">Accept-Charset</a> (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.2" title="Accept-Charset">Section 11.2</a>), <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.3" title="Accept-Encoding">Section 11.3</a>), <a href="#header.accept-language" class="smpl">Accept-Language</a> (<a href="#header.accept-language" id="rfc.xref.header.accept-language.2" title="Accept-Language">Section 11.4</a>), and <a href="#header.user-agent" class="smpl">User-Agent</a> (<a href="#header.user-agent" id="rfc.xref.header.user-agent.2" title="User-Agent">Section 11.18</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 2479 2478 within extension header fields not defined by this specification. 2480 2479 </p> 2481 <div class="note" id="rfc.section. 9.1.p.6">2480 <div class="note" id="rfc.section.10.1.p.6"> 2482 2481 <p> <b>Note:</b> In practice, <a href="#header.user-agent" class="smpl">User-Agent</a> based negotiation is fragile, because new clients might not be recognized. 2483 2482 </p> 2484 2483 </div> 2485 <p id="rfc.section. 9.1.p.7">The <a href="p6-cache.html#header.vary" class="smpl">Vary</a> header field (<a href="p6-cache.html#header.vary" title="Vary">Section 7.5</a> of <a href="#Part6" id="rfc.xref.Part6.17"><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.2486 </p> 2487 <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>2488 <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 receiving2484 <p id="rfc.section.10.1.p.7">The <a href="p6-cache.html#header.vary" class="smpl">Vary</a> header field (<a href="p6-cache.html#header.vary" title="Vary">Section 7.5</a> of <a href="#Part6" id="rfc.xref.Part6.17"><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. 2485 </p> 2486 <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> 2487 <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 receiving 2489 2488 an initial response from the origin server. Selection is based on a list of the available representations of the response 2490 2489 included within the header fields or body of the initial response, with each representation identified by its own URI. Selection … … 2492 2491 user selecting from a generated (possibly hypertext) menu. 2493 2492 </p> 2494 <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,2493 <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, 2495 2494 or encoding), when the origin server is unable to determine a user agent's capabilities from examining the request, and generally 2496 2495 when public caches are used to distribute server load and reduce network usage. 2497 2496 </p> 2498 <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.2497 <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. 2499 2498 This second request is only efficient when caching is used. In addition, this specification does not define any mechanism 2500 2499 for supporting automatic selection, though it also does not prevent any such mechanism from being developed as an extension 2501 2500 and used within HTTP/1.1. 2502 2501 </p> 2503 <p id="rfc.section. 9.2.p.4">This specification defines the <a href="#status.300" class="smpl">300 (Multiple Choices)</a> and <a href="#status.406" class="smpl">406 (Not Acceptable)</a> status codes for enabling agent-driven negotiation when the server is unwilling or unable to provide a varying response using2502 <p id="rfc.section.10.2.p.4">This specification defines the <a href="#status.300" class="smpl">300 (Multiple Choices)</a> and <a href="#status.406" class="smpl">406 (Not Acceptable)</a> status codes for enabling agent-driven negotiation when the server is unwilling or unable to provide a varying response using 2504 2503 server-driven negotiation. 2505 2504 </p> 2506 <h2 id="rfc.section. 9.3"><a href="#rfc.section.9.3">9.3</a> <a id="quality.values" href="#quality.values">Quality Values</a></h2>2507 <p id="rfc.section. 9.3.p.1">Many of the request header fields for server-driven content negotiation use a common parameter, named "q", to assign a relative2505 <h2 id="rfc.section.10.3"><a href="#rfc.section.10.3">10.3</a> <a id="quality.values" href="#quality.values">Quality Values</a></h2> 2506 <p id="rfc.section.10.3.p.1">Many of the request header fields for server-driven content negotiation use a common parameter, named "q", to assign a relative 2508 2507 "weight" to the preference for that associated kind of content. This weight is referred to as a "quality value" (or "qvalue") 2509 2508 because the same parameter name is often used within server configurations to assign a weight to the relative quality of the 2510 2509 various representations that can be selected for a resource. 2511 2510 </p> 2512 <p id="rfc.section. 9.3.p.2">The weight is normalized to a real number in the range 0 through 1, where 0.001 is the least preferred and 1 is the most preferred;2511 <p id="rfc.section.10.3.p.2">The weight is normalized to a real number in the range 0 through 1, where 0.001 is the least preferred and 1 is the most preferred; 2513 2512 a value of 0 means "not acceptable". If no "q" parameter is present, the default weight is 1. 2514 2513 </p> … … 2516 2515 <a href="#quality.values" class="smpl">qvalue</a> = ( "0" [ "." 0*3<a href="#imported.abnf" class="smpl">DIGIT</a> ] ) 2517 2516 / ( "1" [ "." 0*3("0") ] ) 2518 </pre><p id="rfc.section. 9.3.p.4">A sender of qvalue <em class="bcp14">MUST NOT</em> generate more than three digits after the decimal point. User configuration of these values ought to be limited in the same2517 </pre><p id="rfc.section.10.3.p.4">A sender of qvalue <em class="bcp14">MUST NOT</em> generate more than three digits after the decimal point. User configuration of these values ought to be limited in the same 2519 2518 fashion. 2520 2519 </p> 2521 <h1 id="rfc.section.1 0"><a href="#rfc.section.10">10.</a> <a id="header.field.definitions" href="#header.field.definitions">Header Field Definitions</a></h1>2522 <p id="rfc.section.1 0.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to request and response semantics and to the2520 <h1 id="rfc.section.11"><a href="#rfc.section.11">11.</a> <a id="header.field.definitions" href="#header.field.definitions">Header Field Definitions</a></h1> 2521 <p id="rfc.section.11.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to request and response semantics and to the 2523 2522 payload of messages. 2524 2523 </p> 2525 2524 <div id="rfc.iref.a.1"></div> 2526 2525 <div id="rfc.iref.h.2"></div> 2527 <h2 id="rfc.section.1 0.1"><a href="#rfc.section.10.1">10.1</a> <a id="header.accept" href="#header.accept">Accept</a></h2>2528 <p id="rfc.section.1 0.1.p.1">The "Accept" header field can be used by user agents to specify response media types that are acceptable. Accept header fields2526 <h2 id="rfc.section.11.1"><a href="#rfc.section.11.1">11.1</a> <a id="header.accept" href="#header.accept">Accept</a></h2> 2527 <p id="rfc.section.11.1.p.1">The "Accept" header field can be used by user agents to specify response media types that are acceptable. Accept header fields 2529 2528 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 2530 2529 for an in-line image. … … 2538 2537 <a href="#header.accept" class="smpl">accept-params</a> = <a href="#quality.values" class="smpl">weight</a> *( <a href="#header.accept" class="smpl">accept-ext</a> ) 2539 2538 <a href="#header.accept" class="smpl">accept-ext</a> = <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#imported.abnf" class="smpl">token</a> [ "=" <a href="#imported.abnf" class="smpl">word</a> ] 2540 </pre><p id="rfc.section.1 0.1.p.3">The asterisk "*" character is used to group media types into ranges, with "*/*" indicating all media types and "type/*" indicating2539 </pre><p id="rfc.section.11.1.p.3">The asterisk "*" character is used to group media types into ranges, with "*/*" indicating all media types and "type/*" indicating 2541 2540 all subtypes of that type. The media-range <em class="bcp14">MAY</em> include media type parameters that are applicable to that range. 2542 2541 </p> 2543 <p id="rfc.section.1 0.1.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 weight, as defined in <a href="#quality.values" title="Quality Values">Section 9.3</a>. The first "q" parameter (if any) separates the media-range parameter(s) from the accept-params.2544 </p> 2545 <div class="note" id="rfc.section.1 0.1.p.5">2542 <p id="rfc.section.11.1.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 weight, as defined in <a href="#quality.values" title="Quality Values">Section 10.3</a>. The first "q" parameter (if any) separates the media-range parameter(s) from the accept-params. 2543 </p> 2544 <div class="note" id="rfc.section.11.1.p.5"> 2546 2545 <p> <b>Note:</b> Use of the "q" parameter name to separate media type parameters from Accept extension parameters is due to historical practice. 2547 2546 Although this prevents any media type parameter named "q" from being used with a media range, such an event is believed to … … 2550 2549 </p> 2551 2550 </div> 2552 <p id="rfc.section.1 0.1.p.6">The example</p>2551 <p id="rfc.section.11.1.p.6">The example</p> 2553 2552 <div id="rfc.figure.u.23"></div><pre class="text"> Accept: audio/*; q=0.2, audio/basic 2554 </pre><p id="rfc.section.1 0.1.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 in2553 </pre><p id="rfc.section.11.1.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 2555 2554 quality". 2556 2555 </p> 2557 <p id="rfc.section.1 0.1.p.9">A request without any Accept header field implies that the user agent will accept any media type in response. If an Accept2556 <p id="rfc.section.11.1.p.9">A request without any Accept header field implies that the user agent will accept any media type in response. If an Accept 2558 2557 header field is present in a request and none of the available representations for the response have a media type that is 2559 2558 listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept header field by sending a <a href="#status.406" class="smpl">406 (Not Acceptable)</a> response or disregard the Accept header field by treating the response as if it is not subject to content negotiation. 2560 2559 </p> 2561 <p id="rfc.section.1 0.1.p.10">A more elaborate example is</p>2560 <p id="rfc.section.11.1.p.10">A more elaborate example is</p> 2562 2561 <div id="rfc.figure.u.24"></div><pre class="text"> Accept: text/plain; q=0.5, text/html, 2563 2562 text/x-dvi; q=0.8, text/x-c 2564 </pre><p id="rfc.section.1 0.1.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, then2563 </pre><p id="rfc.section.11.1.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 2565 2564 send the text/x-dvi representation, and if that does not exist, send the text/plain representation". 2566 2565 </p> 2567 <p id="rfc.section.1 0.1.p.13">Media ranges can be overridden by more specific media ranges or specific media types. If more than one media range applies2566 <p id="rfc.section.11.1.p.13">Media ranges can be overridden by more specific media ranges or specific media types. If more than one media range applies 2568 2567 to a given type, the most specific reference has precedence. For example, 2569 2568 </p> 2570 2569 <div id="rfc.figure.u.25"></div><pre class="text"> Accept: text/*, text/plain, text/plain;format=flowed, */* 2571 </pre><p id="rfc.section.1 0.1.p.15">have the following precedence: </p>2570 </pre><p id="rfc.section.11.1.p.15">have the following precedence: </p> 2572 2571 <ol> 2573 2572 <li>text/plain;format=flowed</li> … … 2576 2575 <li>*/*</li> 2577 2576 </ol> 2578 <p id="rfc.section.1 0.1.p.16">The media type quality factor associated with a given type is determined by finding the media range with the highest precedence2577 <p id="rfc.section.11.1.p.16">The media type quality factor associated with a given type is determined by finding the media range with the highest precedence 2579 2578 which matches that type. For example, 2580 2579 </p> 2581 2580 <div id="rfc.figure.u.26"></div><pre class="text"> Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1, 2582 2581 text/html;level=2;q=0.4, */*;q=0.5 2583 </pre><p id="rfc.section.1 0.1.p.18">would cause the following values to be associated:</p>2582 </pre><p id="rfc.section.11.1.p.18">would cause the following values to be associated:</p> 2584 2583 <div id="rfc.table.u.7"> 2585 2584 <table class="tt full left" cellpadding="3" cellspacing="0"> … … 2618 2617 </table> 2619 2618 </div> 2620 <p id="rfc.section.1 0.1.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 agent2619 <p id="rfc.section.11.1.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 2621 2620 is a closed system which cannot interact with other rendering agents, this default set ought to be configurable by the user. 2622 2621 </p> 2623 2622 <div id="rfc.iref.a.2"></div> 2624 2623 <div id="rfc.iref.h.3"></div> 2625 <h2 id="rfc.section.1 0.2"><a href="#rfc.section.10.2">10.2</a> <a id="header.accept-charset" href="#header.accept-charset">Accept-Charset</a></h2>2626 <p id="rfc.section.1 0.2.p.1">The "Accept-Charset" header field can be used by user agents to indicate what character encodings are acceptable in a response2624 <h2 id="rfc.section.11.2"><a href="#rfc.section.11.2">11.2</a> <a id="header.accept-charset" href="#header.accept-charset">Accept-Charset</a></h2> 2625 <p id="rfc.section.11.2.p.1">The "Accept-Charset" header field can be used by user agents to indicate what character encodings are acceptable in a response 2627 2626 payload. This field allows clients capable of understanding more comprehensive or special-purpose character encodings to signal 2628 2627 that capability to a server which is capable of representing documents in those character encodings. 2629 2628 </p> 2630 2629 <div id="rfc.figure.u.27"></div><pre class="inline"><span id="rfc.iref.g.37"></span> <a href="#header.accept-charset" class="smpl">Accept-Charset</a> = 1#( ( <a href="#rule.charset" class="smpl">charset</a> / "*" ) [ <a href="#quality.values" class="smpl">weight</a> ] ) 2631 </pre><p id="rfc.section.1 0.2.p.3">Character encoding values (a.k.a., charsets) are described in <a href="#character.sets" title="Character Encodings (charset)">Section 7.3</a>. Each charset <em class="bcp14">MAY</em> be given an associated quality value which represents the user's preference for that charset, as defined in <a href="#quality.values" title="Quality Values">Section 9.3</a>. An example is2630 </pre><p id="rfc.section.11.2.p.3">Character encoding values (a.k.a., charsets) are described in <a href="#character.sets" title="Character Encodings (charset)">Section 8.3</a>. Each charset <em class="bcp14">MAY</em> be given an associated quality value which represents the user's preference for that charset, as defined in <a href="#quality.values" title="Quality Values">Section 10.3</a>. An example is 2632 2631 </p> 2633 2632 <div id="rfc.figure.u.28"></div><pre class="text"> Accept-Charset: iso-8859-5, unicode-1-1;q=0.8 2634 </pre><p id="rfc.section.1 0.2.p.5">The special value "*", if present in the Accept-Charset field, matches every character encoding which is not mentioned elsewhere2633 </pre><p id="rfc.section.11.2.p.5">The special value "*", if present in the Accept-Charset field, matches every character encoding which is not mentioned elsewhere 2635 2634 in the Accept-Charset field. If no "*" is present in an Accept-Charset field, then any character encodings not explicitly 2636 2635 mentioned in the field are considered "not acceptable" to the client. 2637 2636 </p> 2638 <p id="rfc.section.1 0.2.p.6">A request without any Accept-Charset header field implies that the user agent will accept any character encoding in response.</p>2639 <p id="rfc.section.1 0.2.p.7">If an Accept-Charset header field is present in a request and none of the available representations for the response have2637 <p id="rfc.section.11.2.p.6">A request without any Accept-Charset header field implies that the user agent will accept any character encoding in response.</p> 2638 <p id="rfc.section.11.2.p.7">If an Accept-Charset header field is present in a request and none of the available representations for the response have 2640 2639 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 <a href="#status.406" class="smpl">406 (Not Acceptable)</a> response or disregard the Accept-Charset header field by treating the response as if it is not subject to content negotiation. 2641 2640 </p> 2642 2641 <div id="rfc.iref.a.3"></div> 2643 2642 <div id="rfc.iref.h.4"></div> 2644 <h2 id="rfc.section.1 0.3"><a href="#rfc.section.10.3">10.3</a> <a id="header.accept-encoding" href="#header.accept-encoding">Accept-Encoding</a></h2>2645 <p id="rfc.section.1 0.3.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 7.4</a>) are acceptable in the response. An "identity" token is used as a synonym for "no encoding" in order to communicate when2643 <h2 id="rfc.section.11.3"><a href="#rfc.section.11.3">11.3</a> <a id="header.accept-encoding" href="#header.accept-encoding">Accept-Encoding</a></h2> 2644 <p id="rfc.section.11.3.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 8.4</a>) are acceptable in the response. An "identity" token is used as a synonym for "no encoding" in order to communicate when 2646 2645 no encoding is preferred. 2647 2646 </p> 2648 2647 <div id="rfc.figure.u.29"></div><pre class="inline"><span id="rfc.iref.g.38"></span><span id="rfc.iref.g.39"></span> <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> = #( <a href="#header.accept-encoding" class="smpl">codings</a> [ <a href="#quality.values" class="smpl">weight</a> ] ) 2649 2648 <a href="#header.accept-encoding" class="smpl">codings</a> = <a href="#content.codings" class="smpl">content-coding</a> / "identity" / "*" 2650 </pre><p id="rfc.section.1 0.3.p.3">Each codings value <em class="bcp14">MAY</em> be given an associated quality value which represents the preference for that encoding, as defined in <a href="#quality.values" title="Quality Values">Section 9.3</a>.2651 </p> 2652 <p id="rfc.section.1 0.3.p.4">For example,</p>2649 </pre><p id="rfc.section.11.3.p.3">Each codings value <em class="bcp14">MAY</em> be given an associated quality value which represents the preference for that encoding, as defined in <a href="#quality.values" title="Quality Values">Section 10.3</a>. 2650 </p> 2651 <p id="rfc.section.11.3.p.4">For example,</p> 2653 2652 <div id="rfc.figure.u.30"></div><pre class="text"> Accept-Encoding: compress, gzip 2654 2653 Accept-Encoding: … … 2656 2655 Accept-Encoding: compress;q=0.5, gzip;q=1.0 2657 2656 Accept-Encoding: gzip;q=1.0, identity; q=0.5, *;q=0 2658 </pre><p id="rfc.section.1 0.3.p.6">A server tests whether a content-coding for a given representation is acceptable, according to an Accept-Encoding field, using2657 </pre><p id="rfc.section.11.3.p.6">A server tests whether a content-coding for a given representation is acceptable, according to an Accept-Encoding field, using 2659 2658 these rules: 2660 2659 </p> … … 2667 2666 </li> 2668 2667 <li>If the representation's content-coding is one of the content-codings listed in the Accept-Encoding field, then it is acceptable 2669 unless it is accompanied by a qvalue of 0. (As defined in <a href="#quality.values" title="Quality Values">Section 9.3</a>, a qvalue of 0 means "not acceptable".)2668 unless it is accompanied by a qvalue of 0. (As defined in <a href="#quality.values" title="Quality Values">Section 10.3</a>, a qvalue of 0 means "not acceptable".) 2670 2669 </li> 2671 2670 <li>If multiple content-codings are acceptable, then the acceptable content-coding with the highest non-zero qvalue is preferred.</li> 2672 2671 </ol> 2673 <p id="rfc.section.1 0.3.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-coding2672 <p id="rfc.section.11.3.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 2674 2673 in response. If an Accept-Encoding header field is present in a request and none of the available representations for the 2675 2674 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. 2676 2675 </p> 2677 <p id="rfc.section.1 0.3.p.8">A request without an Accept-Encoding header field implies that the user agent will accept any content-coding in response.</p>2678 <div class="note" id="rfc.section.1 0.3.p.9">2676 <p id="rfc.section.11.3.p.8">A request without an Accept-Encoding header field implies that the user agent will accept any content-coding in response.</p> 2677 <div class="note" id="rfc.section.11.3.p.9"> 2679 2678 <p> <b>Note:</b> Most HTTP/1.0 applications do not recognize or obey qvalues associated with content-codings. This means that qvalues will 2680 2679 not work and are not permitted with x-gzip or x-compress. … … 2683 2682 <div id="rfc.iref.a.4"></div> 2684 2683 <div id="rfc.iref.h.5"></div> 2685 <h2 id="rfc.section.1 0.4"><a href="#rfc.section.10.4">10.4</a> <a id="header.accept-language" href="#header.accept-language">Accept-Language</a></h2>2686 <p id="rfc.section.1 0.4.p.1">The "Accept-Language" header field can be used by user agents to indicate the set of natural languages that are preferred2687 in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section 7.6</a>.2684 <h2 id="rfc.section.11.4"><a href="#rfc.section.11.4">11.4</a> <a id="header.accept-language" href="#header.accept-language">Accept-Language</a></h2> 2685 <p id="rfc.section.11.4.p.1">The "Accept-Language" header field can be used by user agents to indicate the set of natural languages that are preferred 2686 in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section 8.6</a>. 2688 2687 </p> 2689 2688 <div id="rfc.figure.u.31"></div><pre class="inline"><span id="rfc.iref.g.40"></span><span id="rfc.iref.g.41"></span> <a href="#header.accept-language" class="smpl">Accept-Language</a> = 1#( <a href="#header.accept-language" class="smpl">language-range</a> [ <a href="#quality.values" class="smpl">weight</a> ] ) 2690 2689 <a href="#header.accept-language" class="smpl">language-range</a> = 2691 2690 <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>> 2692 </pre><p id="rfc.section.1 0.4.p.3">Each language-range can be given an associated quality value which represents an estimate of the user's preference for the2693 languages specified by that range, as defined in <a href="#quality.values" title="Quality Values">Section 9.3</a>. For example,2691 </pre><p id="rfc.section.11.4.p.3">Each language-range can be given an associated quality value which represents an estimate of the user's preference for the 2692 languages specified by that range, as defined in <a href="#quality.values" title="Quality Values">Section 10.3</a>. For example, 2694 2693 </p> 2695 2694 <div id="rfc.figure.u.32"></div><pre class="text"> Accept-Language: da, en-gb;q=0.8, en;q=0.7 2696 </pre><p id="rfc.section.1 0.4.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>)2697 </p> 2698 <p id="rfc.section.1 0.4.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.2699 </p> 2700 <div class="note" id="rfc.section.1 0.4.p.7">2695 </pre><p id="rfc.section.11.4.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>) 2696 </p> 2697 <p id="rfc.section.11.4.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. 2698 </p> 2699 <div class="note" id="rfc.section.11.4.p.7"> 2701 2700 <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.RFC2616.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>. 2702 2701 </p> 2703 2702 </div> 2704 <p id="rfc.section.1 0.4.p.8">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic2705 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 2.5</a>.2706 </p> 2707 <p id="rfc.section.1 0.4.p.9">As intelligibility is highly dependent on the individual user, it is recommended that client applications make the choice2703 <p id="rfc.section.11.4.p.8">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic 2704 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 13.5</a>. 2705 </p> 2706 <p id="rfc.section.11.4.p.9">As intelligibility is highly dependent on the individual user, it is recommended that client applications make the choice 2708 2707 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. 2709 2708 </p> 2710 <div class="note" id="rfc.section.1 0.4.p.10">2709 <div class="note" id="rfc.section.11.4.p.10"> 2711 2710 <p> <b>Note:</b> When making the choice of linguistic preference available to the user, we remind implementers of the fact that users are not 2712 2711 familiar with the details of language matching as described above, and ought to be provided appropriate guidance. As an example, … … 2717 2716 <div id="rfc.iref.a.5"></div> 2718 2717 <div id="rfc.iref.h.6"></div> 2719 <h2 id="rfc.section.1 0.5"><a href="#rfc.section.10.5">10.5</a> <a id="header.allow" href="#header.allow">Allow</a></h2>2720 <p id="rfc.section.1 0.5.p.1">The "Allow" header field lists the set of methods advertised as supported by the target resource. The purpose of this field2718 <h2 id="rfc.section.11.5"><a href="#rfc.section.11.5">11.5</a> <a id="header.allow" href="#header.allow">Allow</a></h2> 2719 <p id="rfc.section.11.5.p.1">The "Allow" header field lists the set of methods advertised as supported by the target resource. The purpose of this field 2721 2720 is strictly to inform the recipient of valid request methods associated with the resource. 2722 2721 </p> 2723 2722 <div id="rfc.figure.u.33"></div><pre class="inline"><span id="rfc.iref.g.42"></span> <a href="#header.allow" class="smpl">Allow</a> = #<a href="#method.overview" class="smpl">method</a> 2724 </pre><p id="rfc.section.1 0.5.p.3">Example of use:</p>2723 </pre><p id="rfc.section.11.5.p.3">Example of use:</p> 2725 2724 <div id="rfc.figure.u.34"></div><pre class="text"> Allow: GET, HEAD, PUT 2726 </pre><p id="rfc.section.1 0.5.p.5">The actual set of allowed methods is defined by the origin server at the time of each request.</p>2727 <p id="rfc.section.1 0.5.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 according2725 </pre><p id="rfc.section.11.5.p.5">The actual set of allowed methods is defined by the origin server at the time of each request.</p> 2726 <p id="rfc.section.11.5.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 2728 2727 to the generic message handling rules. 2729 2728 </p> 2730 2729 <div id="rfc.iref.c.8"></div> 2731 2730 <div id="rfc.iref.h.7"></div> 2732 <h2 id="rfc.section.1 0.6"><a href="#rfc.section.10.6">10.6</a> <a id="header.content-encoding" href="#header.content-encoding">Content-Encoding</a></h2>2733 <p id="rfc.section.1 0.6.p.1">The "Content-Encoding" header field indicates what content-codings have been applied to the representation beyond those inherent2731 <h2 id="rfc.section.11.6"><a href="#rfc.section.11.6">11.6</a> <a id="header.content-encoding" href="#header.content-encoding">Content-Encoding</a></h2> 2732 <p id="rfc.section.11.6.p.1">The "Content-Encoding" header field indicates what content-codings have been applied to the representation beyond those inherent 2734 2733 in the media type, and thus what decoding mechanisms have to be applied in order to obtain the media-type referenced by the <a href="#header.content-type" class="smpl">Content-Type</a> header field. Content-Encoding is primarily used to allow a representation to be compressed without losing the identity of 2735 2734 its underlying media type. 2736 2735 </p> 2737 2736 <div id="rfc.figure.u.35"></div><pre class="inline"><span id="rfc.iref.g.43"></span> <a href="#header.content-encoding" class="smpl">Content-Encoding</a> = 1#<a href="#content.codings" class="smpl">content-coding</a> 2738 </pre><p id="rfc.section.1 0.6.p.3">Content codings are defined in <a href="#content.codings" title="Content Codings">Section 7.4</a>. An example of its use is2737 </pre><p id="rfc.section.11.6.p.3">Content codings are defined in <a href="#content.codings" title="Content Codings">Section 8.4</a>. An example of its use is 2739 2738 </p> 2740 2739 <div id="rfc.figure.u.36"></div><pre class="text"> Content-Encoding: gzip 2741 </pre><p id="rfc.section.1 0.6.p.5">The content-coding is a characteristic of the representation. Typically, the representation body is stored with this encoding2740 </pre><p id="rfc.section.11.6.p.5">The content-coding is a characteristic of the representation. Typically, the representation body is stored with this encoding 2742 2741 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 2743 2742 directive is present in the message. 2744 2743 </p> 2745 <p id="rfc.section.1 0.6.p.6">If the media type includes an inherent encoding, such as a data format that is always compressed, then that encoding would2744 <p id="rfc.section.11.6.p.6">If the media type includes an inherent encoding, such as a data format that is always compressed, then that encoding would 2746 2745 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 2747 2746 would only be listed if, for some bizarre reason, it is applied a second time to form the representation. Likewise, an origin … … 2750 2749 as ..." dialog instead of automatic decompression and rendering of content). 2751 2750 </p> 2752 <p id="rfc.section.1 0.6.p.7">A representation that has a content-coding applied to it <em class="bcp14">MUST</em> include a Content-Encoding header field that lists the content-coding(s) applied.2753 </p> 2754 <p id="rfc.section.1 0.6.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.2755 </p> 2756 <p id="rfc.section.1 0.6.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).2751 <p id="rfc.section.11.6.p.7">A representation that has a content-coding applied to it <em class="bcp14">MUST</em> include a Content-Encoding header field that lists the content-coding(s) applied. 2752 </p> 2753 <p id="rfc.section.11.6.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. 2754 </p> 2755 <p id="rfc.section.11.6.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). 2757 2756 </p> 2758 2757 <div id="rfc.iref.c.9"></div> 2759 2758 <div id="rfc.iref.h.8"></div> 2760 <h2 id="rfc.section.1 0.7"><a href="#rfc.section.10.7">10.7</a> <a id="header.content-language" href="#header.content-language">Content-Language</a></h2>2761 <p id="rfc.section.1 0.7.p.1">The "Content-Language" header field describes the natural language(s) of the intended audience for the representation. Note2759 <h2 id="rfc.section.11.7"><a href="#rfc.section.11.7">11.7</a> <a id="header.content-language" href="#header.content-language">Content-Language</a></h2> 2760 <p id="rfc.section.11.7.p.1">The "Content-Language" header field describes the natural language(s) of the intended audience for the representation. Note 2762 2761 that this might not be equivalent to all the languages used within the representation. 2763 2762 </p> 2764 2763 <div id="rfc.figure.u.37"></div><pre class="inline"><span id="rfc.iref.g.44"></span> <a href="#header.content-language" class="smpl">Content-Language</a> = 1#<a href="#language.tags" class="smpl">language-tag</a> 2765 </pre><p id="rfc.section.1 0.7.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section 7.6</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the2764 </pre><p id="rfc.section.11.7.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section 8.6</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the 2766 2765 user's own preferred language. Thus, if the body content is intended only for a Danish-literate audience, the appropriate 2767 2766 field is 2768 2767 </p> 2769 2768 <div id="rfc.figure.u.38"></div><pre class="text"> Content-Language: da 2770 </pre><p id="rfc.section.1 0.7.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean2769 </pre><p id="rfc.section.11.7.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean 2771 2770 that the sender does not consider it to be specific to any natural language, or that the sender does not know for which language 2772 2771 it is intended. 2773 2772 </p> 2774 <p id="rfc.section.1 0.7.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", presented2773 <p id="rfc.section.11.7.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 2775 2774 simultaneously in the original Maori and English versions, would call for 2776 2775 </p> 2777 2776 <div id="rfc.figure.u.39"></div><pre class="text"> Content-Language: mi, en 2778 </pre><p id="rfc.section.1 0.7.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple2777 </pre><p id="rfc.section.11.7.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple 2779 2778 linguistic audiences. An example would be a beginner's language primer, such as "A First Lesson in Latin", which is clearly 2780 2779 intended to be used by an English-literate audience. In this case, the Content-Language would properly only include "en". 2781 2780 </p> 2782 <p id="rfc.section.1 0.7.p.9">Content-Language <em class="bcp14">MAY</em> be applied to any media type — it is not limited to textual documents.2781 <p id="rfc.section.11.7.p.9">Content-Language <em class="bcp14">MAY</em> be applied to any media type — it is not limited to textual documents. 2783 2782 </p> 2784 2783 <div id="rfc.iref.c.10"></div> 2785 2784 <div id="rfc.iref.h.9"></div> 2786 <h2 id="rfc.section.1 0.8"><a href="#rfc.section.10.8">10.8</a> <a id="header.content-location" href="#header.content-location">Content-Location</a></h2>2787 <p id="rfc.section.1 0.8.p.1">The "Content-Location" header field supplies a URI that can be used as a specific identifier for the representation in this2785 <h2 id="rfc.section.11.8"><a href="#rfc.section.11.8">11.8</a> <a id="header.content-location" href="#header.content-location">Content-Location</a></h2> 2786 <p id="rfc.section.11.8.p.1">The "Content-Location" header field supplies a URI that can be used as a specific identifier for the representation in this 2788 2787 message. In other words, if one were to perform a GET on this URI at the time of this message's generation, then a <a href="#status.200" class="smpl">200 (OK)</a> response would contain the same representation that is enclosed as payload in this message. 2789 2788 </p> 2790 2789 <div id="rfc.figure.u.40"></div><pre class="inline"><span id="rfc.iref.g.45"></span> <a href="#header.content-location" class="smpl">Content-Location</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a> 2791 </pre><p id="rfc.section.1 0.8.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.Part1.27"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). It is representation metadata. It has the same syntax and semantics as the header field of the same name defined for MIME2790 </pre><p id="rfc.section.11.8.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.Part1.27"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[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 2792 2791 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. 2793 2792 </p> 2794 <p id="rfc.section.1 0.8.p.4">If Content-Location is included in a response message and its value is the same as the effective request URI, then the response2793 <p id="rfc.section.11.8.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 2795 2794 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 2796 2795 when no Content-Location is provided by the server. For a state-changing request like PUT or POST, it implies that the server's … … 2799 2798 need for a subsequent GET request. 2800 2799 </p> 2801 <p id="rfc.section.1 0.8.p.5">If Content-Location is included in a response message and its value differs from the effective request URI, then the origin2800 <p id="rfc.section.11.8.p.5">If Content-Location is included in a response message and its value differs from the effective request URI, then the origin 2802 2801 server is informing recipients that this representation has its own, presumably more specific, identifier. For a GET or HEAD 2803 2802 request, this is an indication that the effective request URI identifies a resource that is subject to content negotiation … … 2807 2806 the payload of the <a href="#status.200" class="smpl">200 (OK)</a> response; the Content-Location value provides an identifier for retrieving a copy of that same receipt in the future. 2808 2807 </p> 2809 <p id="rfc.section.1 0.8.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 enclosed2808 <p id="rfc.section.11.8.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 2810 2809 representation (prior to any subsequent modification of the content by that user agent). In other words, the user agent is 2811 2810 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 … … 2815 2814 latter semantics, it would have applied the PUT directly to the Content-Location URI. 2816 2815 </p> 2817 <p id="rfc.section.1 0.8.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 use2816 <p id="rfc.section.11.8.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 2818 2817 in other contexts, such as within source links or other metadata. 2819 2818 </p> 2820 <p id="rfc.section.1 0.8.p.8">A cache cannot assume that a representation with a Content-Location different from the URI used to retrieve it can be used2819 <p id="rfc.section.11.8.p.8">A cache cannot assume that a representation with a Content-Location different from the URI used to retrieve it can be used 2821 2820 to respond to later requests on that Content-Location URI. 2822 2821 </p> 2823 <p id="rfc.section.1 0.8.p.9">If the Content-Location value is a partial URI, the partial URI is interpreted relative to the effective request URI.</p>2822 <p id="rfc.section.11.8.p.9">If the Content-Location value is a partial URI, the partial URI is interpreted relative to the effective request URI.</p> 2824 2823 <div id="rfc.iref.c.11"></div> 2825 2824 <div id="rfc.iref.h.10"></div> 2826 <h2 id="rfc.section.1 0.9"><a href="#rfc.section.10.9">10.9</a> <a id="header.content-type" href="#header.content-type">Content-Type</a></h2>2827 <p id="rfc.section.1 0.9.p.1">The "Content-Type" header field indicates the media type of the representation. In the case of responses to the HEAD method,2825 <h2 id="rfc.section.11.9"><a href="#rfc.section.11.9">11.9</a> <a id="header.content-type" href="#header.content-type">Content-Type</a></h2> 2826 <p id="rfc.section.11.9.p.1">The "Content-Type" header field indicates the media type of the representation. In the case of responses to the HEAD method, 2828 2827 the media type is that which would have been sent had the request been a GET. 2829 2828 </p> 2830 2829 <div id="rfc.figure.u.41"></div><pre class="inline"><span id="rfc.iref.g.46"></span> <a href="#header.content-type" class="smpl">Content-Type</a> = <a href="#media.types" class="smpl">media-type</a> 2831 </pre><p id="rfc.section.1 0.9.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section 7.5</a>. An example of the field is2830 </pre><p id="rfc.section.11.9.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section 8.5</a>. An example of the field is 2832 2831 </p> 2833 2832 <div id="rfc.figure.u.42"></div><pre class="text"> Content-Type: text/html; charset=ISO-8859-4 2834 </pre><p id="rfc.section.1 0.9.p.5">Further discussion of Content-Type is provided in <a href="#representation.data" title="Representation Data">Section 3.3</a>.2833 </pre><p id="rfc.section.11.9.p.5">Further discussion of Content-Type is provided in <a href="#representation.data" title="Representation Data">Section 3.3</a>. 2835 2834 </p> 2836 2835 <div id="rfc.iref.d.3"></div> 2837 2836 <div id="rfc.iref.h.11"></div> 2838 <h2 id="rfc.section.1 0.10"><a href="#rfc.section.10.10">10.10</a> <a id="header.date" href="#header.date">Date</a></h2>2839 <p id="rfc.section.1 0.10.p.1">The "Date" header field represents the date and time at which the message was originated, having the same semantics as the2840 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 7.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format.2837 <h2 id="rfc.section.11.10"><a href="#rfc.section.11.10">11.10</a> <a id="header.date" href="#header.date">Date</a></h2> 2838 <p id="rfc.section.11.10.p.1">The "Date" header field represents the date and time at which the message was originated, having the same semantics as the 2839 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 8.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format. 2841 2840 </p> 2842 2841 <div id="rfc.figure.u.43"></div><pre class="inline"><span id="rfc.iref.g.47"></span> <a href="#header.date" class="smpl">Date</a> = <a href="#http.date" class="smpl">HTTP-date</a> 2843 </pre><p id="rfc.section.1 0.10.p.3">An example is</p>2842 </pre><p id="rfc.section.11.10.p.3">An example is</p> 2844 2843 <div id="rfc.figure.u.44"></div><pre class="text"> Date: Tue, 15 Nov 1994 08:12:31 GMT 2845 </pre><p id="rfc.section.1 0.10.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases:2844 </pre><p id="rfc.section.11.10.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases: 2846 2845 </p> 2847 2846 <ol> … … 2854 2853 </li> 2855 2854 </ol> 2856 <p id="rfc.section.1 0.10.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.2857 </p> 2858 <p id="rfc.section.1 0.10.p.7">Clients can use the Date header field as well; in order to keep request messages small, they are advised not to include it2855 <p id="rfc.section.11.10.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. 2856 </p> 2857 <p id="rfc.section.11.10.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 2859 2858 when it doesn't convey any useful information (as is usually the case for requests that do not contain a payload). 2860 2859 </p> 2861 <p id="rfc.section.1 0.10.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 means2860 <p id="rfc.section.11.10.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 2862 2861 of generating a reasonably accurate date and time. In theory, the date ought to represent the moment just before the payload 2863 2862 is generated. In practice, the date can be generated at any time during the message origination without affecting its semantic … … 2866 2865 <div id="rfc.iref.e.1"></div> 2867 2866 <div id="rfc.iref.h.12"></div> 2868 <h2 id="rfc.section.1 0.11"><a href="#rfc.section.10.11">10.11</a> <a id="header.expect" href="#header.expect">Expect</a></h2>2869 <p id="rfc.section.1 0.11.p.1">The "Expect" header field is used to indicate that particular server behaviors are required by the client.</p>2867 <h2 id="rfc.section.11.11"><a href="#rfc.section.11.11">11.11</a> <a id="header.expect" href="#header.expect">Expect</a></h2> 2868 <p id="rfc.section.11.11.p.1">The "Expect" header field is used to indicate that particular server behaviors are required by the client.</p> 2870 2869 <div id="rfc.figure.u.45"></div><pre class="inline"><span id="rfc.iref.g.48"></span><span id="rfc.iref.g.49"></span><span id="rfc.iref.g.50"></span><span id="rfc.iref.g.51"></span><span id="rfc.iref.g.52"></span> <a href="#header.expect" class="smpl">Expect</a> = 1#<a href="#header.expect" class="smpl">expectation</a> 2871 2870 … … 2876 2875 <a href="#header.expect" class="smpl">expect-name</a> = <a href="#imported.abnf" class="smpl">token</a> 2877 2876 <a href="#header.expect" class="smpl">expect-value</a> = <a href="#imported.abnf" class="smpl">token</a> / <a href="#imported.abnf" class="smpl">quoted-string</a> 2878 </pre><p id="rfc.section.1 0.11.p.3">If all received Expect header field(s) are syntactically valid but contain an expectation that the recipient does not understand2877 </pre><p id="rfc.section.11.11.p.3">If all received Expect header field(s) are syntactically valid but contain an expectation that the recipient does not understand 2879 2878 or cannot comply with, the recipient <em class="bcp14">MUST</em> respond with a <a href="#status.417" class="smpl">417 (Expectation Failed)</a> status code. A recipient of a syntactically invalid Expectation header field <em class="bcp14">MUST</em> respond with a <a href="#status.4xx" class="smpl">4xx</a> status code other than 417. 2880 2879 </p> 2881 <p id="rfc.section.1 0.11.p.4">The only expectation defined by this specification is:</p>2882 <p id="rfc.section.1 0.11.p.5"><span id="rfc.iref.142"></span><span id="rfc.iref.e.2"></span> 100-continue2880 <p id="rfc.section.11.11.p.4">The only expectation defined by this specification is:</p> 2881 <p id="rfc.section.11.11.p.5"><span id="rfc.iref.142"></span><span id="rfc.iref.e.2"></span> 100-continue 2883 2882 </p> 2884 2883 <ul class="empty"> … … 2886 2885 </li> 2887 2886 </ul> 2888 <p id="rfc.section.1 0.11.p.6">Comparison is case-insensitive for names (expect-name), and case-sensitive for values (expect-value).</p>2889 <p id="rfc.section.1 0.11.p.7">The Expect mechanism is hop-by-hop: the above requirements apply to any server, including proxies. However, the Expect header2887 <p id="rfc.section.11.11.p.6">Comparison is case-insensitive for names (expect-name), and case-sensitive for values (expect-value).</p> 2888 <p id="rfc.section.11.11.p.7">The Expect mechanism is hop-by-hop: the above requirements apply to any server, including proxies. However, the Expect header 2890 2889 field itself is end-to-end; it <em class="bcp14">MUST</em> be forwarded if the request is forwarded. 2891 2890 </p> 2892 <p id="rfc.section.1 0.11.p.8">Many older HTTP/1.0 and HTTP/1.1 applications do not understand the Expect header field.</p>2891 <p id="rfc.section.11.11.p.8">Many older HTTP/1.0 and HTTP/1.1 applications do not understand the Expect header field.</p> 2893 2892 <div id="rfc.iref.f.1"></div> 2894 2893 <div id="rfc.iref.h.13"></div> 2895 <h2 id="rfc.section.1 0.12"><a href="#rfc.section.10.12">10.12</a> <a id="header.from" href="#header.from">From</a></h2>2896 <p id="rfc.section.1 0.12.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>:2894 <h2 id="rfc.section.11.12"><a href="#rfc.section.11.12">11.12</a> <a id="header.from" href="#header.from">From</a></h2> 2895 <p id="rfc.section.11.12.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>: 2897 2896 </p> 2898 2897 <div id="rfc.figure.u.46"></div><pre class="inline"><span id="rfc.iref.g.53"></span> <a href="#header.from" class="smpl">From</a> = <a href="#header.from" class="smpl">mailbox</a> 2899 2898 2900 2899 <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>> 2901 </pre><p id="rfc.section.1 0.12.p.3">An example is:</p>2900 </pre><p id="rfc.section.11.12.p.3">An example is:</p> 2902 2901 <div id="rfc.figure.u.47"></div><pre class="text"> From: webmaster@example.org 2903 </pre><p id="rfc.section.1 0.12.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 performed2902 </pre><p id="rfc.section.11.12.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 2904 2903 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 2905 2904 end. 2906 2905 </p> 2907 <p id="rfc.section.1 0.12.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 original2906 <p id="rfc.section.11.12.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 2908 2907 issuer's address <em class="bcp14">SHOULD</em> be used. 2909 2908 </p> 2910 <p id="rfc.section.1 0.12.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's2909 <p id="rfc.section.11.12.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 2911 2910 security policy. It is strongly recommended that the user be able to disable, enable, and modify the value of this field at 2912 2911 any time prior to a request. … … 2914 2913 <div id="rfc.iref.l.1"></div> 2915 2914 <div id="rfc.iref.h.14"></div> 2916 <h2 id="rfc.section.1 0.13"><a href="#rfc.section.10.13">10.13</a> <a id="header.location" href="#header.location">Location</a></h2>2917 <p id="rfc.section.1 0.13.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.2915 <h2 id="rfc.section.11.13"><a href="#rfc.section.11.13">11.13</a> <a id="header.location" href="#header.location">Location</a></h2> 2916 <p id="rfc.section.11.13.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. 2918 2917 </p> 2919 2918 <div id="rfc.figure.u.48"></div><pre class="inline"><span id="rfc.iref.g.54"></span> <a href="#header.location" class="smpl">Location</a> = <a href="#imported.abnf" class="smpl">URI-reference</a> 2920 </pre><p id="rfc.section.1 0.13.p.3">For <a href="#status.201" class="smpl">201 (Created)</a> responses, the Location is the URI of the new resource which was created by the request. For <a href="#status.3xx" class="smpl">3xx (Redirection)</a> responses, the location <em class="bcp14">SHOULD</em> indicate the server's preferred URI for automatic redirection to the resource.2921 </p> 2922 <p id="rfc.section.1 0.13.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,2919 </pre><p id="rfc.section.11.13.p.3">For <a href="#status.201" class="smpl">201 (Created)</a> responses, the Location is the URI of the new resource which was created by the request. For <a href="#status.3xx" class="smpl">3xx (Redirection)</a> responses, the location <em class="bcp14">SHOULD</em> indicate the server's preferred URI for automatic redirection to the resource. 2920 </p> 2921 <p id="rfc.section.11.13.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, 2923 2922 then the original URI's fragment identifier is added to the final value. 2924 2923 </p> … … 2929 2928 <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 2930 2929 </pre> <p>would result in a final value of "http://www.example.net/index.html#larry", preserving the original fragment identifier.</p> 2931 <div class="note" id="rfc.section.1 0.13.p.7">2930 <div class="note" id="rfc.section.11.13.p.7"> 2932 2931 <p> <b>Note:</b> Some recipients attempt to recover from Location fields that are not valid URI references. This specification does not mandate 2933 2932 or define such processing, but does allow it. 2934 2933 </p> 2935 2934 </div> 2936 <p id="rfc.section.1 0.13.p.8">There are circumstances in which a fragment identifier in a Location URI would not be appropriate. For instance, when it appears2935 <p id="rfc.section.11.13.p.8">There are circumstances in which a fragment identifier in a Location URI would not be appropriate. For instance, when it appears 2937 2936 in a <a href="#status.201" class="smpl">201 2938 2937 (Created)</a> response, where the Location header field specifies the URI for the entire created resource. 2939 2938 </p> 2940 <div class="note" id="rfc.section.1 0.13.p.9">2941 <p> <b>Note:</b> The <a href="#header.content-location" class="smpl">Content-Location</a> header field (<a href="#header.content-location" id="rfc.xref.header.content-location.3" title="Content-Location">Section 1 0.8</a>) differs from Location in that the Content-Location identifies the most specific resource corresponding to the enclosed representation.2939 <div class="note" id="rfc.section.11.13.p.9"> 2940 <p> <b>Note:</b> The <a href="#header.content-location" class="smpl">Content-Location</a> header field (<a href="#header.content-location" id="rfc.xref.header.content-location.3" title="Content-Location">Section 11.8</a>) differs from Location in that the Content-Location identifies the most specific resource corresponding to the enclosed representation. 2942 2941 It is therefore possible for a response to contain header fields for both Location and Content-Location. 2943 2942 </p> … … 2945 2944 <div id="rfc.iref.m.9"></div> 2946 2945 <div id="rfc.iref.h.15"></div> 2947 <h2 id="rfc.section.1 0.14"><a href="#rfc.section.10.14">10.14</a> <a id="header.max-forwards" href="#header.max-forwards">Max-Forwards</a></h2>2948 <p id="rfc.section.1 0.14.p.1">The "Max-Forwards" header field provides a mechanism with the TRACE (<a href="#TRACE" id="rfc.xref.TRACE.2" title="TRACE">Section 4.3.8</a>) and OPTIONS (<a href="#OPTIONS" id="rfc.xref.OPTIONS.2" title="OPTIONS">Section 4.3.7</a>) methods to limit the number of times that the request is forwarded by proxies. This can be useful when the client is attempting2946 <h2 id="rfc.section.11.14"><a href="#rfc.section.11.14">11.14</a> <a id="header.max-forwards" href="#header.max-forwards">Max-Forwards</a></h2> 2947 <p id="rfc.section.11.14.p.1">The "Max-Forwards" header field provides a mechanism with the TRACE (<a href="#TRACE" id="rfc.xref.TRACE.2" title="TRACE">Section 4.3.8</a>) and OPTIONS (<a href="#OPTIONS" id="rfc.xref.OPTIONS.2" title="OPTIONS">Section 4.3.7</a>) methods to limit the number of times that the request is forwarded by proxies. This can be useful when the client is attempting 2949 2948 to trace a request which appears to be failing or looping mid-chain. 2950 2949 </p> 2951 2950 <div id="rfc.figure.u.51"></div><pre class="inline"><span id="rfc.iref.g.55"></span> <a href="#header.max-forwards" class="smpl">Max-Forwards</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a> 2952 </pre><p id="rfc.section.1 0.14.p.3">The Max-Forwards value is a decimal integer indicating the remaining number of times this request message can be forwarded.</p>2953 <p id="rfc.section.1 0.14.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).2954 </p> 2955 <p id="rfc.section.1 0.14.p.5">The Max-Forwards header field <em class="bcp14">MAY</em> be ignored for all other request methods.2951 </pre><p id="rfc.section.11.14.p.3">The Max-Forwards value is a decimal integer indicating the remaining number of times this request message can be forwarded.</p> 2952 <p id="rfc.section.11.14.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). 2953 </p> 2954 <p id="rfc.section.11.14.p.5">The Max-Forwards header field <em class="bcp14">MAY</em> be ignored for all other request methods. 2956 2955 </p> 2957 2956 <div id="rfc.iref.r.2"></div> 2958 2957 <div id="rfc.iref.h.16"></div> 2959 <h2 id="rfc.section.1 0.15"><a href="#rfc.section.10.15">10.15</a> <a id="header.referer" href="#header.referer">Referer</a></h2>2960 <p id="rfc.section.1 0.15.p.1">The "Referer" [sic] header field allows the client to specify the URI of the resource from which the target URI was obtained2958 <h2 id="rfc.section.11.15"><a href="#rfc.section.11.15">11.15</a> <a id="header.referer" href="#header.referer">Referer</a></h2> 2959 <p id="rfc.section.11.15.p.1">The "Referer" [sic] header field allows the client to specify the URI of the resource from which the target URI was obtained 2961 2960 (the "referrer", although the header field is misspelled.). 2962 2961 </p> 2963 <p id="rfc.section.1 0.15.p.2">The Referer header field allows servers to generate lists of back-links to resources for interest, logging, optimized caching,2962 <p id="rfc.section.11.15.p.2">The Referer header field allows servers to generate lists of back-links to resources for interest, logging, optimized caching, 2964 2963 etc. It also allows obsolete or mistyped links to be traced for maintenance. Some servers use Referer as a means of controlling 2965 2964 where they allow links from (so-called "deep linking"), but legitimate requests do not always contain a Referer header field. 2966 2965 </p> 2967 <p id="rfc.section.1 0.15.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 Referer2966 <p id="rfc.section.11.15.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 2968 2967 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 2969 2968 non-HTTP URIs (e.g., FTP). 2970 2969 </p> 2971 2970 <div id="rfc.figure.u.52"></div><pre class="inline"><span id="rfc.iref.g.56"></span> <a href="#header.referer" class="smpl">Referer</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a> 2972 </pre><p id="rfc.section.1 0.15.p.5">Example:</p>2971 </pre><p id="rfc.section.11.15.p.5">Example:</p> 2973 2972 <div id="rfc.figure.u.53"></div><pre class="text"> Referer: http://www.example.org/hypertext/Overview.html 2974 </pre><p id="rfc.section.1 0.15.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.2973 </pre><p id="rfc.section.11.15.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. 2975 2974 </p> 2976 2975 <div id="rfc.iref.r.3"></div> 2977 2976 <div id="rfc.iref.h.17"></div> 2978 <h2 id="rfc.section.1 0.16"><a href="#rfc.section.10.16">10.16</a> <a id="header.retry-after" href="#header.retry-after">Retry-After</a></h2>2979 <p id="rfc.section.1 0.16.p.1">The header "Retry-After" field can be used with a <a href="#status.503" class="smpl">503 (Service2977 <h2 id="rfc.section.11.16"><a href="#rfc.section.11.16">11.16</a> <a id="header.retry-after" href="#header.retry-after">Retry-After</a></h2> 2978 <p id="rfc.section.11.16.p.1">The header "Retry-After" field can be used with a <a href="#status.503" class="smpl">503 (Service 2980 2979 Unavailable)</a> response to indicate how long the service is expected to be unavailable to the requesting client. This field <em class="bcp14">MAY</em> also be used with any <a href="#status.3xx" class="smpl">3xx (Redirection)</a> response to indicate the minimum time the user-agent is asked to wait before issuing the redirected request. 2981 2980 </p> 2982 <p id="rfc.section.1 0.16.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>2981 <p id="rfc.section.11.16.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> 2983 2982 <div id="rfc.figure.u.54"></div><pre class="inline"><span id="rfc.iref.g.57"></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> 2984 2983 </pre><div id="rule.delta-seconds"> 2985 <p id="rfc.section.1 0.16.p.4"> Time spans are non-negative decimal integers, representing time in seconds.</p>2984 <p id="rfc.section.11.16.p.4"> Time spans are non-negative decimal integers, representing time in seconds.</p> 2986 2985 </div> 2987 2986 <div id="rfc.figure.u.55"></div><pre class="inline"><span id="rfc.iref.g.58"></span> <a href="#rule.delta-seconds" class="smpl">delta-seconds</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a> 2988 </pre><p id="rfc.section.1 0.16.p.6">Two examples of its use are</p>2987 </pre><p id="rfc.section.11.16.p.6">Two examples of its use are</p> 2989 2988 <div id="rfc.figure.u.56"></div><pre class="text"> Retry-After: Fri, 31 Dec 1999 23:59:59 GMT 2990 2989 Retry-After: 120 2991 </pre><p id="rfc.section.1 0.16.p.8">In the latter example, the delay is 2 minutes.</p>2990 </pre><p id="rfc.section.11.16.p.8">In the latter example, the delay is 2 minutes.</p> 2992 2991 <div id="rfc.iref.s.44"></div> 2993 2992 <div id="rfc.iref.h.18"></div> 2994 <h2 id="rfc.section.1 0.17"><a href="#rfc.section.10.17">10.17</a> <a id="header.server" href="#header.server">Server</a></h2>2995 <p id="rfc.section.1 0.17.p.1">The "Server" header field contains information about the software used by the origin server to handle the request.</p>2996 <p id="rfc.section.1 0.17.p.2">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section 7.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.29"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>) identifying the server and any significant subproducts. The product tokens are listed in order of their significance for2993 <h2 id="rfc.section.11.17"><a href="#rfc.section.11.17">11.17</a> <a id="header.server" href="#header.server">Server</a></h2> 2994 <p id="rfc.section.11.17.p.1">The "Server" header field contains information about the software used by the origin server to handle the request.</p> 2995 <p id="rfc.section.11.17.p.2">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section 8.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.29"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>) identifying the server and any significant subproducts. The product tokens are listed in order of their significance for 2997 2996 identifying the application. 2998 2997 </p> 2999 2998 <div id="rfc.figure.u.57"></div><pre class="inline"><span id="rfc.iref.g.59"></span> <a href="#header.server" class="smpl">Server</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) ) 3000 </pre><p id="rfc.section.1 0.17.p.4">Example:</p>2999 </pre><p id="rfc.section.11.17.p.4">Example:</p> 3001 3000 <div id="rfc.figure.u.58"></div><pre class="text"> Server: CERN/3.0 libwww/2.17 3002 </pre><p id="rfc.section.1 0.17.p.6">If the response is being forwarded through a proxy, the proxy application <em class="bcp14">MUST NOT</em> modify the <a href="#header.server" class="smpl">Server</a> header field. Instead, it <em class="bcp14">MUST</em> include a <a href="p1-messaging.html#header.via" class="smpl">Via</a> field (as described in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.30"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>).3003 </p> 3004 <div class="note" id="rfc.section.1 0.17.p.7">3001 </pre><p id="rfc.section.11.17.p.6">If the response is being forwarded through a proxy, the proxy application <em class="bcp14">MUST NOT</em> modify the <a href="#header.server" class="smpl">Server</a> header field. Instead, it <em class="bcp14">MUST</em> include a <a href="p1-messaging.html#header.via" class="smpl">Via</a> field (as described in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.30"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). 3002 </p> 3003 <div class="note" id="rfc.section.11.17.p.7"> 3005 3004 <p> <b>Note:</b> Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks 3006 3005 against software that is known to contain security holes. Server implementers are encouraged to make this field a configurable … … 3010 3009 <div id="rfc.iref.u.1"></div> 3011 3010 <div id="rfc.iref.h.19"></div> 3012 <h2 id="rfc.section.1 0.18"><a href="#rfc.section.10.18">10.18</a> <a id="header.user-agent" href="#header.user-agent">User-Agent</a></h2>3013 <p id="rfc.section.1 0.18.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.3014 </p> 3015 <p id="rfc.section.1 0.18.p.2">Typically, it is used for statistical purposes, the tracing of protocol violations, and tailoring responses to avoid particular3011 <h2 id="rfc.section.11.18"><a href="#rfc.section.11.18">11.18</a> <a id="header.user-agent" href="#header.user-agent">User-Agent</a></h2> 3012 <p id="rfc.section.11.18.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. 3013 </p> 3014 <p id="rfc.section.11.18.p.2">Typically, it is used for statistical purposes, the tracing of protocol violations, and tailoring responses to avoid particular 3016 3015 user agent limitations. 3017 3016 </p> 3018 <p id="rfc.section.1 0.18.p.3">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section 7.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.31"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>) identifying the agent and its significant subproducts. By convention, the product tokens are listed in order of their significance3017 <p id="rfc.section.11.18.p.3">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section 8.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.31"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>) identifying the agent and its significant subproducts. By convention, the product tokens are listed in order of their significance 3019 3018 for identifying the application. 3020 3019 </p> 3021 <p id="rfc.section.1 0.18.p.4">Because this field is usually sent on every request a user agent makes, implementations are encouraged not to include needlessly3020 <p id="rfc.section.11.18.p.4">Because this field is usually sent on every request a user agent makes, implementations are encouraged not to include needlessly 3022 3021 fine-grained detail, and to limit (or even prohibit) the addition of subproducts by third parties. Overly long and detailed 3023 3022 User-Agent field values make requests larger and can also be used to identify ("fingerprint") the user against their wishes. 3024 3023 </p> 3025 <p id="rfc.section.1 0.18.p.5">Likewise, implementations are encouraged not to use the product tokens of other implementations in order to declare compatibility3024 <p id="rfc.section.11.18.p.5">Likewise, implementations are encouraged not to use the product tokens of other implementations in order to declare compatibility 3026 3025 with them, as this circumvents the purpose of the field. Finally, they are encouraged not to use comments to identify products; 3027 3026 doing so makes the field value more difficult to parse. 3028 3027 </p> 3029 3028 <div id="rfc.figure.u.59"></div><pre class="inline"><span id="rfc.iref.g.60"></span> <a href="#header.user-agent" class="smpl">User-Agent</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) ) 3030 </pre><p id="rfc.section.1 0.18.p.7">Example:</p>3029 </pre><p id="rfc.section.11.18.p.7">Example:</p> 3031 3030 <div id="rfc.figure.u.60"></div><pre class="text"> User-Agent: CERN-LineMode/2.15 libwww/2.17b3 3032 </pre><h1 id="rfc.section.1 1"><a href="#rfc.section.11">11.</a> <a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1>3033 <h2 id="rfc.section.1 1.1"><a href="#rfc.section.11.1">11.1</a> <a id="method.registry" href="#method.registry">Method Registry</a></h2>3034 <p id="rfc.section.1 1.1.p.1">The HTTP Method Registry defines the name space for the request method token (<a href="#methods" title="Request Methods">Section 4</a>). The method registry is maintained at <<a href="http://www.iana.org/assignments/http-methods">http://www.iana.org/assignments/http-methods</a>>.3035 </p> 3036 <h3 id="rfc.section.1 1.1.1"><a href="#rfc.section.11.1.1">11.1.1</a> <a id="method.procedure" href="#method.procedure">Procedure</a></h3>3037 <p id="rfc.section.1 1.1.1.p.1">HTTP method registrations <em class="bcp14">MUST</em> include the following fields:3031 </pre><h1 id="rfc.section.12"><a href="#rfc.section.12">12.</a> <a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1> 3032 <h2 id="rfc.section.12.1"><a href="#rfc.section.12.1">12.1</a> <a id="method.registry" href="#method.registry">Method Registry</a></h2> 3033 <p id="rfc.section.12.1.p.1">The HTTP Method Registry defines the name space for the request method token (<a href="#methods" title="Request Methods">Section 4</a>). The method registry is maintained at <<a href="http://www.iana.org/assignments/http-methods">http://www.iana.org/assignments/http-methods</a>>. 3034 </p> 3035 <h3 id="rfc.section.12.1.1"><a href="#rfc.section.12.1.1">12.1.1</a> <a id="method.procedure" href="#method.procedure">Procedure</a></h3> 3036 <p id="rfc.section.12.1.1.p.1">HTTP method registrations <em class="bcp14">MUST</em> include the following fields: 3038 3037 </p> 3039 3038 <ul> … … 3046 3045 <li>Pointer to specification text</li> 3047 3046 </ul> 3048 <p id="rfc.section.1 1.1.1.p.2">Values to be added to this name space require IETF Review (see <a href="#RFC5226" id="rfc.xref.RFC5226.1"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>).3049 </p> 3050 <h3 id="rfc.section.1 1.1.2"><a href="#rfc.section.11.1.2">11.1.2</a> <a id="considerations.for.new.methods" href="#considerations.for.new.methods">Considerations for New Methods</a></h3>3051 <p id="rfc.section.1 1.1.2.p.1">Standardized HTTP methods are generic; that is, they are potentially applicable to any resource, not just one particular media3047 <p id="rfc.section.12.1.1.p.2">Values to be added to this name space require IETF Review (see <a href="#RFC5226" id="rfc.xref.RFC5226.1"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>). 3048 </p> 3049 <h3 id="rfc.section.12.1.2"><a href="#rfc.section.12.1.2">12.1.2</a> <a id="considerations.for.new.methods" href="#considerations.for.new.methods">Considerations for New Methods</a></h3> 3050 <p id="rfc.section.12.1.2.p.1">Standardized HTTP methods are generic; that is, they are potentially applicable to any resource, not just one particular media 3052 3051 type, kind of resource, or application. As such, it is preferred that new HTTP methods be registered in a document that isn't 3053 3052 specific to a single application or data format, since orthogonal technologies deserve orthogonal specification. 3054 3053 </p> 3055 <p id="rfc.section.1 1.1.2.p.2">Since HTTP message parsing (<a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.32"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>) is independent of method semantics (aside from responses to HEAD), definitions of new HTTP methods cannot change the parsing3054 <p id="rfc.section.12.1.2.p.2">Since HTTP message parsing (<a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.32"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>) is independent of method semantics (aside from responses to HEAD), definitions of new HTTP methods cannot change the parsing 3056 3055 algorithm or prohibit the presence of a message body on either the request or the response message. Definitions of new methods 3057 3056 can specify that only zero-length bodies are allowed, which would imply that each such messages would be required to contain 3058 3057 a Content-Length header field with a value of "0". 3059 3058 </p> 3060 <p id="rfc.section.1 1.1.2.p.3">New method definitions need to indicate whether they are safe (<a href="#safe.methods" title="Safe Methods">Section 4.2.1</a>), idempotent (<a href="#idempotent.methods" title="Idempotent Methods">Section 4.2.2</a>), cacheable (<a href="#cacheable.methods" title="Cacheable Methods">Section 4.2.3</a>), and what semantics are to be associated with the request body if any is present in the request. If a method is cacheable,3059 <p id="rfc.section.12.1.2.p.3">New method definitions need to indicate whether they are safe (<a href="#safe.methods" title="Safe Methods">Section 4.2.1</a>), idempotent (<a href="#idempotent.methods" title="Idempotent Methods">Section 4.2.2</a>), cacheable (<a href="#cacheable.methods" title="Cacheable Methods">Section 4.2.3</a>), and what semantics are to be associated with the request body if any is present in the request. If a method is cacheable, 3061 3060 the method definition ought to describe how, and under what conditions, a cache can store a response and use it to satisfy 3062 3061 a subsequent request. 3063 3062 </p> 3064 <h3 id="rfc.section.1 1.1.3"><a href="#rfc.section.11.1.3">11.1.3</a> <a id="method.registration" href="#method.registration">Registrations</a></h3>3065 <p id="rfc.section.1 1.1.3.p.1">The HTTP Method Registry shall be populated with the registrations below:</p>3063 <h3 id="rfc.section.12.1.3"><a href="#rfc.section.12.1.3">12.1.3</a> <a id="method.registration" href="#method.registration">Registrations</a></h3> 3064 <p id="rfc.section.12.1.3.p.1">The HTTP Method Registry shall be populated with the registrations below:</p> 3066 3065 <div id="rfc.table.2"> 3067 3066 <div id="iana.method.registration.table"></div> … … 3135 3134 </table> 3136 3135 </div> 3137 <h2 id="rfc.section.1 1.2"><a href="#rfc.section.11.2">11.2</a> <a id="status.code.registry" href="#status.code.registry">Status Code Registry</a></h2>3138 <p id="rfc.section.1 1.2.p.1">The HTTP Status Code Registry defines the name space for the response status-code token (<a href="#status.codes" title="Response Status Codes">Section 6</a>). The status code registry is maintained at <<a href="http://www.iana.org/assignments/http-status-codes">http://www.iana.org/assignments/http-status-codes</a>>.3139 </p> 3140 <p id="rfc.section.1 1.2.p.2">This section replaces 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>.3141 </p> 3142 <h3 id="rfc.section.1 1.2.1"><a href="#rfc.section.11.2.1">11.2.1</a> <a id="status.code.procedure" href="#status.code.procedure">Procedure</a></h3>3143 <p id="rfc.section.1 1.2.1.p.1">Values to be added to the HTTP status code name space require IETF Review (see <a href="#RFC5226" id="rfc.xref.RFC5226.2"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>).3144 </p> 3145 <h3 id="rfc.section.1 1.2.2"><a href="#rfc.section.11.2.2">11.2.2</a> <a id="considerations.for.new.status.codes" href="#considerations.for.new.status.codes">Considerations for New Status Codes</a></h3>3146 <p id="rfc.section.1 1.2.2.p.1">When it is necessary to express new semantics for a HTTP response that aren't specific to a single application or media type,3136 <h2 id="rfc.section.12.2"><a href="#rfc.section.12.2">12.2</a> <a id="status.code.registry" href="#status.code.registry">Status Code Registry</a></h2> 3137 <p id="rfc.section.12.2.p.1">The HTTP Status Code Registry defines the name space for the response status-code token (<a href="#status.codes" title="Response Status Codes">Section 6</a>). The status code registry is maintained at <<a href="http://www.iana.org/assignments/http-status-codes">http://www.iana.org/assignments/http-status-codes</a>>. 3138 </p> 3139 <p id="rfc.section.12.2.p.2">This section replaces 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>. 3140 </p> 3141 <h3 id="rfc.section.12.2.1"><a href="#rfc.section.12.2.1">12.2.1</a> <a id="status.code.procedure" href="#status.code.procedure">Procedure</a></h3> 3142 <p id="rfc.section.12.2.1.p.1">Values to be added to the HTTP status code name space require IETF Review (see <a href="#RFC5226" id="rfc.xref.RFC5226.2"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>). 3143 </p> 3144 <h3 id="rfc.section.12.2.2"><a href="#rfc.section.12.2.2">12.2.2</a> <a id="considerations.for.new.status.codes" href="#considerations.for.new.status.codes">Considerations for New Status Codes</a></h3> 3145 <p id="rfc.section.12.2.2.p.1">When it is necessary to express new semantics for a HTTP response that aren't specific to a single application or media type, 3147 3146 and currently defined status codes are inadequate, a new status code can be registered. 3148 3147 </p> 3149 <p id="rfc.section.1 1.2.2.p.2">HTTP status codes are generic; that is, they are potentially applicable to any resource, not just one particular media type,3148 <p id="rfc.section.12.2.2.p.2">HTTP status codes are generic; that is, they are potentially applicable to any resource, not just one particular media type, 3150 3149 "type" of resource, or application. As such, it is preferred that new HTTP status codes be registered in a document that isn't 3151 3150 specific to a single application, so that this is clear. 3152 3151 </p> 3153 <p id="rfc.section.1 1.2.2.p.3">Definitions of new HTTP status codes typically explain the request conditions that produce a response containing the status3152 <p id="rfc.section.12.2.2.p.3">Definitions of new HTTP status codes typically explain the request conditions that produce a response containing the status 3154 3153 code (e.g., combinations of request header fields and/or method(s)), along with any interactions with response header fields 3155 3154 (e.g., those that are required, those that modify the semantics of the response). 3156 3155 </p> 3157 <p id="rfc.section.1 1.2.2.p.4">New HTTP status codes are required to fall under one of the categories defined in <a href="#status.codes" title="Response Status Codes">Section 6</a>. To allow existing parsers to properly handle them, new status codes cannot disallow a response body, although they can mandate3156 <p id="rfc.section.12.2.2.p.4">New HTTP status codes are required to fall under one of the categories defined in <a href="#status.codes" title="Response Status Codes">Section 6</a>. To allow existing parsers to properly handle them, new status codes cannot disallow a response body, although they can mandate 3158 3157 a zero-length response body. They can require the presence of one or more particular HTTP response header field(s). 3159 3158 </p> 3160 <p id="rfc.section.1 1.2.2.p.5">Likewise, their definitions can specify that caches are allowed to use heuristics to determine their freshness (see <a href="#Part6" id="rfc.xref.Part6.18"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>; by default, it is not allowed), and can define how to determine the resource which they carry a representation for (see <a href="#identifying.response.associated.with.representation" title="Identifying the Resource Associated with a Representation">Section 3.1</a>; by default, it is anonymous).3161 </p> 3162 <h3 id="rfc.section.1 1.2.3"><a href="#rfc.section.11.2.3">11.2.3</a> <a id="status.code.registration" href="#status.code.registration">Registrations</a></h3>3163 <p id="rfc.section.1 1.2.3.p.1">The HTTP Status Code Registry shall be updated with the registrations below:</p>3159 <p id="rfc.section.12.2.2.p.5">Likewise, their definitions can specify that caches are allowed to use heuristics to determine their freshness (see <a href="#Part6" id="rfc.xref.Part6.18"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>; by default, it is not allowed), and can define how to determine the resource which they carry a representation for (see <a href="#identifying.response.associated.with.representation" title="Identifying the Resource Associated with a Representation">Section 3.1</a>; by default, it is anonymous). 3160 </p> 3161 <h3 id="rfc.section.12.2.3"><a href="#rfc.section.12.2.3">12.2.3</a> <a id="status.code.registration" href="#status.code.registration">Registrations</a></h3> 3162 <p id="rfc.section.12.2.3.p.1">The HTTP Status Code Registry shall be updated with the registrations below:</p> 3164 3163 <div id="rfc.table.3"> 3165 3164 <div id="iana.status.code.registration.table"></div> … … 3392 3391 </table> 3393 3392 </div> 3394 <h2 id="rfc.section.1 1.3"><a href="#rfc.section.11.3">11.3</a> <a id="header.field.registry" href="#header.field.registry">Header Field Registry</a></h2>3395 <p id="rfc.section.1 1.3.p.1">HTTP header fields are registered within 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>>, as defined by <a href="#RFC3864" id="rfc.xref.RFC3864.1"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>.3396 </p> 3397 <h3 id="rfc.section.1 1.3.1"><a href="#rfc.section.11.3.1">11.3.1</a> <a id="considerations.for.new.header.fields" href="#considerations.for.new.header.fields">Considerations for New Header Fields</a></h3>3398 <p id="rfc.section.1 1.3.1.p.1">Header fields are key:value pairs that can be used to communicate data about the message, its payload, the target resource,3393 <h2 id="rfc.section.12.3"><a href="#rfc.section.12.3">12.3</a> <a id="header.field.registry" href="#header.field.registry">Header Field Registry</a></h2> 3394 <p id="rfc.section.12.3.p.1">HTTP header fields are registered within 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>>, as defined by <a href="#RFC3864" id="rfc.xref.RFC3864.1"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>. 3395 </p> 3396 <h3 id="rfc.section.12.3.1"><a href="#rfc.section.12.3.1">12.3.1</a> <a id="considerations.for.new.header.fields" href="#considerations.for.new.header.fields">Considerations for New Header Fields</a></h3> 3397 <p id="rfc.section.12.3.1.p.1">Header fields are key:value pairs that can be used to communicate data about the message, its payload, the target resource, 3399 3398 or the connection (i.e., control data). See <a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.33"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a> for a general definition of header field syntax in HTTP messages. 3400 3399 </p> 3401 <p id="rfc.section.1 1.3.1.p.2">The requirements for header field names are defined in <a href="http://tools.ietf.org/html/rfc3864#section-4.1">Section 4.1</a> of <a href="#RFC3864" id="rfc.xref.RFC3864.2"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>. Authors of specifications defining new fields are advised to keep the name as short as practical, and not to prefix them3400 <p id="rfc.section.12.3.1.p.2">The requirements for header field names are defined in <a href="http://tools.ietf.org/html/rfc3864#section-4.1">Section 4.1</a> of <a href="#RFC3864" id="rfc.xref.RFC3864.2"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>. Authors of specifications defining new fields are advised to keep the name as short as practical, and not to prefix them 3402 3401 with "X-" if they are to be registered (either immediately or in the future). 3403 3402 </p> 3404 <p id="rfc.section.1 1.3.1.p.3">New header field values typically have their syntax defined using ABNF (<a href="#RFC5234" id="rfc.xref.RFC5234.2"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>), using the extension defined in <a href="p1-messaging.html#abnf.extension" title="ABNF list extension: #rule">Appendix B</a> of <a href="#Part1" id="rfc.xref.Part1.34"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a> as necessary, and are usually constrained to the range of ASCII characters. Header fields needing a greater range of characters3403 <p id="rfc.section.12.3.1.p.3">New header field values typically have their syntax defined using ABNF (<a href="#RFC5234" id="rfc.xref.RFC5234.2"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>), using the extension defined in <a href="p1-messaging.html#abnf.extension" title="ABNF list extension: #rule">Appendix B</a> of <a href="#Part1" id="rfc.xref.Part1.34"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a> as necessary, and are usually constrained to the range of ASCII characters. Header fields needing a greater range of characters 3405 3404 can use an encoding such as the one defined in <a href="#RFC5987" id="rfc.xref.RFC5987.1"><cite title="Character Set and Language Encoding for Hypertext Transfer Protocol (HTTP) Header Field Parameters">[RFC5987]</cite></a>. 3406 3405 </p> 3407 <p id="rfc.section.1 1.3.1.p.4">Because commas (",") are used as a generic delimiter between field-values, they need to be treated with care if they are allowed3406 <p id="rfc.section.12.3.1.p.4">Because commas (",") are used as a generic delimiter between field-values, they need to be treated with care if they are allowed 3408 3407 in the field-value's payload. Typically, components that might contain a comma are protected with double-quotes using the 3409 3408 quoted-string ABNF production (<a href="p1-messaging.html#field.components" title="Field value components">Section 3.2.4</a> of <a href="#Part1" id="rfc.xref.Part1.35"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). 3410 3409 </p> 3411 <p id="rfc.section.1 1.3.1.p.5">For example, a textual date and a URI (either of which might contain a comma) could be safely carried in field-values like3410 <p id="rfc.section.12.3.1.p.5">For example, a textual date and a URI (either of which might contain a comma) could be safely carried in field-values like 3412 3411 these: 3413 3412 </p> … … 3415 3414 "http://without-a-comma.example.com/" 3416 3415 Example-Date-Field: "Sat, 04 May 1996", "Wed, 14 Sep 2005" 3417 </pre><p id="rfc.section.1 1.3.1.p.7">Note that double-quote delimiters almost always are used with the quoted-string production; using a different syntax inside3416 </pre><p id="rfc.section.12.3.1.p.7">Note that double-quote delimiters almost always are used with the quoted-string production; using a different syntax inside 3418 3417 double-quotes will likely cause unnecessary confusion. 3419 3418 </p> 3420 <p id="rfc.section.1 1.3.1.p.8">Many header fields use a format including (case-insensitively) named parameters (for instance, <a href="#header.content-type" class="smpl">Content-Type</a>, defined in <a href="#header.content-type" id="rfc.xref.header.content-type.4" title="Content-Type">Section 10.9</a>). Allowing both unquoted (token) and quoted (quoted-string) syntax for the parameter value enables recipients to use existing3419 <p id="rfc.section.12.3.1.p.8">Many header fields use a format including (case-insensitively) named parameters (for instance, <a href="#header.content-type" class="smpl">Content-Type</a>, defined in <a href="#header.content-type" id="rfc.xref.header.content-type.4" title="Content-Type">Section 11.9</a>). Allowing both unquoted (token) and quoted (quoted-string) syntax for the parameter value enables recipients to use existing 3421 3420 parser components. When allowing both forms, the meaning of a parameter value ought to be independent of the syntax used for 3422 it (for an example, see the notes on parameter handling for media types in <a href="#media.types" title="Media Types">Section 7.5</a>).3423 </p> 3424 <p id="rfc.section.1 1.3.1.p.9">Authors of specifications defining new header fields are advised to consider documenting: </p>3421 it (for an example, see the notes on parameter handling for media types in <a href="#media.types" title="Media Types">Section 8.5</a>). 3422 </p> 3423 <p id="rfc.section.12.3.1.p.9">Authors of specifications defining new header fields are advised to consider documenting: </p> 3425 3424 <ul> 3426 3425 <li> … … 3459 3458 </li> 3460 3459 </ul> 3461 <h3 id="rfc.section.1 1.3.2"><a href="#rfc.section.11.3.2">11.3.2</a> <a id="header.field.registration" href="#header.field.registration">Registrations</a></h3>3462 <p id="rfc.section.1 1.3.2.p.1">The Message Header Field Registry shall be updated with the following permanent registrations:</p>3460 <h3 id="rfc.section.12.3.2"><a href="#rfc.section.12.3.2">12.3.2</a> <a id="header.field.registration" href="#header.field.registration">Registrations</a></h3> 3461 <p id="rfc.section.12.3.2.p.1">The Message Header Field Registry shall be updated with the following permanent registrations:</p> 3463 3462 <div id="rfc.table.4"> 3464 3463 <div id="iana.header.registration.table"></div> … … 3477 3476 <td class="left">http</td> 3478 3477 <td class="left">standard</td> 3479 <td class="left"> <a href="#header.accept" id="rfc.xref.header.accept.4" title="Accept">Section 1 0.1</a>3478 <td class="left"> <a href="#header.accept" id="rfc.xref.header.accept.4" title="Accept">Section 11.1</a> 3480 3479 </td> 3481 3480 </tr> … … 3484 3483 <td class="left">http</td> 3485 3484 <td class="left">standard</td> 3486 <td class="left"> <a href="#header.accept-charset" id="rfc.xref.header.accept-charset.3" title="Accept-Charset">Section 1 0.2</a>3485 <td class="left"> <a href="#header.accept-charset" id="rfc.xref.header.accept-charset.3" title="Accept-Charset">Section 11.2</a> 3487 3486 </td> 3488 3487 </tr> … … 3491 3490 <td class="left">http</td> 3492 3491 <td class="left">standard</td> 3493 <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.4" title="Accept-Encoding">Section 1 0.3</a>3492 <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.4" title="Accept-Encoding">Section 11.3</a> 3494 3493 </td> 3495 3494 </tr> … … 3498 3497 <td class="left">http</td> 3499 3498 <td class="left">standard</td> 3500 <td class="left"> <a href="#header.accept-language" id="rfc.xref.header.accept-language.3" title="Accept-Language">Section 1 0.4</a>3499 <td class="left"> <a href="#header.accept-language" id="rfc.xref.header.accept-language.3" title="Accept-Language">Section 11.4</a> 3501 3500 </td> 3502 3501 </tr> … … 3505 3504 <td class="left">http</td> 3506 3505 <td class="left">standard</td> 3507 <td class="left"> <a href="#header.allow" id="rfc.xref.header.allow.3" title="Allow">Section 1 0.5</a>3506 <td class="left"> <a href="#header.allow" id="rfc.xref.header.allow.3" title="Allow">Section 11.5</a> 3508 3507 </td> 3509 3508 </tr> … … 3512 3511 <td class="left">http</td> 3513 3512 <td class="left">standard</td> 3514 <td class="left"> <a href="#header.content-encoding" id="rfc.xref.header.content-encoding.3" title="Content-Encoding">Section 1 0.6</a>3513 <td class="left"> <a href="#header.content-encoding" id="rfc.xref.header.content-encoding.3" title="Content-Encoding">Section 11.6</a> 3515 3514 </td> 3516 3515 </tr> … … 3519 3518 <td class="left">http</td> 3520 3519 <td class="left">standard</td> 3521 <td class="left"> <a href="#header.content-language" id="rfc.xref.header.content-language.2" title="Content-Language">Section 1 0.7</a>3520 <td class="left"> <a href="#header.content-language" id="rfc.xref.header.content-language.2" title="Content-Language">Section 11.7</a> 3522 3521 </td> 3523 3522 </tr> … … 3526 3525 <td class="left">http</td> 3527 3526 <td class="left">standard</td> 3528 <td class="left"> <a href="#header.content-location" id="rfc.xref.header.content-location.4" title="Content-Location">Section 1 0.8</a>3527 <td class="left"> <a href="#header.content-location" id="rfc.xref.header.content-location.4" title="Content-Location">Section 11.8</a> 3529 3528 </td> 3530 3529 </tr> … … 3533 3532 <td class="left">http</td> 3534 3533 <td class="left">standard</td> 3535 <td class="left"> <a href="#header.content-type" id="rfc.xref.header.content-type.5" title="Content-Type">Section 1 0.9</a>3534 <td class="left"> <a href="#header.content-type" id="rfc.xref.header.content-type.5" title="Content-Type">Section 11.9</a> 3536 3535 </td> 3537 3536 </tr> … … 3540 3539 <td class="left">http</td> 3541 3540 <td class="left">standard</td> 3542 <td class="left"> <a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section 1 0.10</a>3541 <td class="left"> <a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section 11.10</a> 3543 3542 </td> 3544 3543 </tr> … … 3547 3546 <td class="left">http</td> 3548 3547 <td class="left">standard</td> 3549 <td class="left"> <a href="#header.expect" id="rfc.xref.header.expect.3" title="Expect">Section 1 0.11</a>3548 <td class="left"> <a href="#header.expect" id="rfc.xref.header.expect.3" title="Expect">Section 11.11</a> 3550 3549 </td> 3551 3550 </tr> … … 3554 3553 <td class="left">http</td> 3555 3554 <td class="left">standard</td> 3556 <td class="left"> <a href="#header.from" id="rfc.xref.header.from.2" title="From">Section 1 0.12</a>3555 <td class="left"> <a href="#header.from" id="rfc.xref.header.from.2" title="From">Section 11.12</a> 3557 3556 </td> 3558 3557 </tr> … … 3561 3560 <td class="left">http</td> 3562 3561 <td class="left">standard</td> 3563 <td class="left"> <a href="#header.location" id="rfc.xref.header.location.4" title="Location">Section 1 0.13</a>3562 <td class="left"> <a href="#header.location" id="rfc.xref.header.location.4" title="Location">Section 11.13</a> 3564 3563 </td> 3565 3564 </tr> … … 3575 3574 <td class="left">http</td> 3576 3575 <td class="left">standard</td> 3577 <td class="left"> <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.4" title="Max-Forwards">Section 1 0.14</a>3576 <td class="left"> <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.4" title="Max-Forwards">Section 11.14</a> 3578 3577 </td> 3579 3578 </tr> … … 3582 3581 <td class="left">http</td> 3583 3582 <td class="left">standard</td> 3584 <td class="left"> <a href="#header.referer" id="rfc.xref.header.referer.2" title="Referer">Section 1 0.15</a>3583 <td class="left"> <a href="#header.referer" id="rfc.xref.header.referer.2" title="Referer">Section 11.15</a> 3585 3584 </td> 3586 3585 </tr> … … 3589 3588 <td class="left">http</td> 3590 3589 <td class="left">standard</td> 3591 <td class="left"> <a href="#header.retry-after" id="rfc.xref.header.retry-after.3" title="Retry-After">Section 1 0.16</a>3590 <td class="left"> <a href="#header.retry-after" id="rfc.xref.header.retry-after.3" title="Retry-After">Section 11.16</a> 3592 3591 </td> 3593 3592 </tr> … … 3596 3595 <td class="left">http</td> 3597 3596 <td class="left">standard</td> 3598 <td class="left"> <a href="#header.server" id="rfc.xref.header.server.2" title="Server">Section 1 0.17</a>3597 <td class="left"> <a href="#header.server" id="rfc.xref.header.server.2" title="Server">Section 11.17</a> 3599 3598 </td> 3600 3599 </tr> … … 3603 3602 <td class="left">http</td> 3604 3603 <td class="left">standard</td> 3605 <td class="left"> <a href="#header.user-agent" id="rfc.xref.header.user-agent.3" title="User-Agent">Section 1 0.18</a>3604 <td class="left"> <a href="#header.user-agent" id="rfc.xref.header.user-agent.3" title="User-Agent">Section 11.18</a> 3606 3605 </td> 3607 3606 </tr> … … 3609 3608 </table> 3610 3609 </div> 3611 <p id="rfc.section.1 1.3.2.p.2">The change controller for the above registrations is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>3612 <h2 id="rfc.section.1 1.4"><a href="#rfc.section.11.4">11.4</a> <a id="content.coding.registry" href="#content.coding.registry">Content Coding Registry</a></h2>3613 <p id="rfc.section.1 1.4.p.1">The HTTP Content Coding Registry defines the name space for content coding names (<a href="p1-messaging.html#compression.codings" title="Compression Codings">Section 4.2</a> of <a href="#Part1" id="rfc.xref.Part1.39"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). The content coding registry is maintained at <<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>>.3614 </p> 3615 <h3 id="rfc.section.1 1.4.1"><a href="#rfc.section.11.4.1">11.4.1</a> <a id="content.coding.procedure" href="#content.coding.procedure">Procedure</a></h3>3616 <p id="rfc.section.1 1.4.1.p.1">Content Coding registrations <em class="bcp14">MUST</em> include the following fields:3610 <p id="rfc.section.12.3.2.p.2">The change controller for the above registrations is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p> 3611 <h2 id="rfc.section.12.4"><a href="#rfc.section.12.4">12.4</a> <a id="content.coding.registry" href="#content.coding.registry">Content Coding Registry</a></h2> 3612 <p id="rfc.section.12.4.p.1">The HTTP Content Coding Registry defines the name space for content coding names (<a href="p1-messaging.html#compression.codings" title="Compression Codings">Section 4.2</a> of <a href="#Part1" id="rfc.xref.Part1.39"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). The content coding registry is maintained at <<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>>. 3613 </p> 3614 <h3 id="rfc.section.12.4.1"><a href="#rfc.section.12.4.1">12.4.1</a> <a id="content.coding.procedure" href="#content.coding.procedure">Procedure</a></h3> 3615 <p id="rfc.section.12.4.1.p.1">Content Coding registrations <em class="bcp14">MUST</em> include the following fields: 3617 3616 </p> 3618 3617 <ul> … … 3621 3620 <li>Pointer to specification text</li> 3622 3621 </ul> 3623 <p id="rfc.section.1 1.4.1.p.2">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.Part1.40"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[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.Part1.41"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>).3624 </p> 3625 <p id="rfc.section.1 1.4.1.p.3">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.3626 </p> 3627 <h3 id="rfc.section.1 1.4.2"><a href="#rfc.section.11.4.2">11.4.2</a> <a id="content.coding.registration" href="#content.coding.registration">Registrations</a></h3>3628 <p id="rfc.section.1 1.4.2.p.1">The HTTP Content Codings Registry shall be updated with the registrations below:</p>3622 <p id="rfc.section.12.4.1.p.2">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.Part1.40"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[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.Part1.41"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>). 3623 </p> 3624 <p id="rfc.section.12.4.1.p.3">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. 3625 </p> 3626 <h3 id="rfc.section.12.4.2"><a href="#rfc.section.12.4.2">12.4.2</a> <a id="content.coding.registration" href="#content.coding.registration">Registrations</a></h3> 3627 <p id="rfc.section.12.4.2.p.1">The HTTP Content Codings Registry shall be updated with the registrations below:</p> 3629 3628 <div id="rfc.table.5"> 3630 3629 <div id="iana.content.coding.registration.table"></div> … … 3661 3660 <td class="left">reserved (synonym for "no encoding" in <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> header field) 3662 3661 </td> 3663 <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.5" title="Accept-Encoding">Section 1 0.3</a>3662 <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.5" title="Accept-Encoding">Section 11.3</a> 3664 3663 </td> 3665 3664 </tr> … … 3667 3666 </table> 3668 3667 </div> 3669 <h1 id="rfc.section.1 2"><a href="#rfc.section.12">12.</a> <a id="security.considerations" href="#security.considerations">Security Considerations</a></h1>3670 <p id="rfc.section.1 2.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.13668 <h1 id="rfc.section.13"><a href="#rfc.section.13">13.</a> <a id="security.considerations" href="#security.considerations">Security Considerations</a></h1> 3669 <p id="rfc.section.13.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.1 3671 3670 as described by this document. The discussion does not include definitive solutions to the problems revealed, though it does 3672 3671 make some suggestions for reducing security risks. 3673 3672 </p> 3674 <h2 id="rfc.section.1 2.1"><a href="#rfc.section.12.1">12.1</a> <a id="security.sensitive" href="#security.sensitive">Transfer of Sensitive Information</a></h2>3675 <p id="rfc.section.1 2.1.p.1">Like any generic data transfer protocol, HTTP cannot regulate the content of the data that is transferred, nor is there any3673 <h2 id="rfc.section.13.1"><a href="#rfc.section.13.1">13.1</a> <a id="security.sensitive" href="#security.sensitive">Transfer of Sensitive Information</a></h2> 3674 <p id="rfc.section.13.1.p.1">Like any generic data transfer protocol, HTTP cannot regulate the content of the data that is transferred, nor is there any 3676 3675 a priori method of determining the sensitivity of any particular piece of information within the context of any given request. 3677 3676 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 3678 3677 special mention in this context: <a href="#header.server" class="smpl">Server</a>, <a href="p1-messaging.html#header.via" class="smpl">Via</a>, <a href="#header.referer" class="smpl">Referer</a> and <a href="#header.from" class="smpl">From</a>. 3679 3678 </p> 3680 <p id="rfc.section.1 2.1.p.2">Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks3679 <p id="rfc.section.13.1.p.2">Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks 3681 3680 against software that is known to contain security holes. Implementers <em class="bcp14">SHOULD</em> make the <a href="#header.server" class="smpl">Server</a> header field a configurable option. 3682 3681 </p> 3683 <p id="rfc.section.1 2.1.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,3682 <p id="rfc.section.13.1.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, 3684 3683 they <em class="bcp14">SHOULD</em> remove, or replace with sanitized versions, any <a href="p1-messaging.html#header.via" class="smpl">Via</a> fields generated behind the firewall. 3685 3684 </p> 3686 <p id="rfc.section.1 2.1.p.4">The <a href="#header.referer" class="smpl">Referer</a> header field allows reading patterns to be studied and reverse links drawn. Although it can be very useful, its power can3685 <p id="rfc.section.13.1.p.4">The <a href="#header.referer" class="smpl">Referer</a> header field allows reading patterns to be studied and reverse links drawn. Although it can be very useful, its power can 3687 3686 be abused if user details are not separated from the information contained in the Referer. Even when the personal information 3688 3687 has been removed, the Referer header field might indicate a private document's URI whose publication would be inappropriate. 3689 3688 </p> 3690 <p id="rfc.section.1 2.1.p.5">The information sent in the <a href="#header.from" class="smpl">From</a> field might conflict with the user's privacy interests or their site's security policy, and 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.3691 </p> 3692 <p id="rfc.section.1 2.1.p.6">We suggest, though do not require, that a convenient toggle interface be provided for the user to enable or disable the sending3689 <p id="rfc.section.13.1.p.5">The information sent in the <a href="#header.from" class="smpl">From</a> field might conflict with the user's privacy interests or their site's security policy, and 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. 3690 </p> 3691 <p id="rfc.section.13.1.p.6">We suggest, though do not require, that a convenient toggle interface be provided for the user to enable or disable the sending 3693 3692 of <a href="#header.from" class="smpl">From</a> and <a href="#header.referer" class="smpl">Referer</a> information. 3694 3693 </p> 3695 <p id="rfc.section.1 2.1.p.7">The <a href="#header.user-agent" class="smpl">User-Agent</a> (<a href="#header.user-agent" id="rfc.xref.header.user-agent.4" title="User-Agent">Section 10.18</a>) or <a href="#header.server" class="smpl">Server</a> (<a href="#header.server" id="rfc.xref.header.server.3" title="Server">Section 10.17</a>) header fields can sometimes be used to determine that a specific client or server has a particular security hole which might3694 <p id="rfc.section.13.1.p.7">The <a href="#header.user-agent" class="smpl">User-Agent</a> (<a href="#header.user-agent" id="rfc.xref.header.user-agent.4" title="User-Agent">Section 11.18</a>) or <a href="#header.server" class="smpl">Server</a> (<a href="#header.server" id="rfc.xref.header.server.3" title="Server">Section 11.17</a>) header fields can sometimes be used to determine that a specific client or server has a particular security hole which might 3696 3695 be exploited. Unfortunately, this same information is often used for other valuable purposes for which HTTP currently has 3697 3696 no better mechanism. 3698 3697 </p> 3699 <p id="rfc.section.1 2.1.p.8">Furthermore, the <a href="#header.user-agent" class="smpl">User-Agent</a> header field might contain enough entropy to be used, possibly in conjunction with other material, to uniquely identify the3698 <p id="rfc.section.13.1.p.8">Furthermore, the <a href="#header.user-agent" class="smpl">User-Agent</a> header field might contain enough entropy to be used, possibly in conjunction with other material, to uniquely identify the 3700 3699 user. 3701 3700 </p> 3702 <p id="rfc.section.1 2.1.p.9">Some request methods, like TRACE (<a href="#TRACE" id="rfc.xref.TRACE.4" title="TRACE">Section 4.3.8</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 used3701 <p id="rfc.section.13.1.p.9">Some request methods, like TRACE (<a href="#TRACE" id="rfc.xref.TRACE.4" title="TRACE">Section 4.3.8</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 3703 3702 to collect data from the client. 3704 3703 </p> 3705 <h2 id="rfc.section.1 2.2"><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>3706 <p id="rfc.section.1 2.2.p.1">Because the source of a link might be private information or might reveal an otherwise private information source, it is strongly3704 <h2 id="rfc.section.13.2"><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> 3705 <p id="rfc.section.13.2.p.1">Because the source of a link might be private information or might reveal an otherwise private information source, it is strongly 3707 3706 recommended that the user be able to select whether or not the <a href="#header.referer" class="smpl">Referer</a> field is sent. For example, a browser client could have a toggle switch for browsing openly/anonymously, which would respectively 3708 3707 enable/disable the sending of Referer and From information. 3709 3708 </p> 3710 <p id="rfc.section.1 2.2.p.2">Clients <em class="bcp14">SHOULD NOT</em> include a <a href="#header.referer" class="smpl">Referer</a> header field in a (non-secure) HTTP request if the referring page was transferred with a secure protocol.3711 </p> 3712 <p id="rfc.section.1 2.2.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 existing3709 <p id="rfc.section.13.2.p.2">Clients <em class="bcp14">SHOULD NOT</em> include a <a href="#header.referer" class="smpl">Referer</a> header field in a (non-secure) HTTP request if the referring page was transferred with a secure protocol. 3710 </p> 3711 <p id="rfc.section.13.2.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 3713 3712 servers, proxies, and user agents log or display the request-target in places where it might be visible to third parties. 3714 3713 Such services can use POST-based form submission instead. 3715 3714 </p> 3716 <h2 id="rfc.section.1 2.3"><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>3717 <p id="rfc.section.1 2.3.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 <a href="#header.location" class="smpl">Location</a> and <a href="#header.content-location" class="smpl">Content-Location</a> header fields in responses that are generated under control of said organizations to make sure that they do not attempt to3715 <h2 id="rfc.section.13.3"><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> 3716 <p id="rfc.section.13.3.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 <a href="#header.location" class="smpl">Location</a> and <a href="#header.content-location" class="smpl">Content-Location</a> header fields in responses that are generated under control of said organizations to make sure that they do not attempt to 3718 3717 invalidate resources over which they have no authority. 3719 3718 </p> 3720 <p id="rfc.section.1 2.3.p.2">Furthermore, appending the fragment identifier from one URI to another one obtained from a <a href="#header.location" class="smpl">Location</a> header field might leak confidential information to the target server — although the fragment identifier is not transmitted3719 <p id="rfc.section.13.3.p.2">Furthermore, appending the fragment identifier from one URI to another one obtained from a <a href="#header.location" class="smpl">Location</a> header field might leak confidential information to the target server — although the fragment identifier is not transmitted 3721 3720 in the final request, it might be visible to the user agent through other means, such as scripting. 3722 3721 </p> 3723 <h2 id="rfc.section.1 2.4"><a href="#rfc.section.12.4">12.4</a> Security Considerations for CONNECT3722 <h2 id="rfc.section.13.4"><a href="#rfc.section.13.4">13.4</a> Security Considerations for CONNECT 3724 3723 </h2> 3725 <p id="rfc.section.1 2.4.p.1">Since tunneled data is opaque to the proxy, there are additional risks to tunneling to other well-known or reserved ports.3724 <p id="rfc.section.13.4.p.1">Since tunneled data is opaque to the proxy, there are additional risks to tunneling to other well-known or reserved ports. 3726 3725 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. 3727 3726 </p> 3728 <h2 id="rfc.section.1 2.5"><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>3729 <p id="rfc.section.1 2.5.p.1">Accept header fields can reveal information about the user to all servers which are accessed. The <a href="#header.accept-language" class="smpl">Accept-Language</a> header field in particular can reveal information the user would consider to be of a private nature, because the understanding3727 <h2 id="rfc.section.13.5"><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> 3728 <p id="rfc.section.13.5.p.1">Accept header fields can reveal information about the user to all servers which are accessed. The <a href="#header.accept-language" class="smpl">Accept-Language</a> header field in particular can reveal information the user would consider to be of a private nature, because the understanding 3730 3729 of particular languages is often strongly correlated to the membership of a particular ethnic group. User agents which offer 3731 3730 the option to configure the contents of an Accept-Language header field to be sent in every request are strongly encouraged 3732 3731 to let the configuration process include a message which makes the user aware of the loss of privacy involved. 3733 3732 </p> 3734 <p id="rfc.section.1 2.5.p.2">An approach that limits the loss of privacy would be for a user agent to omit the sending of Accept-Language header fields3733 <p id="rfc.section.13.5.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 3735 3734 by default, and to ask the user whether or not to start sending Accept-Language header fields to a server if it detects, by 3736 3735 looking for any <a href="p6-cache.html#header.vary" class="smpl">Vary</a> header fields generated by the server, that such sending could improve the quality of service. 3737 3736 </p> 3738 <p id="rfc.section.1 2.5.p.3">Elaborate user-customized accept header fields sent in every request, in particular if these include quality values, can be3737 <p id="rfc.section.13.5.p.3">Elaborate user-customized accept header fields sent in every request, in particular if these include quality values, can be 3739 3738 used by servers as relatively reliable and long-lived user identifiers. Such user identifiers would allow content providers 3740 3739 to do click-trail tracking, and would allow collaborating content providers to match cross-server click-trails or form submissions … … 3745 3744 field configurability <em class="bcp14">SHOULD</em> warn users about the loss of privacy which can be involved. 3746 3745 </p> 3747 <h1 id="rfc.section.1 3"><a href="#rfc.section.13">13.</a> <a id="acks" href="#acks">Acknowledgments</a></h1>3748 <p id="rfc.section.1 3.p.1">See <a href="p1-messaging.html#acks" title="Acknowledgments">Section 9</a> of <a href="#Part1" id="rfc.xref.Part1.45"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>.3749 </p> 3750 <h1 id="rfc.references"><a id="rfc.section.1 4" href="#rfc.section.14">14.</a> References3746 <h1 id="rfc.section.14"><a href="#rfc.section.14">14.</a> <a id="acks" href="#acks">Acknowledgments</a></h1> 3747 <p id="rfc.section.14.p.1">See <a href="p1-messaging.html#acks" title="Acknowledgments">Section 9</a> of <a href="#Part1" id="rfc.xref.Part1.45"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>. 3748 </p> 3749 <h1 id="rfc.references"><a id="rfc.section.15" href="#rfc.section.15">15.</a> References 3751 3750 </h1> 3752 <h2 id="rfc.references.1"><a href="#rfc.section.1 4.1" id="rfc.section.14.1">14.1</a> Normative References3751 <h2 id="rfc.references.1"><a href="#rfc.section.15.1" id="rfc.section.15.1">15.1</a> Normative References 3753 3752 </h2> 3754 3753 <table> … … 3829 3828 </tr> 3830 3829 </table> 3831 <h2 id="rfc.references.2"><a href="#rfc.section.1 4.2" id="rfc.section.14.2">14.2</a> Informative References3830 <h2 id="rfc.references.2"><a href="#rfc.section.15.2" id="rfc.section.15.2">15.2</a> Informative References 3832 3831 </h2> 3833 3832 <table> … … 3977 3976 </p> 3978 3977 <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> 3979 <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 7.5.1</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 line3978 <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 8.5.1</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 3980 3979 break sequences. HTTP allows CRLF, bare CR, and bare LF to indicate a line break within text content when a message is transmitted 3981 3980 over HTTP. 3982 3981 </p> 3983 <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 7.5.1</a> of this document to the RFC 2049 canonical form of CRLF. Note, however, that this might be complicated by the presence of3982 <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 8.5.1</a> of this document to the RFC 2049 canonical form of CRLF. Note, however, that this might be complicated by the presence of 3984 3983 a <a href="#header.content-encoding" class="smpl">Content-Encoding</a> and by the fact that HTTP allows the use of some character encodings which do not use octets 13 and 10 to represent CR and 3985 3984 LF, respectively, as is the case for some multi-byte character encodings. … … 3989 3988 </p> 3990 3989 <h2 id="rfc.section.A.3"><a href="#rfc.section.A.3">A.3</a> <a id="conversion.of.date.formats" href="#conversion.of.date.formats">Conversion of Date Formats</a></h2> 3991 <p id="rfc.section.A.3.p.1">HTTP/1.1 uses a restricted set of date formats (<a href="#http.date" title="Date/Time Formats">Section 7.1</a>) to simplify the process of date comparison. Proxies and gateways from other protocols <em class="bcp14">SHOULD</em> ensure that any <a href="#header.date" class="smpl">Date</a> header field present in a message conforms to one of the HTTP/1.1 formats and rewrite the date if necessary.3990 <p id="rfc.section.A.3.p.1">HTTP/1.1 uses a restricted set of date formats (<a href="#http.date" title="Date/Time Formats">Section 8.1</a>) to simplify the process of date comparison. Proxies and gateways from other protocols <em class="bcp14">SHOULD</em> ensure that any <a href="#header.date" class="smpl">Date</a> header field present in a message conforms to one of the HTTP/1.1 formats and rewrite the date if necessary. 3992 3991 </p> 3993 3992 <h2 id="rfc.section.A.4"><a href="#rfc.section.A.4">A.4</a> <a id="introduction.of.content-encoding" href="#introduction.of.content-encoding">Introduction of Content-Encoding</a></h2> … … 4009 4008 <p id="rfc.section.A.6.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 4010 4009 fold long lines. MHTML messages being transported by HTTP follow all conventions of MHTML, including line length limitations 4011 and folding, canonicalization, etc., since HTTP transports all message-bodies as payload (see <a href="#multipart.types" title="Multipart Types">Section 7.5.2</a>) and does not interpret the content or any MIME header lines that might be contained therein.4010 and folding, canonicalization, etc., since HTTP transports all message-bodies as payload (see <a href="#multipart.types" title="Multipart Types">Section 8.5.2</a>) and does not interpret the content or any MIME header lines that might be contained therein. 4012 4011 </p> 4013 4012 <h1 id="rfc.section.B"><a href="#rfc.section.B">B.</a> <a id="additional.features" href="#additional.features">Additional Features</a></h1> … … 4020 4019 </p> 4021 4020 <h1 id="rfc.section.C"><a href="#rfc.section.C">C.</a> <a id="changes.from.rfc.2616" href="#changes.from.rfc.2616">Changes from RFC 2616</a></h1> 4022 <p id="rfc.section.C.p.1">Introduce Method Registry. (<a href="#method.registry" title="Method Registry">Section 1 1.1</a>)4021 <p id="rfc.section.C.p.1">Introduce Method Registry. (<a href="#method.registry" title="Method Registry">Section 12.1</a>) 4023 4022 </p> 4024 4023 <p id="rfc.section.C.p.2">Clarify definition of POST. (<a href="#POST" id="rfc.xref.POST.3" title="POST">Section 4.3.3</a>) … … 4028 4027 <p id="rfc.section.C.p.4">Take over definition of CONNECT method from <a href="#RFC2817" id="rfc.xref.RFC2817.2"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>. (<a href="#CONNECT" id="rfc.xref.CONNECT.3" title="CONNECT">Section 4.3.6</a>) 4029 4028 </p> 4030 <p id="rfc.section.C.p.5">Take over the Status Code Registry, 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.RFC2817.3"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>. (<a href="#status.code.registry" title="Status Code Registry">Section 1 1.2</a>)4029 <p id="rfc.section.C.p.5">Take over the Status Code Registry, 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.RFC2817.3"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>. (<a href="#status.code.registry" title="Status Code Registry">Section 12.2</a>) 4031 4030 </p> 4032 4031 <p id="rfc.section.C.p.6">Broadened the definition of <a href="#status.203" class="smpl">203 (Non-Authoritative Information)</a> to include cases of payload transformations as well. (<a href="#status.203" id="rfc.xref.status.203.3" title="203 Non-Authoritative Information">Section 6.3.4</a>) … … 4044 4043 <p id="rfc.section.C.p.10">Define status <a href="#status.426" class="smpl">426 (Upgrade Required)</a> (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 6.5.15</a>) 4045 4044 </p> 4046 <p id="rfc.section.C.p.11">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section 1 0</a>)4045 <p id="rfc.section.C.p.11">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section 11</a>) 4047 4046 </p> 4048 4047 <p id="rfc.section.C.p.12">Reclassify "<a href="#header.allow" class="smpl">Allow</a>" as response header field, removing the option to specify it in a PUT request. Relax the server requirement on the contents 4049 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 0.5</a>)4048 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 11.5</a>) 4050 4049 </p> 4051 4050 <p id="rfc.section.C.p.13">The ABNF for the <a href="#header.expect" class="smpl">Expect</a> header field has been both fixed (allowing parameters for value-less expectations as well) and simplified (allowing trailing 4052 semicolons after "100-continue" when they were invalid before). (<a href="#header.expect" id="rfc.xref.header.expect.4" title="Expect">Section 1 0.11</a>)4051 semicolons after "100-continue" when they were invalid before). (<a href="#header.expect" id="rfc.xref.header.expect.4" title="Expect">Section 11.11</a>) 4053 4052 </p> 4054 4053 <p id="rfc.section.C.p.14">Correct syntax of <a href="#header.location" class="smpl">Location</a> header field to allow URI references (including relative references and fragments), as referred symbol "absoluteURI" wasn't 4055 what was expected, and add some clarifications as to when use of fragments would not be appropriate. (<a href="#header.location" id="rfc.xref.header.location.5" title="Location">Section 1 0.13</a>)4056 </p> 4057 <p id="rfc.section.C.p.15">Restrict <a href="#header.max-forwards" class="smpl">Max-Forwards</a> 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 0.14</a>)4058 </p> 4059 <p id="rfc.section.C.p.16">Allow <a href="#header.referer" class="smpl">Referer</a> 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 0.15</a>)4060 </p> 4061 <p id="rfc.section.C.p.17">In the description of the <a href="#header.server" class="smpl">Server</a> header field, the <a href="p1-messaging.html#header.via" class="smpl">Via</a> field was described as a SHOULD. The requirement was and is stated correctly in the description of the Via header field in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.46"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>. (<a href="#header.server" id="rfc.xref.header.server.4" title="Server">Section 1 0.17</a>)4062 </p> 4063 <p id="rfc.section.C.p.18">Clarify contexts that charset is used in. (<a href="#character.sets" title="Character Encodings (charset)">Section 7.3</a>)4064 </p> 4065 <p id="rfc.section.C.p.19">Registration of Content Codings now requires IETF Review (<a href="#content.coding.registry" title="Content Coding Registry">Section 1 1.4</a>)4054 what was expected, and add some clarifications as to when use of fragments would not be appropriate. (<a href="#header.location" id="rfc.xref.header.location.5" title="Location">Section 11.13</a>) 4055 </p> 4056 <p id="rfc.section.C.p.15">Restrict <a href="#header.max-forwards" class="smpl">Max-Forwards</a> 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 11.14</a>) 4057 </p> 4058 <p id="rfc.section.C.p.16">Allow <a href="#header.referer" class="smpl">Referer</a> field value of "about:blank" as alternative to not specifying it. (<a href="#header.referer" id="rfc.xref.header.referer.3" title="Referer">Section 11.15</a>) 4059 </p> 4060 <p id="rfc.section.C.p.17">In the description of the <a href="#header.server" class="smpl">Server</a> header field, the <a href="p1-messaging.html#header.via" class="smpl">Via</a> field was described as a SHOULD. The requirement was and is stated correctly in the description of the Via header field in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.46"><cite title="HTTP/1.1, part 1: Message Routing and Syntax"">[Part1]</cite></a>. (<a href="#header.server" id="rfc.xref.header.server.4" title="Server">Section 11.17</a>) 4061 </p> 4062 <p id="rfc.section.C.p.18">Clarify contexts that charset is used in. (<a href="#character.sets" title="Character Encodings (charset)">Section 8.3</a>) 4063 </p> 4064 <p id="rfc.section.C.p.19">Registration of Content Codings now requires IETF Review (<a href="#content.coding.registry" title="Content Coding Registry">Section 12.4</a>) 4066 4065 </p> 4067 4066 <p id="rfc.section.C.p.20">Remove the default character encoding of "ISO-8859-1" for text media types; the default now is whatever the media type definition 4068 says. (<a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 7.5.1</a>)4069 </p> 4070 <p id="rfc.section.C.p.21">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section 1 0</a>)4067 says. (<a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 8.5.1</a>) 4068 </p> 4069 <p id="rfc.section.C.p.21">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section 11</a>) 4071 4070 </p> 4072 4071 <p id="rfc.section.C.p.22">Remove definition of Content-MD5 header field because it was inconsistently implemented with respect to partial responses, 4073 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 0</a>)4074 </p> 4075 <p id="rfc.section.C.p.23">Remove ISO-8859-1 special-casing in <a href="#header.accept-charset" class="smpl">Accept-Charset</a>. (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.4" title="Accept-Charset">Section 1 0.2</a>)4072 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 11</a>) 4073 </p> 4074 <p id="rfc.section.C.p.23">Remove ISO-8859-1 special-casing in <a href="#header.accept-charset" class="smpl">Accept-Charset</a>. (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.4" title="Accept-Charset">Section 11.2</a>) 4076 4075 </p> 4077 4076 <p id="rfc.section.C.p.24">Remove base URI setting semantics for <a href="#header.content-location" class="smpl">Content-Location</a> due to poor implementation support, which was caused by too many broken servers emitting bogus Content-Location header fields, 4078 and also the potentially undesirable effect of potentially breaking relative links in content-negotiated resources. (<a href="#header.content-location" id="rfc.xref.header.content-location.5" title="Content-Location">Section 1 0.8</a>)4077 and also the potentially undesirable effect of potentially breaking relative links in content-negotiated resources. (<a href="#header.content-location" id="rfc.xref.header.content-location.5" title="Content-Location">Section 11.8</a>) 4079 4078 </p> 4080 4079 <p id="rfc.section.C.p.25">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>) … … 4805 4804 <ul class="ind"> 4806 4805 <li><a id="rfc.index.1" href="#rfc.index.1"><b>1</b></a><ul> 4807 <li>100 Continue (status code) <a href="#rfc.xref.status.100.1">6.1</a>, <a href="#rfc.iref.24"><b>6.2.1</b></a>, <a href="#rfc.xref.status.100.2">1 1.2.3</a></li>4808 <li>100-continue (expect value) <a href="#rfc.iref.142"><b>1 0.11</b></a></li>4809 <li>101 Switching Protocols (status code) <a href="#rfc.xref.status.101.1">6.1</a>, <a href="#rfc.iref.25"><b>6.2.2</b></a>, <a href="#rfc.xref.status.101.2">1 1.2.3</a></li>4806 <li>100 Continue (status code) <a href="#rfc.xref.status.100.1">6.1</a>, <a href="#rfc.iref.24"><b>6.2.1</b></a>, <a href="#rfc.xref.status.100.2">12.2.3</a></li> 4807 <li>100-continue (expect value) <a href="#rfc.iref.142"><b>11.11</b></a></li> 4808 <li>101 Switching Protocols (status code) <a href="#rfc.xref.status.101.1">6.1</a>, <a href="#rfc.iref.25"><b>6.2.2</b></a>, <a href="#rfc.xref.status.101.2">12.2.3</a></li> 4810 4809 <li>1xx Informational (status code class) <a href="#rfc.iref.23"><b>6.2</b></a></li> 4811 4810 </ul> 4812 4811 </li> 4813 4812 <li><a id="rfc.index.2" href="#rfc.index.2"><b>2</b></a><ul> 4814 <li>200 OK (status code) <a href="#rfc.xref.status.200.1">6.1</a>, <a href="#rfc.iref.27"><b>6.3.1</b></a>, <a href="#rfc.xref.status.200.2">1 1.2.3</a></li>4815 <li>201 Created (status code) <a href="#rfc.xref.status.201.1">6.1</a>, <a href="#rfc.iref.28"><b>6.3.2</b></a>, <a href="#rfc.xref.status.201.2">1 1.2.3</a></li>4816 <li>202 Accepted (status code) <a href="#rfc.xref.status.202.1">6.1</a>, <a href="#rfc.iref.29"><b>6.3.3</b></a>, <a href="#rfc.xref.status.202.2">1 1.2.3</a></li>4817 <li>203 Non-Authoritative Information (status code) <a href="#rfc.xref.status.203.1">6.1</a>, <a href="#rfc.iref.30"><b>6.3.4</b></a>, <a href="#rfc.xref.status.203.2">1 1.2.3</a>, <a href="#rfc.xref.status.203.3">C</a></li>4818 <li>204 No Content (status code) <a href="#rfc.xref.status.204.1">6.1</a>, <a href="#rfc.iref.31"><b>6.3.5</b></a>, <a href="#rfc.xref.status.204.2">1 1.2.3</a></li>4819 <li>205 Reset Content (status code) <a href="#rfc.xref.status.205.1">6.1</a>, <a href="#rfc.iref.32"><b>6.3.6</b></a>, <a href="#rfc.xref.status.205.2">1 1.2.3</a></li>4813 <li>200 OK (status code) <a href="#rfc.xref.status.200.1">6.1</a>, <a href="#rfc.iref.27"><b>6.3.1</b></a>, <a href="#rfc.xref.status.200.2">12.2.3</a></li> 4814 <li>201 Created (status code) <a href="#rfc.xref.status.201.1">6.1</a>, <a href="#rfc.iref.28"><b>6.3.2</b></a>, <a href="#rfc.xref.status.201.2">12.2.3</a></li> 4815 <li>202 Accepted (status code) <a href="#rfc.xref.status.202.1">6.1</a>, <a href="#rfc.iref.29"><b>6.3.3</b></a>, <a href="#rfc.xref.status.202.2">12.2.3</a></li> 4816 <li>203 Non-Authoritative Information (status code) <a href="#rfc.xref.status.203.1">6.1</a>, <a href="#rfc.iref.30"><b>6.3.4</b></a>, <a href="#rfc.xref.status.203.2">12.2.3</a>, <a href="#rfc.xref.status.203.3">C</a></li> 4817 <li>204 No Content (status code) <a href="#rfc.xref.status.204.1">6.1</a>, <a href="#rfc.iref.31"><b>6.3.5</b></a>, <a href="#rfc.xref.status.204.2">12.2.3</a></li> 4818 <li>205 Reset Content (status code) <a href="#rfc.xref.status.205.1">6.1</a>, <a href="#rfc.iref.32"><b>6.3.6</b></a>, <a href="#rfc.xref.status.205.2">12.2.3</a></li> 4820 4819 <li>2xx Successful (status code class) <a href="#rfc.iref.26"><b>6.3</b></a></li> 4821 4820 </ul> 4822 4821 </li> 4823 4822 <li><a id="rfc.index.3" href="#rfc.index.3"><b>3</b></a><ul> 4824 <li>300 Multiple Choices (status code) <a href="#rfc.xref.status.300.1">6.1</a>, <a href="#rfc.iref.34"><b>6.4.1</b></a>, <a href="#rfc.xref.status.300.2">1 1.2.3</a></li>4825 <li>301 Moved Permanently (status code) <a href="#rfc.xref.status.301.1">6.1</a>, <a href="#rfc.iref.35"><b>6.4.2</b></a>, <a href="#rfc.xref.status.301.2">1 1.2.3</a>, <a href="#rfc.xref.status.301.3">C</a></li>4826 <li>302 Found (status code) <a href="#rfc.xref.status.302.1">6.1</a>, <a href="#rfc.iref.36"><b>6.4.3</b></a>, <a href="#rfc.xref.status.302.2">1 1.2.3</a>, <a href="#rfc.xref.status.302.3">C</a></li>4827 <li>303 See Other (status code) <a href="#rfc.xref.status.303.1">6.1</a>, <a href="#rfc.iref.37"><b>6.4.4</b></a>, <a href="#rfc.xref.status.303.2">1 1.2.3</a></li>4828 <li>305 Use Proxy (status code) <a href="#rfc.xref.status.305.1">6.1</a>, <a href="#rfc.iref.38"><b>6.4.5</b></a>, <a href="#rfc.xref.status.305.2">1 1.2.3</a>, <a href="#rfc.xref.status.305.3">C</a></li>4829 <li>306 (Unused) (status code) <a href="#rfc.iref.39"><b>6.4.6</b></a>, <a href="#rfc.xref.status.306.1">1 1.2.3</a></li>4830 <li>307 Temporary Redirect (status code) <a href="#rfc.xref.status.307.1">6.1</a>, <a href="#rfc.iref.40"><b>6.4.7</b></a>, <a href="#rfc.xref.status.307.2">1 1.2.3</a>, <a href="#rfc.xref.status.307.3">C</a></li>4823 <li>300 Multiple Choices (status code) <a href="#rfc.xref.status.300.1">6.1</a>, <a href="#rfc.iref.34"><b>6.4.1</b></a>, <a href="#rfc.xref.status.300.2">12.2.3</a></li> 4824 <li>301 Moved Permanently (status code) <a href="#rfc.xref.status.301.1">6.1</a>, <a href="#rfc.iref.35"><b>6.4.2</b></a>, <a href="#rfc.xref.status.301.2">12.2.3</a>, <a href="#rfc.xref.status.301.3">C</a></li> 4825 <li>302 Found (status code) <a href="#rfc.xref.status.302.1">6.1</a>, <a href="#rfc.iref.36"><b>6.4.3</b></a>, <a href="#rfc.xref.status.302.2">12.2.3</a>, <a href="#rfc.xref.status.302.3">C</a></li> 4826 <li>303 See Other (status code) <a href="#rfc.xref.status.303.1">6.1</a>, <a href="#rfc.iref.37"><b>6.4.4</b></a>, <a href="#rfc.xref.status.303.2">12.2.3</a></li> 4827 <li>305 Use Proxy (status code) <a href="#rfc.xref.status.305.1">6.1</a>, <a href="#rfc.iref.38"><b>6.4.5</b></a>, <a href="#rfc.xref.status.305.2">12.2.3</a>, <a href="#rfc.xref.status.305.3">C</a></li> 4828 <li>306 (Unused) (status code) <a href="#rfc.iref.39"><b>6.4.6</b></a>, <a href="#rfc.xref.status.306.1">12.2.3</a></li> 4829 <li>307 Temporary Redirect (status code) <a href="#rfc.xref.status.307.1">6.1</a>, <a href="#rfc.iref.40"><b>6.4.7</b></a>, <a href="#rfc.xref.status.307.2">12.2.3</a>, <a href="#rfc.xref.status.307.3">C</a></li> 4831 4830 <li>3xx Redirection (status code class) <a href="#rfc.iref.33"><b>6.4</b></a>, <a href="#rfc.xref.status.3xx.1">C</a></li> 4832 4831 </ul> 4833 4832 </li> 4834 4833 <li><a id="rfc.index.4" href="#rfc.index.4"><b>4</b></a><ul> 4835 <li>400 Bad Request (status code) <a href="#rfc.xref.status.400.1">6.1</a>, <a href="#rfc.iref.42"><b>6.5.1</b></a>, <a href="#rfc.xref.status.400.2">1 1.2.3</a></li>4836 <li>402 Payment Required (status code) <a href="#rfc.xref.status.402.1">6.1</a>, <a href="#rfc.iref.43"><b>6.5.2</b></a>, <a href="#rfc.xref.status.402.2">1 1.2.3</a></li>4837 <li>403 Forbidden (status code) <a href="#rfc.xref.status.403.1">6.1</a>, <a href="#rfc.iref.44"><b>6.5.3</b></a>, <a href="#rfc.xref.status.403.2">1 1.2.3</a></li>4838 <li>404 Not Found (status code) <a href="#rfc.xref.status.404.1">6.1</a>, <a href="#rfc.iref.45"><b>6.5.4</b></a>, <a href="#rfc.xref.status.404.2">1 1.2.3</a></li>4839 <li>405 Method Not Allowed (status code) <a href="#rfc.xref.status.405.1">6.1</a>, <a href="#rfc.iref.46"><b>6.5.5</b></a>, <a href="#rfc.xref.status.405.2">1 1.2.3</a></li>4840 <li>406 Not Acceptable (status code) <a href="#rfc.xref.status.406.1">6.1</a>, <a href="#rfc.iref.47"><b>6.5.6</b></a>, <a href="#rfc.xref.status.406.2">1 1.2.3</a></li>4841 <li>408 Request Timeout (status code) <a href="#rfc.xref.status.408.1">6.1</a>, <a href="#rfc.iref.48"><b>6.5.7</b></a>, <a href="#rfc.xref.status.408.2">1 1.2.3</a></li>4842 <li>409 Conflict (status code) <a href="#rfc.xref.status.409.1">6.1</a>, <a href="#rfc.iref.49"><b>6.5.8</b></a>, <a href="#rfc.xref.status.409.2">1 1.2.3</a></li>4843 <li>410 Gone (status code) <a href="#rfc.xref.status.410.1">6.1</a>, <a href="#rfc.iref.50"><b>6.5.9</b></a>, <a href="#rfc.xref.status.410.2">1 1.2.3</a></li>4844 <li>411 Length Required (status code) <a href="#rfc.xref.status.411.1">6.1</a>, <a href="#rfc.iref.51"><b>6.5.10</b></a>, <a href="#rfc.xref.status.411.2">1 1.2.3</a></li>4845 <li>413 Request Representation Too Large (status code) <a href="#rfc.xref.status.413.1">6.1</a>, <a href="#rfc.iref.52"><b>6.5.11</b></a>, <a href="#rfc.xref.status.413.2">1 1.2.3</a></li>4846 <li>414 URI Too Long (status code) <a href="#rfc.xref.status.414.1">6.1</a>, <a href="#rfc.iref.53"><b>6.5.12</b></a>, <a href="#rfc.xref.status.414.2">1 1.2.3</a></li>4847 <li>415 Unsupported Media Type (status code) <a href="#rfc.xref.status.415.1">6.1</a>, <a href="#rfc.iref.54"><b>6.5.13</b></a>, <a href="#rfc.xref.status.415.2">1 1.2.3</a></li>4848 <li>417 Expectation Failed (status code) <a href="#rfc.xref.status.417.1">6.1</a>, <a href="#rfc.iref.55"><b>6.5.14</b></a>, <a href="#rfc.xref.status.417.2">1 1.2.3</a></li>4849 <li>426 Upgrade Required (status code) <a href="#rfc.xref.status.426.1">6.1</a>, <a href="#rfc.iref.56"><b>6.5.15</b></a>, <a href="#rfc.xref.status.426.2">1 1.2.3</a>, <a href="#rfc.xref.status.426.3">C</a></li>4834 <li>400 Bad Request (status code) <a href="#rfc.xref.status.400.1">6.1</a>, <a href="#rfc.iref.42"><b>6.5.1</b></a>, <a href="#rfc.xref.status.400.2">12.2.3</a></li> 4835 <li>402 Payment Required (status code) <a href="#rfc.xref.status.402.1">6.1</a>, <a href="#rfc.iref.43"><b>6.5.2</b></a>, <a href="#rfc.xref.status.402.2">12.2.3</a></li> 4836 <li>403 Forbidden (status code) <a href="#rfc.xref.status.403.1">6.1</a>, <a href="#rfc.iref.44"><b>6.5.3</b></a>, <a href="#rfc.xref.status.403.2">12.2.3</a></li> 4837 <li>404 Not Found (status code) <a href="#rfc.xref.status.404.1">6.1</a>, <a href="#rfc.iref.45"><b>6.5.4</b></a>, <a href="#rfc.xref.status.404.2">12.2.3</a></li> 4838 <li>405 Method Not Allowed (status code) <a href="#rfc.xref.status.405.1">6.1</a>, <a href="#rfc.iref.46"><b>6.5.5</b></a>, <a href="#rfc.xref.status.405.2">12.2.3</a></li> 4839 <li>406 Not Acceptable (status code) <a href="#rfc.xref.status.406.1">6.1</a>, <a href="#rfc.iref.47"><b>6.5.6</b></a>, <a href="#rfc.xref.status.406.2">12.2.3</a></li> 4840 <li>408 Request Timeout (status code) <a href="#rfc.xref.status.408.1">6.1</a>, <a href="#rfc.iref.48"><b>6.5.7</b></a>, <a href="#rfc.xref.status.408.2">12.2.3</a></li> 4841 <li>409 Conflict (status code) <a href="#rfc.xref.status.409.1">6.1</a>, <a href="#rfc.iref.49"><b>6.5.8</b></a>, <a href="#rfc.xref.status.409.2">12.2.3</a></li> 4842 <li>410 Gone (status code) <a href="#rfc.xref.status.410.1">6.1</a>, <a href="#rfc.iref.50"><b>6.5.9</b></a>, <a href="#rfc.xref.status.410.2">12.2.3</a></li> 4843 <li>411 Length Required (status code) <a href="#rfc.xref.status.411.1">6.1</a>, <a href="#rfc.iref.51"><b>6.5.10</b></a>, <a href="#rfc.xref.status.411.2">12.2.3</a></li> 4844 <li>413 Request Representation Too Large (status code) <a href="#rfc.xref.status.413.1">6.1</a>, <a href="#rfc.iref.52"><b>6.5.11</b></a>, <a href="#rfc.xref.status.413.2">12.2.3</a></li> 4845 <li>414 URI Too Long (status code) <a href="#rfc.xref.status.414.1">6.1</a>, <a href="#rfc.iref.53"><b>6.5.12</b></a>, <a href="#rfc.xref.status.414.2">12.2.3</a></li> 4846 <li>415 Unsupported Media Type (status code) <a href="#rfc.xref.status.415.1">6.1</a>, <a href="#rfc.iref.54"><b>6.5.13</b></a>, <a href="#rfc.xref.status.415.2">12.2.3</a></li> 4847 <li>417 Expectation Failed (status code) <a href="#rfc.xref.status.417.1">6.1</a>, <a href="#rfc.iref.55"><b>6.5.14</b></a>, <a href="#rfc.xref.status.417.2">12.2.3</a></li> 4848 <li>426 Upgrade Required (status code) <a href="#rfc.xref.status.426.1">6.1</a>, <a href="#rfc.iref.56"><b>6.5.15</b></a>, <a href="#rfc.xref.status.426.2">12.2.3</a>, <a href="#rfc.xref.status.426.3">C</a></li> 4850 4849 <li>4xx Client Error (status code class) <a href="#rfc.iref.41"><b>6.5</b></a></li> 4851 4850 </ul> 4852 4851 </li> 4853 4852 <li><a id="rfc.index.5" href="#rfc.index.5"><b>5</b></a><ul> 4854 <li>500 Internal Server Error (status code) <a href="#rfc.xref.status.500.1">6.1</a>, <a href="#rfc.iref.58"><b>6.6.1</b></a>, <a href="#rfc.xref.status.500.2">1 1.2.3</a></li>4855 <li>501 Not Implemented (status code) <a href="#rfc.xref.status.501.1">6.1</a>, <a href="#rfc.iref.59"><b>6.6.2</b></a>, <a href="#rfc.xref.status.501.2">1 1.2.3</a></li>4856 <li>502 Bad Gateway (status code) <a href="#rfc.xref.status.502.1">6.1</a>, <a href="#rfc.iref.60"><b>6.6.3</b></a>, <a href="#rfc.xref.status.502.2">1 1.2.3</a></li>4857 <li>503 Service Unavailable (status code) <a href="#rfc.xref.status.503.1">6.1</a>, <a href="#rfc.iref.61"><b>6.6.4</b></a>, <a href="#rfc.xref.status.503.2">1 1.2.3</a></li>4858 <li>504 Gateway Timeout (status code) <a href="#rfc.xref.status.504.1">6.1</a>, <a href="#rfc.iref.62"><b>6.6.5</b></a>, <a href="#rfc.xref.status.504.2">1 1.2.3</a></li>4859 <li>505 HTTP Version Not Supported (status code) <a href="#rfc.xref.status.505.1">6.1</a>, <a href="#rfc.iref.63"><b>6.6.6</b></a>, <a href="#rfc.xref.status.505.2">1 1.2.3</a></li>4853 <li>500 Internal Server Error (status code) <a href="#rfc.xref.status.500.1">6.1</a>, <a href="#rfc.iref.58"><b>6.6.1</b></a>, <a href="#rfc.xref.status.500.2">12.2.3</a></li> 4854 <li>501 Not Implemented (status code) <a href="#rfc.xref.status.501.1">6.1</a>, <a href="#rfc.iref.59"><b>6.6.2</b></a>, <a href="#rfc.xref.status.501.2">12.2.3</a></li> 4855 <li>502 Bad Gateway (status code) <a href="#rfc.xref.status.502.1">6.1</a>, <a href="#rfc.iref.60"><b>6.6.3</b></a>, <a href="#rfc.xref.status.502.2">12.2.3</a></li> 4856 <li>503 Service Unavailable (status code) <a href="#rfc.xref.status.503.1">6.1</a>, <a href="#rfc.iref.61"><b>6.6.4</b></a>, <a href="#rfc.xref.status.503.2">12.2.3</a></li> 4857 <li>504 Gateway Timeout (status code) <a href="#rfc.xref.status.504.1">6.1</a>, <a href="#rfc.iref.62"><b>6.6.5</b></a>, <a href="#rfc.xref.status.504.2">12.2.3</a></li> 4858 <li>505 HTTP Version Not Supported (status code) <a href="#rfc.xref.status.505.1">6.1</a>, <a href="#rfc.iref.63"><b>6.6.6</b></a>, <a href="#rfc.xref.status.505.2">12.2.3</a></li> 4860 4859 <li>5xx Server Error (status code class) <a href="#rfc.iref.57"><b>6.6</b></a></li> 4861 4860 </ul> 4862 4861 </li> 4863 4862 <li><a id="rfc.index.A" href="#rfc.index.A"><b>A</b></a><ul> 4864 <li>Accept header field <a href="#rfc.xref.header.accept.1">5 .5</a>, <a href="#rfc.xref.header.accept.2">7.5</a>, <a href="#rfc.xref.header.accept.3">9.1</a>, <a href="#rfc.iref.a.1"><b>10.1</b></a>, <a href="#rfc.xref.header.accept.4">11.3.2</a></li>4865 <li>Accept-Charset header field <a href="#rfc.xref.header.accept-charset.1">5 .5</a>, <a href="#rfc.xref.header.accept-charset.2">9.1</a>, <a href="#rfc.iref.a.2"><b>10.2</b></a>, <a href="#rfc.xref.header.accept-charset.3">11.3.2</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li>4866 <li>Accept-Encoding header field <a href="#rfc.xref.header.accept-encoding.1">5 .5</a>, <a href="#rfc.xref.header.accept-encoding.2">7.4</a>, <a href="#rfc.xref.header.accept-encoding.3">9.1</a>, <a href="#rfc.iref.a.3"><b>10.3</b></a>, <a href="#rfc.xref.header.accept-encoding.4">11.3.2</a>, <a href="#rfc.xref.header.accept-encoding.5">11.4.2</a></li>4867 <li>Accept-Language header field <a href="#rfc.xref.header.accept-language.1">5 .5</a>, <a href="#rfc.xref.header.accept-language.2">9.1</a>, <a href="#rfc.iref.a.4"><b>10.4</b></a>, <a href="#rfc.xref.header.accept-language.3">11.3.2</a></li>4868 <li>Allow header field <a href="#rfc.xref.header.allow.1">4.1</a>, <a href="#rfc.xref.header.allow.2"> 5.6</a>, <a href="#rfc.iref.a.5"><b>10.5</b></a>, <a href="#rfc.xref.header.allow.3">11.3.2</a>, <a href="#rfc.xref.header.allow.4">C</a></li>4863 <li>Accept header field <a href="#rfc.xref.header.accept.1">5</a>, <a href="#rfc.xref.header.accept.2">8.5</a>, <a href="#rfc.xref.header.accept.3">10.1</a>, <a href="#rfc.iref.a.1"><b>11.1</b></a>, <a href="#rfc.xref.header.accept.4">12.3.2</a></li> 4864 <li>Accept-Charset header field <a href="#rfc.xref.header.accept-charset.1">5</a>, <a href="#rfc.xref.header.accept-charset.2">10.1</a>, <a href="#rfc.iref.a.2"><b>11.2</b></a>, <a href="#rfc.xref.header.accept-charset.3">12.3.2</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li> 4865 <li>Accept-Encoding header field <a href="#rfc.xref.header.accept-encoding.1">5</a>, <a href="#rfc.xref.header.accept-encoding.2">8.4</a>, <a href="#rfc.xref.header.accept-encoding.3">10.1</a>, <a href="#rfc.iref.a.3"><b>11.3</b></a>, <a href="#rfc.xref.header.accept-encoding.4">12.3.2</a>, <a href="#rfc.xref.header.accept-encoding.5">12.4.2</a></li> 4866 <li>Accept-Language header field <a href="#rfc.xref.header.accept-language.1">5</a>, <a href="#rfc.xref.header.accept-language.2">10.1</a>, <a href="#rfc.iref.a.4"><b>11.4</b></a>, <a href="#rfc.xref.header.accept-language.3">12.3.2</a></li> 4867 <li>Allow header field <a href="#rfc.xref.header.allow.1">4.1</a>, <a href="#rfc.xref.header.allow.2">7</a>, <a href="#rfc.iref.a.5"><b>11.5</b></a>, <a href="#rfc.xref.header.allow.3">12.3.2</a>, <a href="#rfc.xref.header.allow.4">C</a></li> 4869 4868 </ul> 4870 4869 </li> … … 4873 4872 <li>Coding Format 4874 4873 <ul> 4875 <li>compress <a href="#rfc.iref.c.5"> 7.4</a></li>4876 <li>deflate <a href="#rfc.iref.c.6"> 7.4</a></li>4877 <li>gzip <a href="#rfc.iref.c.7"> 7.4</a></li>4874 <li>compress <a href="#rfc.iref.c.5">8.4</a></li> 4875 <li>deflate <a href="#rfc.iref.c.6">8.4</a></li> 4876 <li>gzip <a href="#rfc.iref.c.7">8.4</a></li> 4878 4877 </ul> 4879 4878 </li> 4880 <li>compress (Coding Format) <a href="#rfc.iref.c.4"> 7.4</a></li>4881 <li>CONNECT method <a href="#rfc.xref.CONNECT.1">4.1</a>, <a href="#rfc.iref.c.3"><b>4.3.6</b></a>, <a href="#rfc.xref.CONNECT.2">1 1.1.3</a>, <a href="#rfc.xref.CONNECT.3">C</a></li>4879 <li>compress (Coding Format) <a href="#rfc.iref.c.4">8.4</a></li> 4880 <li>CONNECT method <a href="#rfc.xref.CONNECT.1">4.1</a>, <a href="#rfc.iref.c.3"><b>4.3.6</b></a>, <a href="#rfc.xref.CONNECT.2">12.1.3</a>, <a href="#rfc.xref.CONNECT.3">C</a></li> 4882 4881 <li>content negotiation <a href="#rfc.iref.c.1">1</a></li> 4883 <li>Content-Encoding header field <a href="#rfc.xref.header.content-encoding.1">3.2</a>, <a href="#rfc.xref.header.content-encoding.2"> 7.4</a>, <a href="#rfc.iref.c.8"><b>10.6</b></a>, <a href="#rfc.xref.header.content-encoding.3">11.3.2</a></li>4884 <li>Content-Language header field <a href="#rfc.xref.header.content-language.1">3.2</a>, <a href="#rfc.iref.c.9"><b>1 0.7</b></a>, <a href="#rfc.xref.header.content-language.2">11.3.2</a></li>4885 <li>Content-Location header field <a href="#rfc.xref.header.content-location.1">3.2</a>, <a href="#rfc.xref.header.content-location.2">4.3.3</a>, <a href="#rfc.iref.c.10"><b>1 0.8</b></a>, <a href="#rfc.xref.header.content-location.3">10.13</a>, <a href="#rfc.xref.header.content-location.4">11.3.2</a>, <a href="#rfc.xref.header.content-location.5">C</a></li>4882 <li>Content-Encoding header field <a href="#rfc.xref.header.content-encoding.1">3.2</a>, <a href="#rfc.xref.header.content-encoding.2">8.4</a>, <a href="#rfc.iref.c.8"><b>11.6</b></a>, <a href="#rfc.xref.header.content-encoding.3">12.3.2</a></li> 4883 <li>Content-Language header field <a href="#rfc.xref.header.content-language.1">3.2</a>, <a href="#rfc.iref.c.9"><b>11.7</b></a>, <a href="#rfc.xref.header.content-language.2">12.3.2</a></li> 4884 <li>Content-Location header field <a href="#rfc.xref.header.content-location.1">3.2</a>, <a href="#rfc.xref.header.content-location.2">4.3.3</a>, <a href="#rfc.iref.c.10"><b>11.8</b></a>, <a href="#rfc.xref.header.content-location.3">11.13</a>, <a href="#rfc.xref.header.content-location.4">12.3.2</a>, <a href="#rfc.xref.header.content-location.5">C</a></li> 4886 4885 <li>Content-Transfer-Encoding header field <a href="#rfc.iref.c.12">A.5</a>, <a href="#rfc.xref.no.content-transfer-encoding.1">C</a></li> 4887 <li>Content-Type header field <a href="#rfc.xref.header.content-type.1">3.2</a>, <a href="#rfc.xref.header.content-type.2">6</a>, <a href="#rfc.xref.header.content-type.3"> 7.5</a>, <a href="#rfc.iref.c.11"><b>10.9</b></a>, <a href="#rfc.xref.header.content-type.4">11.3.1</a>, <a href="#rfc.xref.header.content-type.5">11.3.2</a></li>4886 <li>Content-Type header field <a href="#rfc.xref.header.content-type.1">3.2</a>, <a href="#rfc.xref.header.content-type.2">6</a>, <a href="#rfc.xref.header.content-type.3">8.5</a>, <a href="#rfc.iref.c.11"><b>11.9</b></a>, <a href="#rfc.xref.header.content-type.4">12.3.1</a>, <a href="#rfc.xref.header.content-type.5">12.3.2</a></li> 4888 4887 </ul> 4889 4888 </li> 4890 4889 <li><a id="rfc.index.D" href="#rfc.index.D"><b>D</b></a><ul> 4891 <li>Date header field <a href="#rfc.xref.header.date.1"> 5.6</a>, <a href="#rfc.iref.d.3"><b>10.10</b></a>, <a href="#rfc.xref.header.date.2">11.3.2</a></li>4892 <li>deflate (Coding Format) <a href="#rfc.iref.d.2"> 7.4</a></li>4893 <li>DELETE method <a href="#rfc.xref.DELETE.1">4.1</a>, <a href="#rfc.iref.d.1"><b>4.3.5</b></a>, <a href="#rfc.xref.DELETE.2">1 1.1.3</a></li>4890 <li>Date header field <a href="#rfc.xref.header.date.1">7</a>, <a href="#rfc.iref.d.3"><b>11.10</b></a>, <a href="#rfc.xref.header.date.2">12.3.2</a></li> 4891 <li>deflate (Coding Format) <a href="#rfc.iref.d.2">8.4</a></li> 4892 <li>DELETE method <a href="#rfc.xref.DELETE.1">4.1</a>, <a href="#rfc.iref.d.1"><b>4.3.5</b></a>, <a href="#rfc.xref.DELETE.2">12.1.3</a></li> 4894 4893 </ul> 4895 4894 </li> 4896 4895 <li><a id="rfc.index.E" href="#rfc.index.E"><b>E</b></a><ul> 4897 <li>Expect header field <a href="#rfc.xref.header.expect.1">5 .5</a>, <a href="#rfc.xref.header.expect.2">6.5.14</a>, <a href="#rfc.iref.e.1"><b>10.11</b></a>, <a href="#rfc.xref.header.expect.3">11.3.2</a>, <a href="#rfc.xref.header.expect.4">C</a></li>4896 <li>Expect header field <a href="#rfc.xref.header.expect.1">5</a>, <a href="#rfc.xref.header.expect.2">6.5.14</a>, <a href="#rfc.iref.e.1"><b>11.11</b></a>, <a href="#rfc.xref.header.expect.3">12.3.2</a>, <a href="#rfc.xref.header.expect.4">C</a></li> 4898 4897 <li>Expect Values 4899 4898 <ul> 4900 <li>100-continue <a href="#rfc.iref.e.2"><b>1 0.11</b></a></li>4899 <li>100-continue <a href="#rfc.iref.e.2"><b>11.11</b></a></li> 4901 4900 </ul> 4902 4901 </li> … … 4904 4903 </li> 4905 4904 <li><a id="rfc.index.F" href="#rfc.index.F"><b>F</b></a><ul> 4906 <li>From header field <a href="#rfc.xref.header.from.1">5 .5</a>, <a href="#rfc.iref.f.1"><b>10.12</b></a>, <a href="#rfc.xref.header.from.2">11.3.2</a></li>4905 <li>From header field <a href="#rfc.xref.header.from.1">5</a>, <a href="#rfc.iref.f.1"><b>11.12</b></a>, <a href="#rfc.xref.header.from.2">12.3.2</a></li> 4907 4906 </ul> 4908 4907 </li> 4909 4908 <li><a id="rfc.index.G" href="#rfc.index.G"><b>G</b></a><ul> 4910 <li>GET method <a href="#rfc.xref.GET.1">4.1</a>, <a href="#rfc.iref.g.2"><b>4.3.1</b></a>, <a href="#rfc.xref.GET.2">1 1.1.3</a></li>4909 <li>GET method <a href="#rfc.xref.GET.1">4.1</a>, <a href="#rfc.iref.g.2"><b>4.3.1</b></a>, <a href="#rfc.xref.GET.2">12.1.3</a></li> 4911 4910 <li><tt>Grammar</tt> 4912 4911 <ul> 4913 <li><tt>Accept</tt> <a href="#rfc.iref.g.33"><b>1 0.1</b></a></li>4914 <li><tt>Accept-Charset</tt> <a href="#rfc.iref.g.37"><b>1 0.2</b></a></li>4915 <li><tt>Accept-Encoding</tt> <a href="#rfc.iref.g.38"><b>1 0.3</b></a></li>4916 <li><tt>accept-ext</tt> <a href="#rfc.iref.g.36"><b>1 0.1</b></a></li>4917 <li><tt>Accept-Language</tt> <a href="#rfc.iref.g.40"><b>1 0.4</b></a></li>4918 <li><tt>accept-params</tt> <a href="#rfc.iref.g.35"><b>1 0.1</b></a></li>4919 <li><tt>Allow</tt> <a href="#rfc.iref.g.42"><b>1 0.5</b></a></li>4920 <li><tt>asctime-date</tt> <a href="#rfc.iref.g.18"><b> 7.1</b></a></li>4921 <li><tt>attribute</tt> <a href="#rfc.iref.g.28"><b> 7.5</b></a></li>4922 <li><tt>charset</tt> <a href="#rfc.iref.g.21"><b> 7.3</b></a></li>4923 <li><tt>codings</tt> <a href="#rfc.iref.g.39"><b>1 0.3</b></a></li>4924 <li><tt>content-coding</tt> <a href="#rfc.iref.g.22"><b> 7.4</b></a></li>4925 <li><tt>Content-Encoding</tt> <a href="#rfc.iref.g.43"><b>1 0.6</b></a></li>4926 <li><tt>Content-Language</tt> <a href="#rfc.iref.g.44"><b>1 0.7</b></a></li>4927 <li><tt>Content-Location</tt> <a href="#rfc.iref.g.45"><b>1 0.8</b></a></li>4928 <li><tt>Content-Type</tt> <a href="#rfc.iref.g.46"><b>1 0.9</b></a></li>4929 <li><tt>Date</tt> <a href="#rfc.iref.g.47"><b>1 0.10</b></a></li>4930 <li><tt>date1</tt> <a href="#rfc.iref.g.5"><b> 7.1</b></a></li>4931 <li><tt>day</tt> <a href="#rfc.iref.g.12"><b> 7.1</b></a></li>4932 <li><tt>day-name</tt> <a href="#rfc.iref.g.10"><b> 7.1</b></a></li>4933 <li><tt>day-name-l</tt> <a href="#rfc.iref.g.11"><b> 7.1</b></a></li>4934 <li><tt>delta-seconds</tt> <a href="#rfc.iref.g.58"><b>1 0.16</b></a></li>4935 <li><tt>Expect</tt> <a href="#rfc.iref.g.48"><b>1 0.11</b></a></li>4936 <li><tt>expect-name</tt> <a href="#rfc.iref.g.52"><b>1 0.11</b></a></li>4937 <li><tt>expect-param</tt> <a href="#rfc.iref.g.50"><b>1 0.11</b></a></li>4938 <li><tt>expect-value</tt> <a href="#rfc.iref.g.51"><b>1 0.11</b></a></li>4939 <li><tt>expectation</tt> <a href="#rfc.iref.g.49"><b>1 0.11</b></a></li>4940 <li><tt>From</tt> <a href="#rfc.iref.g.53"><b>1 0.12</b></a></li>4941 <li><tt>GMT</tt> <a href="#rfc.iref.g.15"><b> 7.1</b></a></li>4942 <li><tt>hour</tt> <a href="#rfc.iref.g.7"><b> 7.1</b></a></li>4943 <li><tt>HTTP-date</tt> <a href="#rfc.iref.g.3"><b> 7.1</b></a></li>4944 <li><tt>language-range</tt> <a href="#rfc.iref.g.41"><b>1 0.4</b></a></li>4945 <li><tt>language-tag</tt> <a href="#rfc.iref.g.30"><b> 7.6</b></a></li>4946 <li><tt>Location</tt> <a href="#rfc.iref.g.54"><b>1 0.13</b></a></li>4947 <li><tt>Max-Forwards</tt> <a href="#rfc.iref.g.55"><b>1 0.14</b></a></li>4948 <li><tt>media-range</tt> <a href="#rfc.iref.g.34"><b>1 0.1</b></a></li>4949 <li><tt>media-type</tt> <a href="#rfc.iref.g.24"><b> 7.5</b></a></li>4912 <li><tt>Accept</tt> <a href="#rfc.iref.g.33"><b>11.1</b></a></li> 4913 <li><tt>Accept-Charset</tt> <a href="#rfc.iref.g.37"><b>11.2</b></a></li> 4914 <li><tt>Accept-Encoding</tt> <a href="#rfc.iref.g.38"><b>11.3</b></a></li> 4915 <li><tt>accept-ext</tt> <a href="#rfc.iref.g.36"><b>11.1</b></a></li> 4916 <li><tt>Accept-Language</tt> <a href="#rfc.iref.g.40"><b>11.4</b></a></li> 4917 <li><tt>accept-params</tt> <a href="#rfc.iref.g.35"><b>11.1</b></a></li> 4918 <li><tt>Allow</tt> <a href="#rfc.iref.g.42"><b>11.5</b></a></li> 4919 <li><tt>asctime-date</tt> <a href="#rfc.iref.g.18"><b>8.1</b></a></li> 4920 <li><tt>attribute</tt> <a href="#rfc.iref.g.28"><b>8.5</b></a></li> 4921 <li><tt>charset</tt> <a href="#rfc.iref.g.21"><b>8.3</b></a></li> 4922 <li><tt>codings</tt> <a href="#rfc.iref.g.39"><b>11.3</b></a></li> 4923 <li><tt>content-coding</tt> <a href="#rfc.iref.g.22"><b>8.4</b></a></li> 4924 <li><tt>Content-Encoding</tt> <a href="#rfc.iref.g.43"><b>11.6</b></a></li> 4925 <li><tt>Content-Language</tt> <a href="#rfc.iref.g.44"><b>11.7</b></a></li> 4926 <li><tt>Content-Location</tt> <a href="#rfc.iref.g.45"><b>11.8</b></a></li> 4927 <li><tt>Content-Type</tt> <a href="#rfc.iref.g.46"><b>11.9</b></a></li> 4928 <li><tt>Date</tt> <a href="#rfc.iref.g.47"><b>11.10</b></a></li> 4929 <li><tt>date1</tt> <a href="#rfc.iref.g.5"><b>8.1</b></a></li> 4930 <li><tt>day</tt> <a href="#rfc.iref.g.12"><b>8.1</b></a></li> 4931 <li><tt>day-name</tt> <a href="#rfc.iref.g.10"><b>8.1</b></a></li> 4932 <li><tt>day-name-l</tt> <a href="#rfc.iref.g.11"><b>8.1</b></a></li> 4933 <li><tt>delta-seconds</tt> <a href="#rfc.iref.g.58"><b>11.16</b></a></li> 4934 <li><tt>Expect</tt> <a href="#rfc.iref.g.48"><b>11.11</b></a></li> 4935 <li><tt>expect-name</tt> <a href="#rfc.iref.g.52"><b>11.11</b></a></li> 4936 <li><tt>expect-param</tt> <a href="#rfc.iref.g.50"><b>11.11</b></a></li> 4937 <li><tt>expect-value</tt> <a href="#rfc.iref.g.51"><b>11.11</b></a></li> 4938 <li><tt>expectation</tt> <a href="#rfc.iref.g.49"><b>11.11</b></a></li> 4939 <li><tt>From</tt> <a href="#rfc.iref.g.53"><b>11.12</b></a></li> 4940 <li><tt>GMT</tt> <a href="#rfc.iref.g.15"><b>8.1</b></a></li> 4941 <li><tt>hour</tt> <a href="#rfc.iref.g.7"><b>8.1</b></a></li> 4942 <li><tt>HTTP-date</tt> <a href="#rfc.iref.g.3"><b>8.1</b></a></li> 4943 <li><tt>language-range</tt> <a href="#rfc.iref.g.41"><b>11.4</b></a></li> 4944 <li><tt>language-tag</tt> <a href="#rfc.iref.g.30"><b>8.6</b></a></li> 4945 <li><tt>Location</tt> <a href="#rfc.iref.g.54"><b>11.13</b></a></li> 4946 <li><tt>Max-Forwards</tt> <a href="#rfc.iref.g.55"><b>11.14</b></a></li> 4947 <li><tt>media-range</tt> <a href="#rfc.iref.g.34"><b>11.1</b></a></li> 4948 <li><tt>media-type</tt> <a href="#rfc.iref.g.24"><b>8.5</b></a></li> 4950 4949 <li><tt>method</tt> <a href="#rfc.iref.g.1"><b>4.1</b></a></li> 4951 4950 <li><tt>MIME-Version</tt> <a href="#rfc.iref.g.61"><b>A.1</b></a></li> 4952 <li><tt>minute</tt> <a href="#rfc.iref.g.8"><b> 7.1</b></a></li>4953 <li><tt>month</tt> <a href="#rfc.iref.g.13"><b> 7.1</b></a></li>4954 <li><tt>obs-date</tt> <a href="#rfc.iref.g.16"><b> 7.1</b></a></li>4955 <li><tt>parameter</tt> <a href="#rfc.iref.g.27"><b> 7.5</b></a></li>4956 <li><tt>product</tt> <a href="#rfc.iref.g.19"><b> 7.2</b></a></li>4957 <li><tt>product-version</tt> <a href="#rfc.iref.g.20"><b> 7.2</b></a></li>4958 <li><tt>qvalue</tt> <a href="#rfc.iref.g.32"><b> 9.3</b></a></li>4959 <li><tt>Referer</tt> <a href="#rfc.iref.g.56"><b>1 0.15</b></a></li>4960 <li><tt>Retry-After</tt> <a href="#rfc.iref.g.57"><b>1 0.16</b></a></li>4961 <li><tt>rfc1123-date</tt> <a href="#rfc.iref.g.4"><b> 7.1</b></a></li>4962 <li><tt>rfc850-date</tt> <a href="#rfc.iref.g.17"><b> 7.1</b></a></li>4963 <li><tt>second</tt> <a href="#rfc.iref.g.9"><b> 7.1</b></a></li>4964 <li><tt>Server</tt> <a href="#rfc.iref.g.59"><b>1 0.17</b></a></li>4965 <li><tt>subtype</tt> <a href="#rfc.iref.g.26"><b> 7.5</b></a></li>4966 <li><tt>time-of-day</tt> <a href="#rfc.iref.g.6"><b> 7.1</b></a></li>4967 <li><tt>type</tt> <a href="#rfc.iref.g.25"><b> 7.5</b></a></li>4968 <li><tt>User-Agent</tt> <a href="#rfc.iref.g.60"><b>1 0.18</b></a></li>4969 <li><tt>value</tt> <a href="#rfc.iref.g.29"><b> 7.5</b></a></li>4970 <li><tt>weight</tt> <a href="#rfc.iref.g.31"><b> 9.3</b></a></li>4971 <li><tt>year</tt> <a href="#rfc.iref.g.14"><b> 7.1</b></a></li>4951 <li><tt>minute</tt> <a href="#rfc.iref.g.8"><b>8.1</b></a></li> 4952 <li><tt>month</tt> <a href="#rfc.iref.g.13"><b>8.1</b></a></li> 4953 <li><tt>obs-date</tt> <a href="#rfc.iref.g.16"><b>8.1</b></a></li> 4954 <li><tt>parameter</tt> <a href="#rfc.iref.g.27"><b>8.5</b></a></li> 4955 <li><tt>product</tt> <a href="#rfc.iref.g.19"><b>8.2</b></a></li> 4956 <li><tt>product-version</tt> <a href="#rfc.iref.g.20"><b>8.2</b></a></li> 4957 <li><tt>qvalue</tt> <a href="#rfc.iref.g.32"><b>10.3</b></a></li> 4958 <li><tt>Referer</tt> <a href="#rfc.iref.g.56"><b>11.15</b></a></li> 4959 <li><tt>Retry-After</tt> <a href="#rfc.iref.g.57"><b>11.16</b></a></li> 4960 <li><tt>rfc1123-date</tt> <a href="#rfc.iref.g.4"><b>8.1</b></a></li> 4961 <li><tt>rfc850-date</tt> <a href="#rfc.iref.g.17"><b>8.1</b></a></li> 4962 <li><tt>second</tt> <a href="#rfc.iref.g.9"><b>8.1</b></a></li> 4963 <li><tt>Server</tt> <a href="#rfc.iref.g.59"><b>11.17</b></a></li> 4964 <li><tt>subtype</tt> <a href="#rfc.iref.g.26"><b>8.5</b></a></li> 4965 <li><tt>time-of-day</tt> <a href="#rfc.iref.g.6"><b>8.1</b></a></li> 4966 <li><tt>type</tt> <a href="#rfc.iref.g.25"><b>8.5</b></a></li> 4967 <li><tt>User-Agent</tt> <a href="#rfc.iref.g.60"><b>11.18</b></a></li> 4968 <li><tt>value</tt> <a href="#rfc.iref.g.29"><b>8.5</b></a></li> 4969 <li><tt>weight</tt> <a href="#rfc.iref.g.31"><b>10.3</b></a></li> 4970 <li><tt>year</tt> <a href="#rfc.iref.g.14"><b>8.1</b></a></li> 4972 4971 </ul> 4973 4972 </li> 4974 <li>gzip (Coding Format) <a href="#rfc.iref.g.23"> 7.4</a></li>4973 <li>gzip (Coding Format) <a href="#rfc.iref.g.23">8.4</a></li> 4975 4974 </ul> 4976 4975 </li> 4977 4976 <li><a id="rfc.index.H" href="#rfc.index.H"><b>H</b></a><ul> 4978 <li>HEAD method <a href="#rfc.xref.HEAD.1">4.1</a>, <a href="#rfc.iref.h.1"><b>4.3.2</b></a>, <a href="#rfc.xref.HEAD.2">1 1.1.3</a></li>4977 <li>HEAD method <a href="#rfc.xref.HEAD.1">4.1</a>, <a href="#rfc.iref.h.1"><b>4.3.2</b></a>, <a href="#rfc.xref.HEAD.2">12.1.3</a></li> 4979 4978 <li>Header Fields 4980 4979 <ul> 4981 <li>Accept <a href="#rfc.xref.header.accept.1">5 .5</a>, <a href="#rfc.xref.header.accept.2">7.5</a>, <a href="#rfc.xref.header.accept.3">9.1</a>, <a href="#rfc.iref.h.2"><b>10.1</b></a>, <a href="#rfc.xref.header.accept.4">11.3.2</a></li>4982 <li>Accept-Charset <a href="#rfc.xref.header.accept-charset.1">5 .5</a>, <a href="#rfc.xref.header.accept-charset.2">9.1</a>, <a href="#rfc.iref.h.3"><b>10.2</b></a>, <a href="#rfc.xref.header.accept-charset.3">11.3.2</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li>4983 <li>Accept-Encoding <a href="#rfc.xref.header.accept-encoding.1">5 .5</a>, <a href="#rfc.xref.header.accept-encoding.2">7.4</a>, <a href="#rfc.xref.header.accept-encoding.3">9.1</a>, <a href="#rfc.iref.h.4"><b>10.3</b></a>, <a href="#rfc.xref.header.accept-encoding.4">11.3.2</a>, <a href="#rfc.xref.header.accept-encoding.5">11.4.2</a></li>4984 <li>Accept-Language <a href="#rfc.xref.header.accept-language.1">5 .5</a>, <a href="#rfc.xref.header.accept-language.2">9.1</a>, <a href="#rfc.iref.h.5"><b>10.4</b></a>, <a href="#rfc.xref.header.accept-language.3">11.3.2</a></li>4985 <li>Allow <a href="#rfc.xref.header.allow.1">4.1</a>, <a href="#rfc.xref.header.allow.2"> 5.6</a>, <a href="#rfc.iref.h.6"><b>10.5</b></a>, <a href="#rfc.xref.header.allow.3">11.3.2</a>, <a href="#rfc.xref.header.allow.4">C</a></li>4986 <li>Content-Encoding <a href="#rfc.xref.header.content-encoding.1">3.2</a>, <a href="#rfc.xref.header.content-encoding.2"> 7.4</a>, <a href="#rfc.iref.h.7"><b>10.6</b></a>, <a href="#rfc.xref.header.content-encoding.3">11.3.2</a></li>4987 <li>Content-Language <a href="#rfc.xref.header.content-language.1">3.2</a>, <a href="#rfc.iref.h.8"><b>1 0.7</b></a>, <a href="#rfc.xref.header.content-language.2">11.3.2</a></li>4988 <li>Content-Location <a href="#rfc.xref.header.content-location.1">3.2</a>, <a href="#rfc.xref.header.content-location.2">4.3.3</a>, <a href="#rfc.iref.h.9"><b>1 0.8</b></a>, <a href="#rfc.xref.header.content-location.3">10.13</a>, <a href="#rfc.xref.header.content-location.4">11.3.2</a>, <a href="#rfc.xref.header.content-location.5">C</a></li>4980 <li>Accept <a href="#rfc.xref.header.accept.1">5</a>, <a href="#rfc.xref.header.accept.2">8.5</a>, <a href="#rfc.xref.header.accept.3">10.1</a>, <a href="#rfc.iref.h.2"><b>11.1</b></a>, <a href="#rfc.xref.header.accept.4">12.3.2</a></li> 4981 <li>Accept-Charset <a href="#rfc.xref.header.accept-charset.1">5</a>, <a href="#rfc.xref.header.accept-charset.2">10.1</a>, <a href="#rfc.iref.h.3"><b>11.2</b></a>, <a href="#rfc.xref.header.accept-charset.3">12.3.2</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li> 4982 <li>Accept-Encoding <a href="#rfc.xref.header.accept-encoding.1">5</a>, <a href="#rfc.xref.header.accept-encoding.2">8.4</a>, <a href="#rfc.xref.header.accept-encoding.3">10.1</a>, <a href="#rfc.iref.h.4"><b>11.3</b></a>, <a href="#rfc.xref.header.accept-encoding.4">12.3.2</a>, <a href="#rfc.xref.header.accept-encoding.5">12.4.2</a></li> 4983 <li>Accept-Language <a href="#rfc.xref.header.accept-language.1">5</a>, <a href="#rfc.xref.header.accept-language.2">10.1</a>, <a href="#rfc.iref.h.5"><b>11.4</b></a>, <a href="#rfc.xref.header.accept-language.3">12.3.2</a></li> 4984 <li>Allow <a href="#rfc.xref.header.allow.1">4.1</a>, <a href="#rfc.xref.header.allow.2">7</a>, <a href="#rfc.iref.h.6"><b>11.5</b></a>, <a href="#rfc.xref.header.allow.3">12.3.2</a>, <a href="#rfc.xref.header.allow.4">C</a></li> 4985 <li>Content-Encoding <a href="#rfc.xref.header.content-encoding.1">3.2</a>, <a href="#rfc.xref.header.content-encoding.2">8.4</a>, <a href="#rfc.iref.h.7"><b>11.6</b></a>, <a href="#rfc.xref.header.content-encoding.3">12.3.2</a></li> 4986 <li>Content-Language <a href="#rfc.xref.header.content-language.1">3.2</a>, <a href="#rfc.iref.h.8"><b>11.7</b></a>, <a href="#rfc.xref.header.content-language.2">12.3.2</a></li> 4987 <li>Content-Location <a href="#rfc.xref.header.content-location.1">3.2</a>, <a href="#rfc.xref.header.content-location.2">4.3.3</a>, <a href="#rfc.iref.h.9"><b>11.8</b></a>, <a href="#rfc.xref.header.content-location.3">11.13</a>, <a href="#rfc.xref.header.content-location.4">12.3.2</a>, <a href="#rfc.xref.header.content-location.5">C</a></li> 4989 4988 <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> 4990 <li>Content-Type <a href="#rfc.xref.header.content-type.1">3.2</a>, <a href="#rfc.xref.header.content-type.2">6</a>, <a href="#rfc.xref.header.content-type.3"> 7.5</a>, <a href="#rfc.iref.h.10"><b>10.9</b></a>, <a href="#rfc.xref.header.content-type.4">11.3.1</a>, <a href="#rfc.xref.header.content-type.5">11.3.2</a></li>4991 <li>Date <a href="#rfc.xref.header.date.1"> 5.6</a>, <a href="#rfc.iref.h.11"><b>10.10</b></a>, <a href="#rfc.xref.header.date.2">11.3.2</a></li>4992 <li>Expect <a href="#rfc.xref.header.expect.1">5 .5</a>, <a href="#rfc.xref.header.expect.2">6.5.14</a>, <a href="#rfc.iref.h.12"><b>10.11</b></a>, <a href="#rfc.xref.header.expect.3">11.3.2</a>, <a href="#rfc.xref.header.expect.4">C</a></li>4993 <li>From <a href="#rfc.xref.header.from.1">5 .5</a>, <a href="#rfc.iref.h.13"><b>10.12</b></a>, <a href="#rfc.xref.header.from.2">11.3.2</a></li>4994 <li>Location <a href="#rfc.xref.header.location.1">4.3.3</a>, <a href="#rfc.xref.header.location.2"> 5.6</a>, <a href="#rfc.xref.header.location.3">6.4</a>, <a href="#rfc.iref.h.14"><b>10.13</b></a>, <a href="#rfc.xref.header.location.4">11.3.2</a>, <a href="#rfc.xref.header.location.5">C</a></li>4995 <li>Max-Forwards <a href="#rfc.xref.header.max-forwards.1">4.3.7</a>, <a href="#rfc.xref.header.max-forwards.2">4.3.8</a>, <a href="#rfc.xref.header.max-forwards.3">5 .5</a>, <a href="#rfc.iref.h.15"><b>10.14</b></a>, <a href="#rfc.xref.header.max-forwards.4">11.3.2</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li>4996 <li>MIME-Version <a href="#rfc.xref.mime-version.1">1 1.3.2</a>, <a href="#rfc.iref.h.20"><b>A.1</b></a></li>4997 <li>Referer <a href="#rfc.xref.header.referer.1">5 .5</a>, <a href="#rfc.iref.h.16"><b>10.15</b></a>, <a href="#rfc.xref.header.referer.2">11.3.2</a>, <a href="#rfc.xref.header.referer.3">C</a></li>4998 <li>Retry-After <a href="#rfc.xref.header.retry-after.1"> 5.6</a>, <a href="#rfc.xref.header.retry-after.2">6.6.4</a>, <a href="#rfc.iref.h.17"><b>10.16</b></a>, <a href="#rfc.xref.header.retry-after.3">11.3.2</a></li>4999 <li>Server <a href="#rfc.xref.header.server.1"> 5.6</a>, <a href="#rfc.iref.h.18"><b>10.17</b></a>, <a href="#rfc.xref.header.server.2">11.3.2</a>, <a href="#rfc.xref.header.server.3">12.1</a>, <a href="#rfc.xref.header.server.4">C</a></li>5000 <li>User-Agent <a href="#rfc.xref.header.user-agent.1">5 .5</a>, <a href="#rfc.xref.header.user-agent.2">9.1</a>, <a href="#rfc.iref.h.19"><b>10.18</b></a>, <a href="#rfc.xref.header.user-agent.3">11.3.2</a>, <a href="#rfc.xref.header.user-agent.4">12.1</a></li>4989 <li>Content-Type <a href="#rfc.xref.header.content-type.1">3.2</a>, <a href="#rfc.xref.header.content-type.2">6</a>, <a href="#rfc.xref.header.content-type.3">8.5</a>, <a href="#rfc.iref.h.10"><b>11.9</b></a>, <a href="#rfc.xref.header.content-type.4">12.3.1</a>, <a href="#rfc.xref.header.content-type.5">12.3.2</a></li> 4990 <li>Date <a href="#rfc.xref.header.date.1">7</a>, <a href="#rfc.iref.h.11"><b>11.10</b></a>, <a href="#rfc.xref.header.date.2">12.3.2</a></li> 4991 <li>Expect <a href="#rfc.xref.header.expect.1">5</a>, <a href="#rfc.xref.header.expect.2">6.5.14</a>, <a href="#rfc.iref.h.12"><b>11.11</b></a>, <a href="#rfc.xref.header.expect.3">12.3.2</a>, <a href="#rfc.xref.header.expect.4">C</a></li> 4992 <li>From <a href="#rfc.xref.header.from.1">5</a>, <a href="#rfc.iref.h.13"><b>11.12</b></a>, <a href="#rfc.xref.header.from.2">12.3.2</a></li> 4993 <li>Location <a href="#rfc.xref.header.location.1">4.3.3</a>, <a href="#rfc.xref.header.location.2">6.4</a>, <a href="#rfc.xref.header.location.3">7</a>, <a href="#rfc.iref.h.14"><b>11.13</b></a>, <a href="#rfc.xref.header.location.4">12.3.2</a>, <a href="#rfc.xref.header.location.5">C</a></li> 4994 <li>Max-Forwards <a href="#rfc.xref.header.max-forwards.1">4.3.7</a>, <a href="#rfc.xref.header.max-forwards.2">4.3.8</a>, <a href="#rfc.xref.header.max-forwards.3">5</a>, <a href="#rfc.iref.h.15"><b>11.14</b></a>, <a href="#rfc.xref.header.max-forwards.4">12.3.2</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li> 4995 <li>MIME-Version <a href="#rfc.xref.mime-version.1">12.3.2</a>, <a href="#rfc.iref.h.20"><b>A.1</b></a></li> 4996 <li>Referer <a href="#rfc.xref.header.referer.1">5</a>, <a href="#rfc.iref.h.16"><b>11.15</b></a>, <a href="#rfc.xref.header.referer.2">12.3.2</a>, <a href="#rfc.xref.header.referer.3">C</a></li> 4997 <li>Retry-After <a href="#rfc.xref.header.retry-after.1">6.6.4</a>, <a href="#rfc.xref.header.retry-after.2">7</a>, <a href="#rfc.iref.h.17"><b>11.16</b></a>, <a href="#rfc.xref.header.retry-after.3">12.3.2</a></li> 4998 <li>Server <a href="#rfc.xref.header.server.1">7</a>, <a href="#rfc.iref.h.18"><b>11.17</b></a>, <a href="#rfc.xref.header.server.2">12.3.2</a>, <a href="#rfc.xref.header.server.3">13.1</a>, <a href="#rfc.xref.header.server.4">C</a></li> 4999 <li>User-Agent <a href="#rfc.xref.header.user-agent.1">5</a>, <a href="#rfc.xref.header.user-agent.2">10.1</a>, <a href="#rfc.iref.h.19"><b>11.18</b></a>, <a href="#rfc.xref.header.user-agent.3">12.3.2</a>, <a href="#rfc.xref.header.user-agent.4">13.1</a></li> 5001 5000 </ul> 5002 5001 </li> … … 5008 5007 </li> 5009 5008 <li><a id="rfc.index.L" href="#rfc.index.L"><b>L</b></a><ul> 5010 <li>Location header field <a href="#rfc.xref.header.location.1">4.3.3</a>, <a href="#rfc.xref.header.location.2"> 5.6</a>, <a href="#rfc.xref.header.location.3">6.4</a>, <a href="#rfc.iref.l.1"><b>10.13</b></a>, <a href="#rfc.xref.header.location.4">11.3.2</a>, <a href="#rfc.xref.header.location.5">C</a></li>5009 <li>Location header field <a href="#rfc.xref.header.location.1">4.3.3</a>, <a href="#rfc.xref.header.location.2">6.4</a>, <a href="#rfc.xref.header.location.3">7</a>, <a href="#rfc.iref.l.1"><b>11.13</b></a>, <a href="#rfc.xref.header.location.4">12.3.2</a>, <a href="#rfc.xref.header.location.5">C</a></li> 5011 5010 </ul> 5012 5011 </li> 5013 5012 <li><a id="rfc.index.M" href="#rfc.index.M"><b>M</b></a><ul> 5014 <li>Max-Forwards header field <a href="#rfc.xref.header.max-forwards.1">4.3.7</a>, <a href="#rfc.xref.header.max-forwards.2">4.3.8</a>, <a href="#rfc.xref.header.max-forwards.3">5 .5</a>, <a href="#rfc.iref.m.9"><b>10.14</b></a>, <a href="#rfc.xref.header.max-forwards.4">11.3.2</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li>5013 <li>Max-Forwards header field <a href="#rfc.xref.header.max-forwards.1">4.3.7</a>, <a href="#rfc.xref.header.max-forwards.2">4.3.8</a>, <a href="#rfc.xref.header.max-forwards.3">5</a>, <a href="#rfc.iref.m.9"><b>11.14</b></a>, <a href="#rfc.xref.header.max-forwards.4">12.3.2</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li> 5015 5014 <li>Methods 5016 5015 <ul> 5017 <li>CONNECT <a href="#rfc.xref.CONNECT.1">4.1</a>, <a href="#rfc.iref.m.6"><b>4.3.6</b></a>, <a href="#rfc.xref.CONNECT.2">1 1.1.3</a>, <a href="#rfc.xref.CONNECT.3">C</a></li>5018 <li>DELETE <a href="#rfc.xref.DELETE.1">4.1</a>, <a href="#rfc.iref.m.5"><b>4.3.5</b></a>, <a href="#rfc.xref.DELETE.2">1 1.1.3</a></li>5019 <li>GET <a href="#rfc.xref.GET.1">4.1</a>, <a href="#rfc.iref.m.1"><b>4.3.1</b></a>, <a href="#rfc.xref.GET.2">1 1.1.3</a></li>5020 <li>HEAD <a href="#rfc.xref.HEAD.1">4.1</a>, <a href="#rfc.iref.m.2"><b>4.3.2</b></a>, <a href="#rfc.xref.HEAD.2">1 1.1.3</a></li>5021 <li>OPTIONS <a href="#rfc.xref.OPTIONS.1">4.1</a>, <a href="#rfc.iref.m.7"><b>4.3.7</b></a>, <a href="#rfc.xref.OPTIONS.2">1 0.14</a>, <a href="#rfc.xref.OPTIONS.3">11.1.3</a></li>5022 <li>POST <a href="#rfc.xref.POST.1">4.1</a>, <a href="#rfc.iref.m.3"><b>4.3.3</b></a>, <a href="#rfc.xref.POST.2">1 1.1.3</a>, <a href="#rfc.xref.POST.3">C</a></li>5023 <li>PUT <a href="#rfc.xref.PUT.1">4.1</a>, <a href="#rfc.iref.m.4"><b>4.3.4</b></a>, <a href="#rfc.xref.PUT.2">1 1.1.3</a>, <a href="#rfc.xref.PUT.3">C</a></li>5024 <li>TRACE <a href="#rfc.xref.TRACE.1">4.1</a>, <a href="#rfc.iref.m.8"><b>4.3.8</b></a>, <a href="#rfc.xref.TRACE.2">1 0.14</a>, <a href="#rfc.xref.TRACE.3">11.1.3</a>, <a href="#rfc.xref.TRACE.4">12.1</a></li>5016 <li>CONNECT <a href="#rfc.xref.CONNECT.1">4.1</a>, <a href="#rfc.iref.m.6"><b>4.3.6</b></a>, <a href="#rfc.xref.CONNECT.2">12.1.3</a>, <a href="#rfc.xref.CONNECT.3">C</a></li> 5017 <li>DELETE <a href="#rfc.xref.DELETE.1">4.1</a>, <a href="#rfc.iref.m.5"><b>4.3.5</b></a>, <a href="#rfc.xref.DELETE.2">12.1.3</a></li> 5018 <li>GET <a href="#rfc.xref.GET.1">4.1</a>, <a href="#rfc.iref.m.1"><b>4.3.1</b></a>, <a href="#rfc.xref.GET.2">12.1.3</a></li> 5019 <li>HEAD <a href="#rfc.xref.HEAD.1">4.1</a>, <a href="#rfc.iref.m.2"><b>4.3.2</b></a>, <a href="#rfc.xref.HEAD.2">12.1.3</a></li> 5020 <li>OPTIONS <a href="#rfc.xref.OPTIONS.1">4.1</a>, <a href="#rfc.iref.m.7"><b>4.3.7</b></a>, <a href="#rfc.xref.OPTIONS.2">11.14</a>, <a href="#rfc.xref.OPTIONS.3">12.1.3</a></li> 5021 <li>POST <a href="#rfc.xref.POST.1">4.1</a>, <a href="#rfc.iref.m.3"><b>4.3.3</b></a>, <a href="#rfc.xref.POST.2">12.1.3</a>, <a href="#rfc.xref.POST.3">C</a></li> 5022 <li>PUT <a href="#rfc.xref.PUT.1">4.1</a>, <a href="#rfc.iref.m.4"><b>4.3.4</b></a>, <a href="#rfc.xref.PUT.2">12.1.3</a>, <a href="#rfc.xref.PUT.3">C</a></li> 5023 <li>TRACE <a href="#rfc.xref.TRACE.1">4.1</a>, <a href="#rfc.iref.m.8"><b>4.3.8</b></a>, <a href="#rfc.xref.TRACE.2">11.14</a>, <a href="#rfc.xref.TRACE.3">12.1.3</a>, <a href="#rfc.xref.TRACE.4">13.1</a></li> 5025 5024 </ul> 5026 5025 </li> 5027 <li>MIME-Version header field <a href="#rfc.xref.mime-version.1">1 1.3.2</a>, <a href="#rfc.iref.m.10"><b>A.1</b></a></li>5026 <li>MIME-Version header field <a href="#rfc.xref.mime-version.1">12.3.2</a>, <a href="#rfc.iref.m.10"><b>A.1</b></a></li> 5028 5027 </ul> 5029 5028 </li> 5030 5029 <li><a id="rfc.index.O" href="#rfc.index.O"><b>O</b></a><ul> 5031 <li>OPTIONS method <a href="#rfc.xref.OPTIONS.1">4.1</a>, <a href="#rfc.iref.o.1"><b>4.3.7</b></a>, <a href="#rfc.xref.OPTIONS.2">1 0.14</a>, <a href="#rfc.xref.OPTIONS.3">11.1.3</a></li>5030 <li>OPTIONS method <a href="#rfc.xref.OPTIONS.1">4.1</a>, <a href="#rfc.iref.o.1"><b>4.3.7</b></a>, <a href="#rfc.xref.OPTIONS.2">11.14</a>, <a href="#rfc.xref.OPTIONS.3">12.1.3</a></li> 5032 5031 </ul> 5033 5032 </li> 5034 5033 <li><a id="rfc.index.P" href="#rfc.index.P"><b>P</b></a><ul> 5035 <li><em>Part1</em> <a href="#rfc.xref.Part1.1">1</a>, <a href="#rfc.xref.Part1.2">1.1</a>, <a href="#rfc.xref.Part1.3">1.2</a>, <a href="#rfc.xref.Part1.4">2</a>, <a href="#rfc.xref.Part1.5">2</a>, <a href="#rfc.xref.Part1.6">2</a>, <a href="#rfc.xref.Part1.7">3</a>, <a href="#rfc.xref.Part1.8">3.1</a>, <a href="#rfc.xref.Part1.9">4.3.6</a>, <a href="#rfc.xref.Part1.10">4.3.7</a>, <a href="#rfc.xref.Part1.11">4.3.8</a>, <a href="#rfc.xref.Part1.12">4.3.8</a>, <a href="#rfc.xref.Part1.13">5 .5</a>, <a href="#rfc.xref.Part1.14">5.5</a>, <a href="#rfc.xref.Part1.15">5.6</a>, <a href="#rfc.xref.Part1.16">6.2.1</a>, <a href="#rfc.xref.Part1.17">6.2.2</a>, <a href="#rfc.xref.Part1.18">6.3.4</a>, <a href="#rfc.xref.Part1.19">6.3.6</a>, <a href="#rfc.xref.Part1.20">6.5.15</a>, <a href="#rfc.xref.Part1.21">6.6.6</a>, <a href="#rfc.xref.Part1.22">7.4</a>, <a href="#rfc.xref.Part1.23">7.4</a>, <a href="#rfc.xref.Part1.24">7.4</a>, <a href="#rfc.xref.Part1.25">8.1</a>, <a href="#rfc.xref.Part1.26">8.2</a>, <a href="#rfc.xref.Part1.27">10.8</a>, <a href="#rfc.xref.Part1.28">10.11</a>, <a href="#rfc.xref.Part1.29">10.17</a>, <a href="#rfc.xref.Part1.30">10.17</a>, <a href="#rfc.xref.Part1.31">10.18</a>, <a href="#rfc.xref.Part1.32">11.1.2</a>, <a href="#rfc.xref.Part1.33">11.3.1</a>, <a href="#rfc.xref.Part1.34">11.3.1</a>, <a href="#rfc.xref.Part1.35">11.3.1</a>, <a href="#rfc.xref.Part1.36">11.3.1</a>, <a href="#rfc.xref.Part1.37">11.3.1</a>, <a href="#rfc.xref.Part1.38">11.3.1</a>, <a href="#rfc.xref.Part1.39">11.4</a>, <a href="#rfc.xref.Part1.40">11.4.1</a>, <a href="#rfc.xref.Part1.41">11.4.1</a>, <a href="#rfc.xref.Part1.42">11.4.2</a>, <a href="#rfc.xref.Part1.43">11.4.2</a>, <a href="#rfc.xref.Part1.44">11.4.2</a>, <a href="#rfc.xref.Part1.45">13</a>, <a href="#Part1"><b>14.1</b></a>, <a href="#rfc.xref.Part1.46">C</a>, <a href="#rfc.xref.Part1.47">D</a>, <a href="#rfc.xref.Part1.48">D</a>, <a href="#rfc.xref.Part1.49">D</a>, <a href="#rfc.xref.Part1.50">D</a>, <a href="#rfc.xref.Part1.51">D</a>, <a href="#rfc.xref.Part1.52">D</a>, <a href="#rfc.xref.Part1.53">D</a>, <a href="#rfc.xref.Part1.54">D</a>, <a href="#rfc.xref.Part1.55">D</a>, <a href="#rfc.xref.Part1.56">D</a>, <a href="#rfc.xref.Part1.57">D</a><ul>5034 <li><em>Part1</em> <a href="#rfc.xref.Part1.1">1</a>, <a href="#rfc.xref.Part1.2">1.1</a>, <a href="#rfc.xref.Part1.3">1.2</a>, <a href="#rfc.xref.Part1.4">2</a>, <a href="#rfc.xref.Part1.5">2</a>, <a href="#rfc.xref.Part1.6">2</a>, <a href="#rfc.xref.Part1.7">3</a>, <a href="#rfc.xref.Part1.8">3.1</a>, <a href="#rfc.xref.Part1.9">4.3.6</a>, <a href="#rfc.xref.Part1.10">4.3.7</a>, <a href="#rfc.xref.Part1.11">4.3.8</a>, <a href="#rfc.xref.Part1.12">4.3.8</a>, <a href="#rfc.xref.Part1.13">5</a>, <a href="#rfc.xref.Part1.14">5</a>, <a href="#rfc.xref.Part1.15">6.2.1</a>, <a href="#rfc.xref.Part1.16">6.2.2</a>, <a href="#rfc.xref.Part1.17">6.3.4</a>, <a href="#rfc.xref.Part1.18">6.3.6</a>, <a href="#rfc.xref.Part1.19">6.5.15</a>, <a href="#rfc.xref.Part1.20">6.6.6</a>, <a href="#rfc.xref.Part1.21">7</a>, <a href="#rfc.xref.Part1.22">8.4</a>, <a href="#rfc.xref.Part1.23">8.4</a>, <a href="#rfc.xref.Part1.24">8.4</a>, <a href="#rfc.xref.Part1.25">9.1</a>, <a href="#rfc.xref.Part1.26">9.2</a>, <a href="#rfc.xref.Part1.27">11.8</a>, <a href="#rfc.xref.Part1.28">11.11</a>, <a href="#rfc.xref.Part1.29">11.17</a>, <a href="#rfc.xref.Part1.30">11.17</a>, <a href="#rfc.xref.Part1.31">11.18</a>, <a href="#rfc.xref.Part1.32">12.1.2</a>, <a href="#rfc.xref.Part1.33">12.3.1</a>, <a href="#rfc.xref.Part1.34">12.3.1</a>, <a href="#rfc.xref.Part1.35">12.3.1</a>, <a href="#rfc.xref.Part1.36">12.3.1</a>, <a href="#rfc.xref.Part1.37">12.3.1</a>, <a href="#rfc.xref.Part1.38">12.3.1</a>, <a href="#rfc.xref.Part1.39">12.4</a>, <a href="#rfc.xref.Part1.40">12.4.1</a>, <a href="#rfc.xref.Part1.41">12.4.1</a>, <a href="#rfc.xref.Part1.42">12.4.2</a>, <a href="#rfc.xref.Part1.43">12.4.2</a>, <a href="#rfc.xref.Part1.44">12.4.2</a>, <a href="#rfc.xref.Part1.45">14</a>, <a href="#Part1"><b>15.1</b></a>, <a href="#rfc.xref.Part1.46">C</a>, <a href="#rfc.xref.Part1.47">D</a>, <a href="#rfc.xref.Part1.48">D</a>, <a href="#rfc.xref.Part1.49">D</a>, <a href="#rfc.xref.Part1.50">D</a>, <a href="#rfc.xref.Part1.51">D</a>, <a href="#rfc.xref.Part1.52">D</a>, <a href="#rfc.xref.Part1.53">D</a>, <a href="#rfc.xref.Part1.54">D</a>, <a href="#rfc.xref.Part1.55">D</a>, <a href="#rfc.xref.Part1.56">D</a>, <a href="#rfc.xref.Part1.57">D</a><ul> 5036 5035 <li><em>Section 1.2</em> <a href="#rfc.xref.Part1.3">1.2</a></li> 5037 <li><em>Section 2.3</em> <a href="#rfc.xref.Part1.1 8">6.3.4</a></li>5036 <li><em>Section 2.3</em> <a href="#rfc.xref.Part1.17">6.3.4</a></li> 5038 5037 <li><em>Section 2.5</em> <a href="#rfc.xref.Part1.2">1.1</a></li> 5039 <li><em>Section 2.6</em> <a href="#rfc.xref.Part1.2 1">6.6.6</a></li>5038 <li><em>Section 2.6</em> <a href="#rfc.xref.Part1.20">6.6.6</a></li> 5040 5039 <li><em>Section 2.7</em> <a href="#rfc.xref.Part1.4">2</a>, <a href="#rfc.xref.Part1.54">D</a>, <a href="#rfc.xref.Part1.56">D</a>, <a href="#rfc.xref.Part1.57">D</a></li> 5041 <li><em>Section 3.2</em> <a href="#rfc.xref.Part1.29">1 0.17</a>, <a href="#rfc.xref.Part1.31">10.18</a>, <a href="#rfc.xref.Part1.33">11.3.1</a>, <a href="#rfc.xref.Part1.36">11.3.1</a></li>5040 <li><em>Section 3.2</em> <a href="#rfc.xref.Part1.29">11.17</a>, <a href="#rfc.xref.Part1.31">11.18</a>, <a href="#rfc.xref.Part1.33">12.3.1</a>, <a href="#rfc.xref.Part1.36">12.3.1</a></li> 5042 5041 <li><em>Section 3.2.1</em> <a href="#rfc.xref.Part1.48">D</a>, <a href="#rfc.xref.Part1.49">D</a>, <a href="#rfc.xref.Part1.50">D</a></li> 5043 <li><em>Section 3.2.4</em> <a href="#rfc.xref.Part1.35">1 1.3.1</a>, <a href="#rfc.xref.Part1.51">D</a>, <a href="#rfc.xref.Part1.52">D</a>, <a href="#rfc.xref.Part1.53">D</a>, <a href="#rfc.xref.Part1.55">D</a></li>5044 <li><em>Section 3.3</em> <a href="#rfc.xref.Part1.7">3</a>, <a href="#rfc.xref.Part1.1 9">6.3.6</a>, <a href="#rfc.xref.Part1.26">8.2</a>, <a href="#rfc.xref.Part1.32">11.1.2</a></li>5045 <li><em>Section 3.3.2</em> <a href="#rfc.xref.Part1.25"> 8.1</a></li>5046 <li><em>Section 4</em> <a href="#rfc.xref.Part1.40">1 1.4.1</a></li>5047 <li><em>Section 4.1</em> <a href="#rfc.xref.Part1.38">1 1.3.1</a></li>5048 <li><em>Section 4.2.1</em> <a href="#rfc.xref.Part1.22"> 7.4</a>, <a href="#rfc.xref.Part1.42">11.4.2</a></li>5049 <li><em>Section 4.2</em> <a href="#rfc.xref.Part1.39">1 1.4</a>, <a href="#rfc.xref.Part1.41">11.4.1</a></li>5050 <li><em>Section 4.2.2</em> <a href="#rfc.xref.Part1.23"> 7.4</a>, <a href="#rfc.xref.Part1.43">11.4.2</a></li>5051 <li><em>Section 4.2.3</em> <a href="#rfc.xref.Part1.24"> 7.4</a>, <a href="#rfc.xref.Part1.44">11.4.2</a></li>5052 <li><em>Section 4.3</em> <a href="#rfc.xref.Part1.14">5 .5</a></li>5042 <li><em>Section 3.2.4</em> <a href="#rfc.xref.Part1.35">12.3.1</a>, <a href="#rfc.xref.Part1.51">D</a>, <a href="#rfc.xref.Part1.52">D</a>, <a href="#rfc.xref.Part1.53">D</a>, <a href="#rfc.xref.Part1.55">D</a></li> 5043 <li><em>Section 3.3</em> <a href="#rfc.xref.Part1.7">3</a>, <a href="#rfc.xref.Part1.18">6.3.6</a>, <a href="#rfc.xref.Part1.26">9.2</a>, <a href="#rfc.xref.Part1.32">12.1.2</a></li> 5044 <li><em>Section 3.3.2</em> <a href="#rfc.xref.Part1.25">9.1</a></li> 5045 <li><em>Section 4</em> <a href="#rfc.xref.Part1.40">12.4.1</a></li> 5046 <li><em>Section 4.1</em> <a href="#rfc.xref.Part1.38">12.3.1</a></li> 5047 <li><em>Section 4.2.1</em> <a href="#rfc.xref.Part1.22">8.4</a>, <a href="#rfc.xref.Part1.42">12.4.2</a></li> 5048 <li><em>Section 4.2</em> <a href="#rfc.xref.Part1.39">12.4</a>, <a href="#rfc.xref.Part1.41">12.4.1</a></li> 5049 <li><em>Section 4.2.2</em> <a href="#rfc.xref.Part1.23">8.4</a>, <a href="#rfc.xref.Part1.43">12.4.2</a></li> 5050 <li><em>Section 4.2.3</em> <a href="#rfc.xref.Part1.24">8.4</a>, <a href="#rfc.xref.Part1.44">12.4.2</a></li> 5051 <li><em>Section 4.3</em> <a href="#rfc.xref.Part1.14">5</a></li> 5053 5052 <li><em>Section 5.3</em> <a href="#rfc.xref.Part1.5">2</a>, <a href="#rfc.xref.Part1.9">4.3.6</a>, <a href="#rfc.xref.Part1.10">4.3.7</a></li> 5054 <li><em>Section 5.4</em> <a href="#rfc.xref.Part1.13">5 .5</a></li>5055 <li><em>Section 5.5</em> <a href="#rfc.xref.Part1.6">2</a>, <a href="#rfc.xref.Part1.8">3.1</a>, <a href="#rfc.xref.Part1. 15">5.6</a>, <a href="#rfc.xref.Part1.27">10.8</a></li>5056 <li><em>Section 5.7</em> <a href="#rfc.xref.Part1.11">4.3.8</a>, <a href="#rfc.xref.Part1.30">1 0.17</a>, <a href="#rfc.xref.Part1.46">C</a></li>5057 <li><em>Section 6.1</em> <a href="#rfc.xref.Part1.37">1 1.3.1</a></li>5058 <li><em>Section 6.3</em> <a href="#rfc.xref.Part1.1 6">6.2.1</a>, <a href="#rfc.xref.Part1.28">10.11</a></li>5059 <li><em>Section 6.4</em> <a href="#rfc.xref.Part1.1 7">6.2.2</a>, <a href="#rfc.xref.Part1.20">6.5.15</a></li>5053 <li><em>Section 5.4</em> <a href="#rfc.xref.Part1.13">5</a></li> 5054 <li><em>Section 5.5</em> <a href="#rfc.xref.Part1.6">2</a>, <a href="#rfc.xref.Part1.8">3.1</a>, <a href="#rfc.xref.Part1.21">7</a>, <a href="#rfc.xref.Part1.27">11.8</a></li> 5055 <li><em>Section 5.7</em> <a href="#rfc.xref.Part1.11">4.3.8</a>, <a href="#rfc.xref.Part1.30">11.17</a>, <a href="#rfc.xref.Part1.46">C</a></li> 5056 <li><em>Section 6.1</em> <a href="#rfc.xref.Part1.37">12.3.1</a></li> 5057 <li><em>Section 6.3</em> <a href="#rfc.xref.Part1.15">6.2.1</a>, <a href="#rfc.xref.Part1.28">11.11</a></li> 5058 <li><em>Section 6.4</em> <a href="#rfc.xref.Part1.16">6.2.2</a>, <a href="#rfc.xref.Part1.19">6.5.15</a></li> 5060 5059 <li><em>Section 7.3.1</em> <a href="#rfc.xref.Part1.12">4.3.8</a></li> 5061 <li><em>Section 9</em> <a href="#rfc.xref.Part1.45">1 3</a></li>5062 <li><em>Appendix B</em> <a href="#rfc.xref.Part1.34">1 1.3.1</a></li>5060 <li><em>Section 9</em> <a href="#rfc.xref.Part1.45">14</a></li> 5061 <li><em>Appendix B</em> <a href="#rfc.xref.Part1.34">12.3.1</a></li> 5063 5062 </ul> 5064 5063 </li> 5065 <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">4.3.1</a>, <a href="#rfc.xref.Part4.4">5 .5</a>, <a href="#rfc.xref.Part4.5">5.5</a>, <a href="#rfc.xref.Part4.6">5.5</a>, <a href="#rfc.xref.Part4.7">5.5</a>, <a href="#rfc.xref.Part4.8">5.6</a>, <a href="#rfc.xref.Part4.9">6.1</a>, <a href="#rfc.xref.Part4.10">6.1</a>, <a href="#rfc.xref.Part4.11">6.1</a>, <a href="#rfc.xref.Part4.12">6.3.2</a>, <a href="#rfc.xref.Part4.13">6.4</a>, <a href="#Part4"><b>14.1</b></a>, <a href="#rfc.xref.Part4.14">F.2</a><ul>5064 <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">4.3.1</a>, <a href="#rfc.xref.Part4.4">5</a>, <a href="#rfc.xref.Part4.5">5</a>, <a href="#rfc.xref.Part4.6">5</a>, <a href="#rfc.xref.Part4.7">5</a>, <a href="#rfc.xref.Part4.8">6.1</a>, <a href="#rfc.xref.Part4.9">6.1</a>, <a href="#rfc.xref.Part4.10">6.1</a>, <a href="#rfc.xref.Part4.11">6.3.2</a>, <a href="#rfc.xref.Part4.12">6.4</a>, <a href="#rfc.xref.Part4.13">7</a>, <a href="#Part4"><b>15.1</b></a>, <a href="#rfc.xref.Part4.14">F.2</a><ul> 5066 5065 <li><em>Section 2.2</em> <a href="#rfc.xref.Part4.2">3.2</a></li> 5067 <li><em>Section 2.3</em> <a href="#rfc.xref.Part4.1">3.2</a>, <a href="#rfc.xref.Part4. 8">5.6</a>, <a href="#rfc.xref.Part4.12">6.3.2</a></li>5068 <li><em>Section 3.1</em> <a href="#rfc.xref.Part4.4">5 .5</a></li>5069 <li><em>Section 3.2</em> <a href="#rfc.xref.Part4.6">5 .5</a></li>5070 <li><em>Section 3.3</em> <a href="#rfc.xref.Part4.5">5 .5</a></li>5071 <li><em>Section 3.4</em> <a href="#rfc.xref.Part4.7">5 .5</a></li>5072 <li><em>Section 4</em> <a href="#rfc.xref.Part4. 9">6.1</a></li>5073 <li><em>Section 4.1</em> <a href="#rfc.xref.Part4. 10">6.1</a>, <a href="#rfc.xref.Part4.13">6.4</a></li>5074 <li><em>Section 4.2</em> <a href="#rfc.xref.Part4.1 1">6.1</a></li>5066 <li><em>Section 2.3</em> <a href="#rfc.xref.Part4.1">3.2</a>, <a href="#rfc.xref.Part4.11">6.3.2</a>, <a href="#rfc.xref.Part4.13">7</a></li> 5067 <li><em>Section 3.1</em> <a href="#rfc.xref.Part4.4">5</a></li> 5068 <li><em>Section 3.2</em> <a href="#rfc.xref.Part4.6">5</a></li> 5069 <li><em>Section 3.3</em> <a href="#rfc.xref.Part4.5">5</a></li> 5070 <li><em>Section 3.4</em> <a href="#rfc.xref.Part4.7">5</a></li> 5071 <li><em>Section 4</em> <a href="#rfc.xref.Part4.8">6.1</a></li> 5072 <li><em>Section 4.1</em> <a href="#rfc.xref.Part4.9">6.1</a>, <a href="#rfc.xref.Part4.12">6.4</a></li> 5073 <li><em>Section 4.2</em> <a href="#rfc.xref.Part4.10">6.1</a></li> 5075 5074 </ul> 5076 5075 </li> 5077 <li><em>Part5</em> <a href="#rfc.xref.Part5.1">4.3.1</a>, <a href="#rfc.xref.Part5.2">4.3.1</a>, <a href="#rfc.xref.Part5.3">4.3.4</a>, <a href="#rfc.xref.Part5.4">5 .5</a>, <a href="#rfc.xref.Part5.5">5.5</a>, <a href="#rfc.xref.Part5.6">5.6</a>, <a href="#rfc.xref.Part5.7">6.1</a>, <a href="#rfc.xref.Part5.8">6.1</a>, <a href="#rfc.xref.Part5.9">6.1</a>, <a href="#rfc.xref.Part5.10">8.1</a>, <a href="#Part5"><b>14.1</b></a><ul>5078 <li><em>Section 3</em> <a href="#rfc.xref.Part5. 7">6.1</a></li>5079 <li><em>Section 3.1</em> <a href="#rfc.xref.Part5. 8">6.1</a></li>5080 <li><em>Section 3.2</em> <a href="#rfc.xref.Part5. 9">6.1</a></li>5081 <li><em>Section 5.1</em> <a href="#rfc.xref.Part5. 6">5.6</a></li>5082 <li><em>Section 5.2</em> <a href="#rfc.xref.Part5.3">4.3.4</a>, <a href="#rfc.xref.Part5.10"> 8.1</a></li>5083 <li><em>Section 5.3</em> <a href="#rfc.xref.Part5.4">5 .5</a></li>5084 <li><em>Section 5.4</em> <a href="#rfc.xref.Part5.2">4.3.1</a>, <a href="#rfc.xref.Part5.5">5 .5</a></li>5076 <li><em>Part5</em> <a href="#rfc.xref.Part5.1">4.3.1</a>, <a href="#rfc.xref.Part5.2">4.3.1</a>, <a href="#rfc.xref.Part5.3">4.3.4</a>, <a href="#rfc.xref.Part5.4">5</a>, <a href="#rfc.xref.Part5.5">5</a>, <a href="#rfc.xref.Part5.6">6.1</a>, <a href="#rfc.xref.Part5.7">6.1</a>, <a href="#rfc.xref.Part5.8">6.1</a>, <a href="#rfc.xref.Part5.9">7</a>, <a href="#rfc.xref.Part5.10">9.1</a>, <a href="#Part5"><b>15.1</b></a><ul> 5077 <li><em>Section 3</em> <a href="#rfc.xref.Part5.6">6.1</a></li> 5078 <li><em>Section 3.1</em> <a href="#rfc.xref.Part5.7">6.1</a></li> 5079 <li><em>Section 3.2</em> <a href="#rfc.xref.Part5.8">6.1</a></li> 5080 <li><em>Section 5.1</em> <a href="#rfc.xref.Part5.9">7</a></li> 5081 <li><em>Section 5.2</em> <a href="#rfc.xref.Part5.3">4.3.4</a>, <a href="#rfc.xref.Part5.10">9.1</a></li> 5082 <li><em>Section 5.3</em> <a href="#rfc.xref.Part5.4">5</a></li> 5083 <li><em>Section 5.4</em> <a href="#rfc.xref.Part5.2">4.3.1</a>, <a href="#rfc.xref.Part5.5">5</a></li> 5085 5084 </ul> 5086 5085 </li> 5087 <li><em>Part6</em> <a href="#rfc.xref.Part6.1">3.2</a>, <a href="#rfc.xref.Part6.2">4.2.3</a>, <a href="#rfc.xref.Part6.3">4.3.1</a>, <a href="#rfc.xref.Part6.4">4.3.2</a>, <a href="#rfc.xref.Part6.5">4.3.3</a>, <a href="#rfc.xref.Part6.6">4.3.4</a>, <a href="#rfc.xref.Part6.7">4.3.5</a>, <a href="#rfc.xref.Part6.8"> 5.6</a>, <a href="#rfc.xref.Part6.9">5.6</a>, <a href="#rfc.xref.Part6.10">6.3.1</a>, <a href="#rfc.xref.Part6.11">6.3.4</a>, <a href="#rfc.xref.Part6.12">6.3.4</a>, <a href="#rfc.xref.Part6.13">6.3.4</a>, <a href="#rfc.xref.Part6.14">6.4.1</a>, <a href="#rfc.xref.Part6.15">6.4.2</a>, <a href="#rfc.xref.Part6.16">6.5.9</a>, <a href="#rfc.xref.Part6.17">9.1</a>, <a href="#rfc.xref.Part6.18">11.2.2</a>, <a href="#rfc.xref.Part6.19">11.3.1</a>, <a href="#Part6"><b>14.1</b></a><ul>5086 <li><em>Part6</em> <a href="#rfc.xref.Part6.1">3.2</a>, <a href="#rfc.xref.Part6.2">4.2.3</a>, <a href="#rfc.xref.Part6.3">4.3.1</a>, <a href="#rfc.xref.Part6.4">4.3.2</a>, <a href="#rfc.xref.Part6.5">4.3.3</a>, <a href="#rfc.xref.Part6.6">4.3.4</a>, <a href="#rfc.xref.Part6.7">4.3.5</a>, <a href="#rfc.xref.Part6.8">6.3.1</a>, <a href="#rfc.xref.Part6.9">6.3.4</a>, <a href="#rfc.xref.Part6.10">6.3.4</a>, <a href="#rfc.xref.Part6.11">6.3.4</a>, <a href="#rfc.xref.Part6.12">6.4.1</a>, <a href="#rfc.xref.Part6.13">6.4.2</a>, <a href="#rfc.xref.Part6.14">6.5.9</a>, <a href="#rfc.xref.Part6.15">7</a>, <a href="#rfc.xref.Part6.16">7</a>, <a href="#rfc.xref.Part6.17">10.1</a>, <a href="#rfc.xref.Part6.18">12.2.2</a>, <a href="#rfc.xref.Part6.19">12.3.1</a>, <a href="#Part6"><b>15.1</b></a><ul> 5088 5087 <li><em>Section 4.1.1</em> <a href="#rfc.xref.Part6.5">4.3.3</a></li> 5089 <li><em>Section 4.1.2</em> <a href="#rfc.xref.Part6. 10">6.3.1</a>, <a href="#rfc.xref.Part6.13">6.3.4</a>, <a href="#rfc.xref.Part6.14">6.4.1</a>, <a href="#rfc.xref.Part6.15">6.4.2</a>, <a href="#rfc.xref.Part6.16">6.5.9</a></li>5088 <li><em>Section 4.1.2</em> <a href="#rfc.xref.Part6.8">6.3.1</a>, <a href="#rfc.xref.Part6.11">6.3.4</a>, <a href="#rfc.xref.Part6.12">6.4.1</a>, <a href="#rfc.xref.Part6.13">6.4.2</a>, <a href="#rfc.xref.Part6.14">6.5.9</a></li> 5090 5089 <li><em>Section 5</em> <a href="#rfc.xref.Part6.4">4.3.2</a></li> 5091 5090 <li><em>Section 6</em> <a href="#rfc.xref.Part6.6">4.3.4</a>, <a href="#rfc.xref.Part6.7">4.3.5</a></li> 5092 <li><em>Section 7.1</em> <a href="#rfc.xref.Part6. 8">5.6</a></li>5093 <li><em>Section 7.2</em> <a href="#rfc.xref.Part6. 11">6.3.4</a></li>5091 <li><em>Section 7.1</em> <a href="#rfc.xref.Part6.15">7</a></li> 5092 <li><em>Section 7.2</em> <a href="#rfc.xref.Part6.9">6.3.4</a></li> 5094 5093 <li><em>Section 7.3</em> <a href="#rfc.xref.Part6.1">3.2</a></li> 5095 <li><em>Section 7.5</em> <a href="#rfc.xref.Part6. 9">5.6</a>, <a href="#rfc.xref.Part6.17">9.1</a></li>5096 <li><em>Section 7.6</em> <a href="#rfc.xref.Part6.1 2">6.3.4</a></li>5094 <li><em>Section 7.5</em> <a href="#rfc.xref.Part6.16">7</a>, <a href="#rfc.xref.Part6.17">10.1</a></li> 5095 <li><em>Section 7.6</em> <a href="#rfc.xref.Part6.10">6.3.4</a></li> 5097 5096 </ul> 5098 5097 </li> 5099 <li><em>Part7</em> <a href="#rfc.xref.Part7.1">5 .5</a>, <a href="#rfc.xref.Part7.2">5.5</a>, <a href="#rfc.xref.Part7.3">5.6</a>, <a href="#rfc.xref.Part7.4">5.6</a>, <a href="#rfc.xref.Part7.5">6.1</a>, <a href="#rfc.xref.Part7.6">6.1</a>, <a href="#rfc.xref.Part7.7">6.1</a>, <a href="#Part7"><b>14.1</b></a><ul>5100 <li><em>Section 3</em> <a href="#rfc.xref.Part7. 5">6.1</a></li>5101 <li><em>Section 3.1</em> <a href="#rfc.xref.Part7. 6">6.1</a></li>5102 <li><em>Section 3.2</em> <a href="#rfc.xref.Part7. 7">6.1</a></li>5103 <li><em>Section 4.1</em> <a href="#rfc.xref.Part7.1">5 .5</a></li>5104 <li><em>Section 4.2</em> <a href="#rfc.xref.Part7. 3">5.6</a></li>5105 <li><em>Section 4.3</em> <a href="#rfc.xref.Part7.2">5 .5</a></li>5106 <li><em>Section 4.4</em> <a href="#rfc.xref.Part7. 4">5.6</a></li>5098 <li><em>Part7</em> <a href="#rfc.xref.Part7.1">5</a>, <a href="#rfc.xref.Part7.2">5</a>, <a href="#rfc.xref.Part7.3">6.1</a>, <a href="#rfc.xref.Part7.4">6.1</a>, <a href="#rfc.xref.Part7.5">6.1</a>, <a href="#rfc.xref.Part7.6">7</a>, <a href="#rfc.xref.Part7.7">7</a>, <a href="#Part7"><b>15.1</b></a><ul> 5099 <li><em>Section 3</em> <a href="#rfc.xref.Part7.3">6.1</a></li> 5100 <li><em>Section 3.1</em> <a href="#rfc.xref.Part7.4">6.1</a></li> 5101 <li><em>Section 3.2</em> <a href="#rfc.xref.Part7.5">6.1</a></li> 5102 <li><em>Section 4.1</em> <a href="#rfc.xref.Part7.1">5</a></li> 5103 <li><em>Section 4.2</em> <a href="#rfc.xref.Part7.6">7</a></li> 5104 <li><em>Section 4.3</em> <a href="#rfc.xref.Part7.2">5</a></li> 5105 <li><em>Section 4.4</em> <a href="#rfc.xref.Part7.7">7</a></li> 5107 5106 </ul> 5108 5107 </li> 5109 <li>payload <a href="#rfc.iref.p.3"> 8</a></li>5110 <li>POST method <a href="#rfc.xref.POST.1">4.1</a>, <a href="#rfc.iref.p.1"><b>4.3.3</b></a>, <a href="#rfc.xref.POST.2">1 1.1.3</a>, <a href="#rfc.xref.POST.3">C</a></li>5111 <li>PUT method <a href="#rfc.xref.PUT.1">4.1</a>, <a href="#rfc.iref.p.2"><b>4.3.4</b></a>, <a href="#rfc.xref.PUT.2">1 1.1.3</a>, <a href="#rfc.xref.PUT.3">C</a></li>5108 <li>payload <a href="#rfc.iref.p.3">9</a></li> 5109 <li>POST method <a href="#rfc.xref.POST.1">4.1</a>, <a href="#rfc.iref.p.1"><b>4.3.3</b></a>, <a href="#rfc.xref.POST.2">12.1.3</a>, <a href="#rfc.xref.POST.3">C</a></li> 5110 <li>PUT method <a href="#rfc.xref.PUT.1">4.1</a>, <a href="#rfc.iref.p.2"><b>4.3.4</b></a>, <a href="#rfc.xref.PUT.2">12.1.3</a>, <a href="#rfc.xref.PUT.3">C</a></li> 5112 5111 </ul> 5113 5112 </li> 5114 5113 <li><a id="rfc.index.R" href="#rfc.index.R"><b>R</b></a><ul> 5115 <li>Referer header field <a href="#rfc.xref.header.referer.1">5 .5</a>, <a href="#rfc.iref.r.2"><b>10.15</b></a>, <a href="#rfc.xref.header.referer.2">11.3.2</a>, <a href="#rfc.xref.header.referer.3">C</a></li>5114 <li>Referer header field <a href="#rfc.xref.header.referer.1">5</a>, <a href="#rfc.iref.r.2"><b>11.15</b></a>, <a href="#rfc.xref.header.referer.2">12.3.2</a>, <a href="#rfc.xref.header.referer.3">C</a></li> 5116 5115 <li>representation <a href="#rfc.iref.r.1">3</a></li> 5117 <li><em>REST</em> <a href="#rfc.xref.REST.1">4.1</a>, <a href="#REST"><b>1 4.2</b></a></li>5118 <li>Retry-After header field <a href="#rfc.xref.header.retry-after.1"> 5.6</a>, <a href="#rfc.xref.header.retry-after.2">6.6.4</a>, <a href="#rfc.iref.r.3"><b>10.16</b></a>, <a href="#rfc.xref.header.retry-after.3">11.3.2</a></li>5119 <li><em>RFC1123</em> <a href="#rfc.xref.RFC1123.1"> 7.1</a>, <a href="#rfc.xref.RFC1123.2">7.1</a>, <a href="#RFC1123"><b>14.2</b></a><ul>5120 <li><em>Section 5.2.14</em> <a href="#rfc.xref.RFC1123.2"> 7.1</a></li>5116 <li><em>REST</em> <a href="#rfc.xref.REST.1">4.1</a>, <a href="#REST"><b>15.2</b></a></li> 5117 <li>Retry-After header field <a href="#rfc.xref.header.retry-after.1">6.6.4</a>, <a href="#rfc.xref.header.retry-after.2">7</a>, <a href="#rfc.iref.r.3"><b>11.16</b></a>, <a href="#rfc.xref.header.retry-after.3">12.3.2</a></li> 5118 <li><em>RFC1123</em> <a href="#rfc.xref.RFC1123.1">8.1</a>, <a href="#rfc.xref.RFC1123.2">8.1</a>, <a href="#RFC1123"><b>15.2</b></a><ul> 5119 <li><em>Section 5.2.14</em> <a href="#rfc.xref.RFC1123.2">8.1</a></li> 5121 5120 </ul> 5122 5121 </li> 5123 <li><em>RFC1945</em> <a href="#rfc.xref.RFC1945.1">6.4</a>, <a href="#RFC1945"><b>1 4.2</b></a>, <a href="#rfc.xref.RFC1945.2">B</a><ul>5122 <li><em>RFC1945</em> <a href="#rfc.xref.RFC1945.1">6.4</a>, <a href="#RFC1945"><b>15.2</b></a>, <a href="#rfc.xref.RFC1945.2">B</a><ul> 5124 5123 <li><em>Section 9.3</em> <a href="#rfc.xref.RFC1945.1">6.4</a></li> 5125 5124 </ul> 5126 5125 </li> 5127 <li><em>RFC1950</em> <a href="#rfc.xref.RFC1950.1">1 1.4.2</a>, <a href="#RFC1950"><b>14.1</b></a></li>5128 <li><em>RFC1951</em> <a href="#rfc.xref.RFC1951.1">1 1.4.2</a>, <a href="#RFC1951"><b>14.1</b></a></li>5129 <li><em>RFC1952</em> <a href="#rfc.xref.RFC1952.1">1 1.4.2</a>, <a href="#RFC1952"><b>14.1</b></a></li>5130 <li><em>RFC2045</em> <a href="#RFC2045"><b>1 4.1</b></a>, <a href="#rfc.xref.RFC2045.1">A</a>, <a href="#rfc.xref.RFC2045.2">A.1</a></li>5131 <li><em>RFC2046</em> <a href="#rfc.xref.RFC2046.1">3.3</a>, <a href="#rfc.xref.RFC2046.2"> 7.5</a>, <a href="#rfc.xref.RFC2046.3">7.5.2</a>, <a href="#RFC2046"><b>14.1</b></a>, <a href="#rfc.xref.RFC2046.4">A.2</a><ul>5126 <li><em>RFC1950</em> <a href="#rfc.xref.RFC1950.1">12.4.2</a>, <a href="#RFC1950"><b>15.1</b></a></li> 5127 <li><em>RFC1951</em> <a href="#rfc.xref.RFC1951.1">12.4.2</a>, <a href="#RFC1951"><b>15.1</b></a></li> 5128 <li><em>RFC1952</em> <a href="#rfc.xref.RFC1952.1">12.4.2</a>, <a href="#RFC1952"><b>15.1</b></a></li> 5129 <li><em>RFC2045</em> <a href="#RFC2045"><b>15.1</b></a>, <a href="#rfc.xref.RFC2045.1">A</a>, <a href="#rfc.xref.RFC2045.2">A.1</a></li> 5130 <li><em>RFC2046</em> <a href="#rfc.xref.RFC2046.1">3.3</a>, <a href="#rfc.xref.RFC2046.2">8.5</a>, <a href="#rfc.xref.RFC2046.3">8.5.2</a>, <a href="#RFC2046"><b>15.1</b></a>, <a href="#rfc.xref.RFC2046.4">A.2</a><ul> 5132 5131 <li><em>Section 4.5.1</em> <a href="#rfc.xref.RFC2046.1">3.3</a></li> 5133 <li><em>Section 5.1.1</em> <a href="#rfc.xref.RFC2046.3"> 7.5.2</a></li>5132 <li><em>Section 5.1.1</em> <a href="#rfc.xref.RFC2046.3">8.5.2</a></li> 5134 5133 </ul> 5135 5134 </li> 5136 <li><em>RFC2049</em> <a href="#RFC2049"><b>1 4.2</b></a>, <a href="#rfc.xref.RFC2049.1">A.2</a><ul>5135 <li><em>RFC2049</em> <a href="#RFC2049"><b>15.2</b></a>, <a href="#rfc.xref.RFC2049.1">A.2</a><ul> 5137 5136 <li><em>Section 4</em> <a href="#rfc.xref.RFC2049.1">A.2</a></li> 5138 5137 </ul> 5139 5138 </li> 5140 <li><em>RFC2068</em> <a href="#rfc.xref.RFC2068.1">6.4</a>, <a href="#rfc.xref.RFC2068.2">6.4</a>, <a href="#RFC2068"><b>1 4.2</b></a>, <a href="#rfc.xref.RFC2068.3">B</a><ul>5139 <li><em>RFC2068</em> <a href="#rfc.xref.RFC2068.1">6.4</a>, <a href="#rfc.xref.RFC2068.2">6.4</a>, <a href="#RFC2068"><b>15.2</b></a>, <a href="#rfc.xref.RFC2068.3">B</a><ul> 5141 5140 <li><em>Section 10.3</em> <a href="#rfc.xref.RFC2068.2">6.4</a></li> 5142 5141 <li><em>Section 10.3.4</em> <a href="#rfc.xref.RFC2068.1">6.4</a></li> 5143 5142 </ul> 5144 5143 </li> 5145 <li><em>RFC2076</em> <a href="#RFC2076"><b>1 4.2</b></a>, <a href="#rfc.xref.RFC2076.1">B</a></li>5146 <li><em>RFC2119</em> <a href="#rfc.xref.RFC2119.1">1.1</a>, <a href="#RFC2119"><b>1 4.1</b></a></li>5147 <li><em>RFC2277</em> <a href="#rfc.xref.RFC2277.1"> 7.3</a>, <a href="#RFC2277"><b>14.2</b></a></li>5148 <li><em>RFC2295</em> <a href="#rfc.xref.RFC2295.1"> 9</a>, <a href="#RFC2295"><b>14.2</b></a></li>5149 <li><em>RFC2388</em> <a href="#rfc.xref.RFC2388.1"> 7.5.2</a>, <a href="#RFC2388"><b>14.2</b></a></li>5150 <li><em>RFC2557</em> <a href="#rfc.xref.RFC2557.1">1 0.8</a>, <a href="#RFC2557"><b>14.2</b></a>, <a href="#rfc.xref.RFC2557.2">A.6</a><ul>5151 <li><em>Section 4</em> <a href="#rfc.xref.RFC2557.1">1 0.8</a></li>5144 <li><em>RFC2076</em> <a href="#RFC2076"><b>15.2</b></a>, <a href="#rfc.xref.RFC2076.1">B</a></li> 5145 <li><em>RFC2119</em> <a href="#rfc.xref.RFC2119.1">1.1</a>, <a href="#RFC2119"><b>15.1</b></a></li> 5146 <li><em>RFC2277</em> <a href="#rfc.xref.RFC2277.1">8.3</a>, <a href="#RFC2277"><b>15.2</b></a></li> 5147 <li><em>RFC2295</em> <a href="#rfc.xref.RFC2295.1">10</a>, <a href="#RFC2295"><b>15.2</b></a></li> 5148 <li><em>RFC2388</em> <a href="#rfc.xref.RFC2388.1">8.5.2</a>, <a href="#RFC2388"><b>15.2</b></a></li> 5149 <li><em>RFC2557</em> <a href="#rfc.xref.RFC2557.1">11.8</a>, <a href="#RFC2557"><b>15.2</b></a>, <a href="#rfc.xref.RFC2557.2">A.6</a><ul> 5150 <li><em>Section 4</em> <a href="#rfc.xref.RFC2557.1">11.8</a></li> 5152 5151 </ul> 5153 5152 </li> 5154 <li><em>RFC2616</em> <a href="#rfc.xref.RFC2616.1">6.4</a>, <a href="#rfc.xref.RFC2616.2">1 0.4</a>, <a href="#RFC2616"><b>14.2</b></a>, <a href="#rfc.xref.RFC2616.3">F.1</a><ul>5153 <li><em>RFC2616</em> <a href="#rfc.xref.RFC2616.1">6.4</a>, <a href="#rfc.xref.RFC2616.2">11.4</a>, <a href="#RFC2616"><b>15.2</b></a>, <a href="#rfc.xref.RFC2616.3">F.1</a><ul> 5155 5154 <li><em>Section 10.3.8</em> <a href="#rfc.xref.RFC2616.1">6.4</a></li> 5156 <li><em>Section 14.4</em> <a href="#rfc.xref.RFC2616.2">1 0.4</a></li>5155 <li><em>Section 14.4</em> <a href="#rfc.xref.RFC2616.2">11.4</a></li> 5157 5156 </ul> 5158 5157 </li> 5159 <li><em>RFC2817</em> <a href="#rfc.xref.RFC2817.1">1 1.2</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>5160 <li><em>Section 7.1</em> <a href="#rfc.xref.RFC2817.1">1 1.2</a>, <a href="#rfc.xref.RFC2817.3">C</a></li>5158 <li><em>RFC2817</em> <a href="#rfc.xref.RFC2817.1">12.2</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> 5159 <li><em>Section 7.1</em> <a href="#rfc.xref.RFC2817.1">12.2</a>, <a href="#rfc.xref.RFC2817.3">C</a></li> 5161 5160 </ul> 5162 5161 </li> 5163 <li><em>RFC3629</em> <a href="#rfc.xref.RFC3629.1"> 7.3</a>, <a href="#RFC3629"><b>14.2</b></a></li>5164 <li><em>RFC3864</em> <a href="#rfc.xref.RFC3864.1">1 1.3</a>, <a href="#rfc.xref.RFC3864.2">11.3.1</a>, <a href="#RFC3864"><b>14.2</b></a><ul>5165 <li><em>Section 4.1</em> <a href="#rfc.xref.RFC3864.2">1 1.3.1</a></li>5162 <li><em>RFC3629</em> <a href="#rfc.xref.RFC3629.1">8.3</a>, <a href="#RFC3629"><b>15.2</b></a></li> 5163 <li><em>RFC3864</em> <a href="#rfc.xref.RFC3864.1">12.3</a>, <a href="#rfc.xref.RFC3864.2">12.3.1</a>, <a href="#RFC3864"><b>15.2</b></a><ul> 5164 <li><em>Section 4.1</em> <a href="#rfc.xref.RFC3864.2">12.3.1</a></li> 5166 5165 </ul> 5167 5166 </li> 5168 <li><em>RFC3986</em> <a href="#rfc.xref.RFC3986.1">1 0.13</a>, <a href="#rfc.xref.RFC3986.2">10.13</a>, <a href="#RFC3986"><b>14.1</b></a><ul>5169 <li><em>Section 4.2</em> <a href="#rfc.xref.RFC3986.1">1 0.13</a></li>5170 <li><em>Section 5</em> <a href="#rfc.xref.RFC3986.2">1 0.13</a></li>5167 <li><em>RFC3986</em> <a href="#rfc.xref.RFC3986.1">11.13</a>, <a href="#rfc.xref.RFC3986.2">11.13</a>, <a href="#RFC3986"><b>15.1</b></a><ul> 5168 <li><em>Section 4.2</em> <a href="#rfc.xref.RFC3986.1">11.13</a></li> 5169 <li><em>Section 5</em> <a href="#rfc.xref.RFC3986.2">11.13</a></li> 5171 5170 </ul> 5172 5171 </li> 5173 <li><em>RFC4288</em> <a href="#rfc.xref.RFC4288.1"> 7.5</a>, <a href="#RFC4288"><b>14.2</b></a></li>5174 <li><em>RFC4647</em> <a href="#rfc.xref.RFC4647.1">1 0.4</a>, <a href="#rfc.xref.RFC4647.2">10.4</a>, <a href="#rfc.xref.RFC4647.3">10.4</a>, <a href="#rfc.xref.RFC4647.4">10.4</a>, <a href="#RFC4647"><b>14.1</b></a><ul>5175 <li><em>Section 2.1</em> <a href="#rfc.xref.RFC4647.1">1 0.4</a></li>5176 <li><em>Section 2.3</em> <a href="#rfc.xref.RFC4647.2">1 0.4</a></li>5177 <li><em>Section 3</em> <a href="#rfc.xref.RFC4647.3">1 0.4</a></li>5178 <li><em>Section 3.3.1</em> <a href="#rfc.xref.RFC4647.4">1 0.4</a></li>5172 <li><em>RFC4288</em> <a href="#rfc.xref.RFC4288.1">8.5</a>, <a href="#RFC4288"><b>15.2</b></a></li> 5173 <li><em>RFC4647</em> <a href="#rfc.xref.RFC4647.1">11.4</a>, <a href="#rfc.xref.RFC4647.2">11.4</a>, <a href="#rfc.xref.RFC4647.3">11.4</a>, <a href="#rfc.xref.RFC4647.4">11.4</a>, <a href="#RFC4647"><b>15.1</b></a><ul> 5174 <li><em>Section 2.1</em> <a href="#rfc.xref.RFC4647.1">11.4</a></li> 5175 <li><em>Section 2.3</em> <a href="#rfc.xref.RFC4647.2">11.4</a></li> 5176 <li><em>Section 3</em> <a href="#rfc.xref.RFC4647.3">11.4</a></li> 5177 <li><em>Section 3.3.1</em> <a href="#rfc.xref.RFC4647.4">11.4</a></li> 5179 5178 </ul> 5180 5179 </li> 5181 <li><em>RFC5226</em> <a href="#rfc.xref.RFC5226.1">1 1.1.1</a>, <a href="#rfc.xref.RFC5226.2">11.2.1</a>, <a href="#rfc.xref.RFC5226.3">11.4.1</a>, <a href="#RFC5226"><b>14.2</b></a><ul>5182 <li><em>Section 4.1</em> <a href="#rfc.xref.RFC5226.1">1 1.1.1</a>, <a href="#rfc.xref.RFC5226.2">11.2.1</a>, <a href="#rfc.xref.RFC5226.3">11.4.1</a></li>5180 <li><em>RFC5226</em> <a href="#rfc.xref.RFC5226.1">12.1.1</a>, <a href="#rfc.xref.RFC5226.2">12.2.1</a>, <a href="#rfc.xref.RFC5226.3">12.4.1</a>, <a href="#RFC5226"><b>15.2</b></a><ul> 5181 <li><em>Section 4.1</em> <a href="#rfc.xref.RFC5226.1">12.1.1</a>, <a href="#rfc.xref.RFC5226.2">12.2.1</a>, <a href="#rfc.xref.RFC5226.3">12.4.1</a></li> 5183 5182 </ul> 5184 5183 </li> 5185 <li><em>RFC5234</em> <a href="#rfc.xref.RFC5234.1">1.2</a>, <a href="#rfc.xref.RFC5234.2">1 1.3.1</a>, <a href="#RFC5234"><b>14.1</b></a>, <a href="#rfc.xref.RFC5234.3">D</a><ul>5184 <li><em>RFC5234</em> <a href="#rfc.xref.RFC5234.1">1.2</a>, <a href="#rfc.xref.RFC5234.2">12.3.1</a>, <a href="#RFC5234"><b>15.1</b></a>, <a href="#rfc.xref.RFC5234.3">D</a><ul> 5186 5185 <li><em>Appendix B.1</em> <a href="#rfc.xref.RFC5234.3">D</a></li> 5187 5186 </ul> 5188 5187 </li> 5189 <li><em>RFC5322</em> <a href="#rfc.xref.RFC5322.1"> 7.1</a>, <a href="#rfc.xref.RFC5322.2">10.10</a>, <a href="#rfc.xref.RFC5322.3">10.12</a>, <a href="#rfc.xref.RFC5322.4">10.12</a>, <a href="#RFC5322"><b>14.2</b></a>, <a href="#rfc.xref.RFC5322.5">A</a><ul>5190 <li><em>Section 3.3</em> <a href="#rfc.xref.RFC5322.1"> 7.1</a></li>5191 <li><em>Section 3.4</em> <a href="#rfc.xref.RFC5322.3">1 0.12</a>, <a href="#rfc.xref.RFC5322.4">10.12</a></li>5192 <li><em>Section 3.6.1</em> <a href="#rfc.xref.RFC5322.2">1 0.10</a></li>5188 <li><em>RFC5322</em> <a href="#rfc.xref.RFC5322.1">8.1</a>, <a href="#rfc.xref.RFC5322.2">11.10</a>, <a href="#rfc.xref.RFC5322.3">11.12</a>, <a href="#rfc.xref.RFC5322.4">11.12</a>, <a href="#RFC5322"><b>15.2</b></a>, <a href="#rfc.xref.RFC5322.5">A</a><ul> 5189 <li><em>Section 3.3</em> <a href="#rfc.xref.RFC5322.1">8.1</a></li> 5190 <li><em>Section 3.4</em> <a href="#rfc.xref.RFC5322.3">11.12</a>, <a href="#rfc.xref.RFC5322.4">11.12</a></li> 5191 <li><em>Section 3.6.1</em> <a href="#rfc.xref.RFC5322.2">11.10</a></li> 5193 5192 </ul> 5194 5193 </li> 5195 <li><em>RFC5646</em> <a href="#rfc.xref.RFC5646.1"> 7.6</a>, <a href="#rfc.xref.RFC5646.2">7.6</a>, <a href="#rfc.xref.RFC5646.3">7.6</a>, <a href="#RFC5646"><b>14.1</b></a><ul>5196 <li><em>Section 2.1</em> <a href="#rfc.xref.RFC5646.2"> 7.6</a></li>5194 <li><em>RFC5646</em> <a href="#rfc.xref.RFC5646.1">8.6</a>, <a href="#rfc.xref.RFC5646.2">8.6</a>, <a href="#rfc.xref.RFC5646.3">8.6</a>, <a href="#RFC5646"><b>15.1</b></a><ul> 5195 <li><em>Section 2.1</em> <a href="#rfc.xref.RFC5646.2">8.6</a></li> 5197 5196 </ul> 5198 5197 </li> 5199 <li><em>RFC5789</em> <a href="#rfc.xref.RFC5789.1">4.3.4</a>, <a href="#RFC5789"><b>1 4.2</b></a></li>5200 <li><em>RFC5987</em> <a href="#rfc.xref.RFC5987.1">1 1.3.1</a>, <a href="#RFC5987"><b>14.2</b></a></li>5201 <li><em>RFC6151</em> <a href="#RFC6151"><b>1 4.2</b></a>, <a href="#rfc.xref.RFC6151.1">C</a></li>5202 <li><em>RFC6266</em> <a href="#RFC6266"><b>1 4.2</b></a>, <a href="#rfc.xref.RFC6266.1">B</a>, <a href="#rfc.xref.RFC6266.2">C</a></li>5198 <li><em>RFC5789</em> <a href="#rfc.xref.RFC5789.1">4.3.4</a>, <a href="#RFC5789"><b>15.2</b></a></li> 5199 <li><em>RFC5987</em> <a href="#rfc.xref.RFC5987.1">12.3.1</a>, <a href="#RFC5987"><b>15.2</b></a></li> 5200 <li><em>RFC6151</em> <a href="#RFC6151"><b>15.2</b></a>, <a href="#rfc.xref.RFC6151.1">C</a></li> 5201 <li><em>RFC6266</em> <a href="#RFC6266"><b>15.2</b></a>, <a href="#rfc.xref.RFC6266.1">B</a>, <a href="#rfc.xref.RFC6266.2">C</a></li> 5203 5202 </ul> 5204 5203 </li> … … 5206 5205 <li>safe <a href="#rfc.iref.s.2"><b>4.2.1</b></a></li> 5207 5206 <li>selected representation <a href="#rfc.iref.s.1"><b>3.2</b></a></li> 5208 <li>Server header field <a href="#rfc.xref.header.server.1"> 5.6</a>, <a href="#rfc.iref.s.44"><b>10.17</b></a>, <a href="#rfc.xref.header.server.2">11.3.2</a>, <a href="#rfc.xref.header.server.3">12.1</a>, <a href="#rfc.xref.header.server.4">C</a></li>5207 <li>Server header field <a href="#rfc.xref.header.server.1">7</a>, <a href="#rfc.iref.s.44"><b>11.17</b></a>, <a href="#rfc.xref.header.server.2">12.3.2</a>, <a href="#rfc.xref.header.server.3">13.1</a>, <a href="#rfc.xref.header.server.4">C</a></li> 5209 5208 <li>Status Codes 5210 5209 <ul> 5211 <li>100 Continue <a href="#rfc.xref.status.100.1">6.1</a>, <a href="#rfc.iref.s.4"><b>6.2.1</b></a>, <a href="#rfc.xref.status.100.2">1 1.2.3</a></li>5212 <li>101 Switching Protocols <a href="#rfc.xref.status.101.1">6.1</a>, <a href="#rfc.iref.s.5"><b>6.2.2</b></a>, <a href="#rfc.xref.status.101.2">1 1.2.3</a></li>5213 <li>200 OK <a href="#rfc.xref.status.200.1">6.1</a>, <a href="#rfc.iref.s.7"><b>6.3.1</b></a>, <a href="#rfc.xref.status.200.2">1 1.2.3</a></li>5214 <li>201 Created <a href="#rfc.xref.status.201.1">6.1</a>, <a href="#rfc.iref.s.8"><b>6.3.2</b></a>, <a href="#rfc.xref.status.201.2">1 1.2.3</a></li>5215 <li>202 Accepted <a href="#rfc.xref.status.202.1">6.1</a>, <a href="#rfc.iref.s.9"><b>6.3.3</b></a>, <a href="#rfc.xref.status.202.2">1 1.2.3</a></li>5216 <li>203 Non-Authoritative Information <a href="#rfc.xref.status.203.1">6.1</a>, <a href="#rfc.iref.s.10"><b>6.3.4</b></a>, <a href="#rfc.xref.status.203.2">1 1.2.3</a>, <a href="#rfc.xref.status.203.3">C</a></li>5217 <li>204 No Content <a href="#rfc.xref.status.204.1">6.1</a>, <a href="#rfc.iref.s.11"><b>6.3.5</b></a>, <a href="#rfc.xref.status.204.2">1 1.2.3</a></li>5218 <li>205 Reset Content <a href="#rfc.xref.status.205.1">6.1</a>, <a href="#rfc.iref.s.12"><b>6.3.6</b></a>, <a href="#rfc.xref.status.205.2">1 1.2.3</a></li>5219 <li>300 Multiple Choices <a href="#rfc.xref.status.300.1">6.1</a>, <a href="#rfc.iref.s.14"><b>6.4.1</b></a>, <a href="#rfc.xref.status.300.2">1 1.2.3</a></li>5220 <li>301 Moved Permanently <a href="#rfc.xref.status.301.1">6.1</a>, <a href="#rfc.iref.s.15"><b>6.4.2</b></a>, <a href="#rfc.xref.status.301.2">1 1.2.3</a>, <a href="#rfc.xref.status.301.3">C</a></li>5221 <li>302 Found <a href="#rfc.xref.status.302.1">6.1</a>, <a href="#rfc.iref.s.16"><b>6.4.3</b></a>, <a href="#rfc.xref.status.302.2">1 1.2.3</a>, <a href="#rfc.xref.status.302.3">C</a></li>5222 <li>303 See Other <a href="#rfc.xref.status.303.1">6.1</a>, <a href="#rfc.iref.s.17"><b>6.4.4</b></a>, <a href="#rfc.xref.status.303.2">1 1.2.3</a></li>5223 <li>305 Use Proxy <a href="#rfc.xref.status.305.1">6.1</a>, <a href="#rfc.iref.s.18"><b>6.4.5</b></a>, <a href="#rfc.xref.status.305.2">1 1.2.3</a>, <a href="#rfc.xref.status.305.3">C</a></li>5224 <li>306 (Unused) <a href="#rfc.iref.s.19"><b>6.4.6</b></a>, <a href="#rfc.xref.status.306.1">1 1.2.3</a></li>5225 <li>307 Temporary Redirect <a href="#rfc.xref.status.307.1">6.1</a>, <a href="#rfc.iref.s.20"><b>6.4.7</b></a>, <a href="#rfc.xref.status.307.2">1 1.2.3</a>, <a href="#rfc.xref.status.307.3">C</a></li>5226 <li>400 Bad Request <a href="#rfc.xref.status.400.1">6.1</a>, <a href="#rfc.iref.s.22"><b>6.5.1</b></a>, <a href="#rfc.xref.status.400.2">1 1.2.3</a></li>5227 <li>402 Payment Required <a href="#rfc.xref.status.402.1">6.1</a>, <a href="#rfc.iref.s.23"><b>6.5.2</b></a>, <a href="#rfc.xref.status.402.2">1 1.2.3</a></li>5228 <li>403 Forbidden <a href="#rfc.xref.status.403.1">6.1</a>, <a href="#rfc.iref.s.24"><b>6.5.3</b></a>, <a href="#rfc.xref.status.403.2">1 1.2.3</a></li>5229 <li>404 Not Found <a href="#rfc.xref.status.404.1">6.1</a>, <a href="#rfc.iref.s.25"><b>6.5.4</b></a>, <a href="#rfc.xref.status.404.2">1 1.2.3</a></li>5230 <li>405 Method Not Allowed <a href="#rfc.xref.status.405.1">6.1</a>, <a href="#rfc.iref.s.26"><b>6.5.5</b></a>, <a href="#rfc.xref.status.405.2">1 1.2.3</a></li>5231 <li>406 Not Acceptable <a href="#rfc.xref.status.406.1">6.1</a>, <a href="#rfc.iref.s.27"><b>6.5.6</b></a>, <a href="#rfc.xref.status.406.2">1 1.2.3</a></li>5232 <li>408 Request Timeout <a href="#rfc.xref.status.408.1">6.1</a>, <a href="#rfc.iref.s.28"><b>6.5.7</b></a>, <a href="#rfc.xref.status.408.2">1 1.2.3</a></li>5233 <li>409 Conflict <a href="#rfc.xref.status.409.1">6.1</a>, <a href="#rfc.iref.s.29"><b>6.5.8</b></a>, <a href="#rfc.xref.status.409.2">1 1.2.3</a></li>5234 <li>410 Gone <a href="#rfc.xref.status.410.1">6.1</a>, <a href="#rfc.iref.s.30"><b>6.5.9</b></a>, <a href="#rfc.xref.status.410.2">1 1.2.3</a></li>5235 <li>411 Length Required <a href="#rfc.xref.status.411.1">6.1</a>, <a href="#rfc.iref.s.31"><b>6.5.10</b></a>, <a href="#rfc.xref.status.411.2">1 1.2.3</a></li>5236 <li>413 Request Representation Too Large <a href="#rfc.xref.status.413.1">6.1</a>, <a href="#rfc.iref.s.32"><b>6.5.11</b></a>, <a href="#rfc.xref.status.413.2">1 1.2.3</a></li>5237 <li>414 URI Too Long <a href="#rfc.xref.status.414.1">6.1</a>, <a href="#rfc.iref.s.33"><b>6.5.12</b></a>, <a href="#rfc.xref.status.414.2">1 1.2.3</a></li>5238 <li>415 Unsupported Media Type <a href="#rfc.xref.status.415.1">6.1</a>, <a href="#rfc.iref.s.34"><b>6.5.13</b></a>, <a href="#rfc.xref.status.415.2">1 1.2.3</a></li>5239 <li>417 Expectation Failed <a href="#rfc.xref.status.417.1">6.1</a>, <a href="#rfc.iref.s.35"><b>6.5.14</b></a>, <a href="#rfc.xref.status.417.2">1 1.2.3</a></li>5240 <li>426 Upgrade Required <a href="#rfc.xref.status.426.1">6.1</a>, <a href="#rfc.iref.s.36"><b>6.5.15</b></a>, <a href="#rfc.xref.status.426.2">1 1.2.3</a>, <a href="#rfc.xref.status.426.3">C</a></li>5241 <li>500 Internal Server Error <a href="#rfc.xref.status.500.1">6.1</a>, <a href="#rfc.iref.s.38"><b>6.6.1</b></a>, <a href="#rfc.xref.status.500.2">1 1.2.3</a></li>5242 <li>501 Not Implemented <a href="#rfc.xref.status.501.1">6.1</a>, <a href="#rfc.iref.s.39"><b>6.6.2</b></a>, <a href="#rfc.xref.status.501.2">1 1.2.3</a></li>5243 <li>502 Bad Gateway <a href="#rfc.xref.status.502.1">6.1</a>, <a href="#rfc.iref.s.40"><b>6.6.3</b></a>, <a href="#rfc.xref.status.502.2">1 1.2.3</a></li>5244 <li>503 Service Unavailable <a href="#rfc.xref.status.503.1">6.1</a>, <a href="#rfc.iref.s.41"><b>6.6.4</b></a>, <a href="#rfc.xref.status.503.2">1 1.2.3</a></li>5245 <li>504 Gateway Timeout <a href="#rfc.xref.status.504.1">6.1</a>, <a href="#rfc.iref.s.42"><b>6.6.5</b></a>, <a href="#rfc.xref.status.504.2">1 1.2.3</a></li>5246 <li>505 HTTP Version Not Supported <a href="#rfc.xref.status.505.1">6.1</a>, <a href="#rfc.iref.s.43"><b>6.6.6</b></a>, <a href="#rfc.xref.status.505.2">1 1.2.3</a></li>5210 <li>100 Continue <a href="#rfc.xref.status.100.1">6.1</a>, <a href="#rfc.iref.s.4"><b>6.2.1</b></a>, <a href="#rfc.xref.status.100.2">12.2.3</a></li> 5211 <li>101 Switching Protocols <a href="#rfc.xref.status.101.1">6.1</a>, <a href="#rfc.iref.s.5"><b>6.2.2</b></a>, <a href="#rfc.xref.status.101.2">12.2.3</a></li> 5212 <li>200 OK <a href="#rfc.xref.status.200.1">6.1</a>, <a href="#rfc.iref.s.7"><b>6.3.1</b></a>, <a href="#rfc.xref.status.200.2">12.2.3</a></li> 5213 <li>201 Created <a href="#rfc.xref.status.201.1">6.1</a>, <a href="#rfc.iref.s.8"><b>6.3.2</b></a>, <a href="#rfc.xref.status.201.2">12.2.3</a></li> 5214 <li>202 Accepted <a href="#rfc.xref.status.202.1">6.1</a>, <a href="#rfc.iref.s.9"><b>6.3.3</b></a>, <a href="#rfc.xref.status.202.2">12.2.3</a></li> 5215 <li>203 Non-Authoritative Information <a href="#rfc.xref.status.203.1">6.1</a>, <a href="#rfc.iref.s.10"><b>6.3.4</b></a>, <a href="#rfc.xref.status.203.2">12.2.3</a>, <a href="#rfc.xref.status.203.3">C</a></li> 5216 <li>204 No Content <a href="#rfc.xref.status.204.1">6.1</a>, <a href="#rfc.iref.s.11"><b>6.3.5</b></a>, <a href="#rfc.xref.status.204.2">12.2.3</a></li> 5217 <li>205 Reset Content <a href="#rfc.xref.status.205.1">6.1</a>, <a href="#rfc.iref.s.12"><b>6.3.6</b></a>, <a href="#rfc.xref.status.205.2">12.2.3</a></li> 5218 <li>300 Multiple Choices <a href="#rfc.xref.status.300.1">6.1</a>, <a href="#rfc.iref.s.14"><b>6.4.1</b></a>, <a href="#rfc.xref.status.300.2">12.2.3</a></li> 5219 <li>301 Moved Permanently <a href="#rfc.xref.status.301.1">6.1</a>, <a href="#rfc.iref.s.15"><b>6.4.2</b></a>, <a href="#rfc.xref.status.301.2">12.2.3</a>, <a href="#rfc.xref.status.301.3">C</a></li> 5220 <li>302 Found <a href="#rfc.xref.status.302.1">6.1</a>, <a href="#rfc.iref.s.16"><b>6.4.3</b></a>, <a href="#rfc.xref.status.302.2">12.2.3</a>, <a href="#rfc.xref.status.302.3">C</a></li> 5221 <li>303 See Other <a href="#rfc.xref.status.303.1">6.1</a>, <a href="#rfc.iref.s.17"><b>6.4.4</b></a>, <a href="#rfc.xref.status.303.2">12.2.3</a></li> 5222 <li>305 Use Proxy <a href="#rfc.xref.status.305.1">6.1</a>, <a href="#rfc.iref.s.18"><b>6.4.5</b></a>, <a href="#rfc.xref.status.305.2">12.2.3</a>, <a href="#rfc.xref.status.305.3">C</a></li> 5223 <li>306 (Unused) <a href="#rfc.iref.s.19"><b>6.4.6</b></a>, <a href="#rfc.xref.status.306.1">12.2.3</a></li> 5224 <li>307 Temporary Redirect <a href="#rfc.xref.status.307.1">6.1</a>, <a href="#rfc.iref.s.20"><b>6.4.7</b></a>, <a href="#rfc.xref.status.307.2">12.2.3</a>, <a href="#rfc.xref.status.307.3">C</a></li> 5225 <li>400 Bad Request <a href="#rfc.xref.status.400.1">6.1</a>, <a href="#rfc.iref.s.22"><b>6.5.1</b></a>, <a href="#rfc.xref.status.400.2">12.2.3</a></li> 5226 <li>402 Payment Required <a href="#rfc.xref.status.402.1">6.1</a>, <a href="#rfc.iref.s.23"><b>6.5.2</b></a>, <a href="#rfc.xref.status.402.2">12.2.3</a></li> 5227 <li>403 Forbidden <a href="#rfc.xref.status.403.1">6.1</a>, <a href="#rfc.iref.s.24"><b>6.5.3</b></a>, <a href="#rfc.xref.status.403.2">12.2.3</a></li> 5228 <li>404 Not Found <a href="#rfc.xref.status.404.1">6.1</a>, <a href="#rfc.iref.s.25"><b>6.5.4</b></a>, <a href="#rfc.xref.status.404.2">12.2.3</a></li> 5229 <li>405 Method Not Allowed <a href="#rfc.xref.status.405.1">6.1</a>, <a href="#rfc.iref.s.26"><b>6.5.5</b></a>, <a href="#rfc.xref.status.405.2">12.2.3</a></li> 5230 <li>406 Not Acceptable <a href="#rfc.xref.status.406.1">6.1</a>, <a href="#rfc.iref.s.27"><b>6.5.6</b></a>, <a href="#rfc.xref.status.406.2">12.2.3</a></li> 5231 <li>408 Request Timeout <a href="#rfc.xref.status.408.1">6.1</a>, <a href="#rfc.iref.s.28"><b>6.5.7</b></a>, <a href="#rfc.xref.status.408.2">12.2.3</a></li> 5232 <li>409 Conflict <a href="#rfc.xref.status.409.1">6.1</a>, <a href="#rfc.iref.s.29"><b>6.5.8</b></a>, <a href="#rfc.xref.status.409.2">12.2.3</a></li> 5233 <li>410 Gone <a href="#rfc.xref.status.410.1">6.1</a>, <a href="#rfc.iref.s.30"><b>6.5.9</b></a>, <a href="#rfc.xref.status.410.2">12.2.3</a></li> 5234 <li>411 Length Required <a href="#rfc.xref.status.411.1">6.1</a>, <a href="#rfc.iref.s.31"><b>6.5.10</b></a>, <a href="#rfc.xref.status.411.2">12.2.3</a></li> 5235 <li>413 Request Representation Too Large <a href="#rfc.xref.status.413.1">6.1</a>, <a href="#rfc.iref.s.32"><b>6.5.11</b></a>, <a href="#rfc.xref.status.413.2">12.2.3</a></li> 5236 <li>414 URI Too Long <a href="#rfc.xref.status.414.1">6.1</a>, <a href="#rfc.iref.s.33"><b>6.5.12</b></a>, <a href="#rfc.xref.status.414.2">12.2.3</a></li> 5237 <li>415 Unsupported Media Type <a href="#rfc.xref.status.415.1">6.1</a>, <a href="#rfc.iref.s.34"><b>6.5.13</b></a>, <a href="#rfc.xref.status.415.2">12.2.3</a></li> 5238 <li>417 Expectation Failed <a href="#rfc.xref.status.417.1">6.1</a>, <a href="#rfc.iref.s.35"><b>6.5.14</b></a>, <a href="#rfc.xref.status.417.2">12.2.3</a></li> 5239 <li>426 Upgrade Required <a href="#rfc.xref.status.426.1">6.1</a>, <a href="#rfc.iref.s.36"><b>6.5.15</b></a>, <a href="#rfc.xref.status.426.2">12.2.3</a>, <a href="#rfc.xref.status.426.3">C</a></li> 5240 <li>500 Internal Server Error <a href="#rfc.xref.status.500.1">6.1</a>, <a href="#rfc.iref.s.38"><b>6.6.1</b></a>, <a href="#rfc.xref.status.500.2">12.2.3</a></li> 5241 <li>501 Not Implemented <a href="#rfc.xref.status.501.1">6.1</a>, <a href="#rfc.iref.s.39"><b>6.6.2</b></a>, <a href="#rfc.xref.status.501.2">12.2.3</a></li> 5242 <li>502 Bad Gateway <a href="#rfc.xref.status.502.1">6.1</a>, <a href="#rfc.iref.s.40"><b>6.6.3</b></a>, <a href="#rfc.xref.status.502.2">12.2.3</a></li> 5243 <li>503 Service Unavailable <a href="#rfc.xref.status.503.1">6.1</a>, <a href="#rfc.iref.s.41"><b>6.6.4</b></a>, <a href="#rfc.xref.status.503.2">12.2.3</a></li> 5244 <li>504 Gateway Timeout <a href="#rfc.xref.status.504.1">6.1</a>, <a href="#rfc.iref.s.42"><b>6.6.5</b></a>, <a href="#rfc.xref.status.504.2">12.2.3</a></li> 5245 <li>505 HTTP Version Not Supported <a href="#rfc.xref.status.505.1">6.1</a>, <a href="#rfc.iref.s.43"><b>6.6.6</b></a>, <a href="#rfc.xref.status.505.2">12.2.3</a></li> 5247 5246 </ul> 5248 5247 </li> … … 5256 5255 </ul> 5257 5256 </li> 5258 <li><em>status-308</em> <a href="#rfc.xref.status-308.1">6.4.7</a>, <a href="#status-308"><b>1 4.2</b></a></li>5257 <li><em>status-308</em> <a href="#rfc.xref.status-308.1">6.4.7</a>, <a href="#status-308"><b>15.2</b></a></li> 5259 5258 </ul> 5260 5259 </li> 5261 5260 <li><a id="rfc.index.T" href="#rfc.index.T"><b>T</b></a><ul> 5262 <li>TRACE method <a href="#rfc.xref.TRACE.1">4.1</a>, <a href="#rfc.iref.t.1"><b>4.3.8</b></a>, <a href="#rfc.xref.TRACE.2">1 0.14</a>, <a href="#rfc.xref.TRACE.3">11.1.3</a>, <a href="#rfc.xref.TRACE.4">12.1</a></li>5261 <li>TRACE method <a href="#rfc.xref.TRACE.1">4.1</a>, <a href="#rfc.iref.t.1"><b>4.3.8</b></a>, <a href="#rfc.xref.TRACE.2">11.14</a>, <a href="#rfc.xref.TRACE.3">12.1.3</a>, <a href="#rfc.xref.TRACE.4">13.1</a></li> 5263 5262 </ul> 5264 5263 </li> 5265 5264 <li><a id="rfc.index.U" href="#rfc.index.U"><b>U</b></a><ul> 5266 <li>User-Agent header field <a href="#rfc.xref.header.user-agent.1">5 .5</a>, <a href="#rfc.xref.header.user-agent.2">9.1</a>, <a href="#rfc.iref.u.1"><b>10.18</b></a>, <a href="#rfc.xref.header.user-agent.3">11.3.2</a>, <a href="#rfc.xref.header.user-agent.4">12.1</a></li>5265 <li>User-Agent header field <a href="#rfc.xref.header.user-agent.1">5</a>, <a href="#rfc.xref.header.user-agent.2">10.1</a>, <a href="#rfc.iref.u.1"><b>11.18</b></a>, <a href="#rfc.xref.header.user-agent.3">12.3.2</a>, <a href="#rfc.xref.header.user-agent.4">13.1</a></li> 5267 5266 </ul> 5268 5267 </li> -
draft-ietf-httpbis/latest/p2-semantics.xml
r1850 r1851 224 224 intentions defined by each request method (<xref target="methods"/>), 225 225 extensions to those semantics that might be described in request header 226 fields (<xref target="request. fields"/>),226 fields (<xref target="request.header.fields"/>), 227 227 the meaning of status codes to indicate a machine-readable response 228 228 (<xref target="status.codes"/>), and other control data 229 and resource metadata that might be given in response header fields. 229 and resource metadata that might be given in response header fields 230 (<xref target="response.header.fields"/>). 230 231 </t> 231 232 <t><iref item="content negotiation"/> … … 280 281 request semantics, which is made possible by vesting the request 281 282 semantics in the request method (<xref target="methods"/>) and a few 282 request-modifying header fields (<xref target="request. fields"/>).283 request-modifying header fields (<xref target="request.header.fields"/>). 283 284 Resource owners &SHOULD-NOT; include request semantics within a URI, 284 285 such as by specifying an action to invoke within the path or query … … 471 472 and what is expected by the client as a successful result. The request 472 473 semantics &MAY; be further specialized by the semantics of some header 473 fields when present in a request (<xref target="request. fields"/>) if474 those additional semantics do not conflict with the method.474 fields when present in a request (<xref target="request.header.fields"/>) 475 if those additional semantics do not conflict with the method. 475 476 </t> 476 477 <figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="method"/> … … 1131 1132 </section> 1132 1133 1133 <section title="Header Fields" anchor="header.fields">1134 1135 <section title="Request-modifier Header Fields" anchor="request.fields">1136 </section>1137 1138 <section title="Status-modifier Header Fields" anchor="response.fields">1139 </section>1140 1141 <section title="Resource Metadata Fields" anchor="resource.fields">1142 </section>1143 1144 <section title="Payload Metadata Fields" anchor="payload.fields">1145 </section>1146 1147 1134 <section title="Request Header Fields" anchor="request.header.fields"> 1148 1135 <x:anchor-alias value="request-header"/> … … 1178 1165 <c>User-Agent</c> <c><xref target="header.user-agent"/></c> 1179 1166 </texttable> 1180 </section> 1181 1182 <section title="Response Header Fields" anchor="response.header.fields"> 1183 <x:anchor-alias value="response-header"/> 1184 <t> 1185 The response header fields allow the server to pass additional 1186 information about the response which cannot be placed in the status-line. 1187 These header fields give information about the server and about 1188 further access to the target resource (&effective-request-uri;). 1189 </t> 1190 <texttable align="left"> 1191 <ttcol>Header Field Name</ttcol><ttcol>Defined in...</ttcol> 1192 1193 <c>Accept-Ranges</c> <c>&header-accept-ranges;</c> 1194 <c>Age</c> <c>&header-age;</c> 1195 <c>Allow</c> <c><xref target="header.allow"/></c> 1196 <c>Date</c> <c><xref target="header.date"/></c> 1197 <c>ETag</c> <c>&header-etag;</c> 1198 <c>Location</c> <c><xref target="header.location"/></c> 1199 <c>Proxy-Authenticate</c> <c>&header-proxy-authenticate;</c> 1200 <c>Retry-After</c> <c><xref target="header.retry-after"/></c> 1201 <c>Server</c> <c><xref target="header.server"/></c> 1202 <c>Vary</c> <c>&header-vary;</c> 1203 <c>WWW-Authenticate</c> <c>&header-www-authenticate;</c> 1204 </texttable> 1205 </section> 1206 1167 1168 <section title="Controls" anchor="request.controls"> 1169 </section> 1170 1171 <section title="Conditionals" anchor="request.conditionals"> 1172 </section> 1173 1174 <section title="Content Negotiation" anchor="request.conneg"> 1175 </section> 1176 1177 <section title="Information" anchor="request.inform"> 1178 </section> 1207 1179 </section> 1208 1180 … … 2207 2179 </section> 2208 2180 </section> 2181 </section> 2182 2183 <section title="Response Header Fields" anchor="response.header.fields"> 2184 <x:anchor-alias value="response-header"/> 2185 <t> 2186 The response header fields allow the server to pass additional 2187 information about the response which cannot be placed in the status-line. 2188 These header fields give information about the server and about 2189 further access to the target resource (&effective-request-uri;). 2190 </t> 2191 <texttable align="left"> 2192 <ttcol>Header Field Name</ttcol><ttcol>Defined in...</ttcol> 2193 2194 <c>Accept-Ranges</c> <c>&header-accept-ranges;</c> 2195 <c>Age</c> <c>&header-age;</c> 2196 <c>Allow</c> <c><xref target="header.allow"/></c> 2197 <c>Date</c> <c><xref target="header.date"/></c> 2198 <c>ETag</c> <c>&header-etag;</c> 2199 <c>Location</c> <c><xref target="header.location"/></c> 2200 <c>Proxy-Authenticate</c> <c>&header-proxy-authenticate;</c> 2201 <c>Retry-After</c> <c><xref target="header.retry-after"/></c> 2202 <c>Server</c> <c><xref target="header.server"/></c> 2203 <c>Vary</c> <c>&header-vary;</c> 2204 <c>WWW-Authenticate</c> <c>&header-www-authenticate;</c> 2205 </texttable> 2209 2206 </section> 2210 2207
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